Easy Water Fasting Tips from a Guy Who Learned the Hard Way

These water fasting tips will help you overcome your doubts, inspire you to give it a go, and make your fasting experience a whole lot easier.


Don’t Be Stupid Like Me About Fasting

“Easy. Don’t eat.”

Stupidly, that’s all I thought I needed to know about fasting before I attempted my first extended water fast. That made the fast a lot harder than it needed to be.

I don’t recommend you do the same, which is why I put together these water fasting tips. They answer the questions I once had and am now often asked.

I did my best to write in simple English—not over-complicated doctor talk. And while I’m 100% unqualified, the scientific info here does come from a doctor, Dr. Jason Fung.

Fung’s book, The Complete Guide to Fasting, is the most easy-to-read, helpful, and motivating resource on fasting out there. Start with these tips, then if you want more detail, read the book.

Even though it’s long, I recommend you read through every tip below because the more you understand fasting and how and why to do it, the better your experience will be. Then, you’re more likely to fast again are really reap the benefits.

Don’t be stupid like me.

Fasting 101

What’s the difference between fasting and starving?

Dr. Fung answers this with a fun analogy:

Fasting is running for health. Starving is running because a lion’s chasing you.

Kim and family, including pregnant sister
One of these people should probably not be fasting.

Why shouldn’t I fast?

Don’t fast if you’re under eighteen years old, pregnant, or nursing.

And check with your doctor first if you’re taking any prescription or over-the-counter medications to treat pre-existing conditions.

Fasting may also be a bad idea if you have a hot date coming up, you have self-control issues, or have a big race, presentation, or building ahead of you. See our Why Fast? (And Why Not?) post for details.

If I’m perfectly healthy, why should I torture myself by fasting?

You brush your teeth right?

Well, fasting is the same thing, but for your body. It keeps your body and brain clean and hopefully working well for a long, long time. And there are not dentures for your body or brain (yet).

Also, if you read through the other water fasting tips, hopefully you’ll realize fasting isn’t “torture.” It may not be as pleasurable as eating cake or nachos, but it is an enlightening experience.

French press full of coffee
If you think you can survive without eating for a few days, but not without coffee, don’t worry.

What am I allowed to eat or drink while fasting?

This question isn’t as stupid as it seems. Even on a water fast, Dr. Fung says you can consume more than just water. And I highly recommend doing so to make the experience more pleasurable.

  • Not allowed: Diet Coke or Coke Zero or any other zero-calorie crap like that.
  • Allowed: Water flavored with coffee, tea, lime, any fruit infusion you can dream up, some apple cider vinegar, or sea salts; bone broth; multivitamins.
  • An easier alternative? Possibly. See “Is there an easier alternative?” under Understanding and Fighting Hunger, below.

Dr. Fung doesn’t mention it in his book, but what’s helped me stay hydrated—which is super important but difficult to do while fasting—is adding zero or very-low-calorie electrolyte powders to my water.

The first time I fasted for a prolonged period, I didn’t add electrolytes and felt light-headed and woozy whenever I made sudden movements. When I added electrolytes to my diet in future fasts, those sensations disappeared.

There’s no brand in particular that I’d recommend over any other. This powder on Amazon ticks all the boxes, gets great reviews, and only costs around 30 cents a serving. Alternatively, go to your local pharmacy and pick out whatever looks good to you.

Reader Tips: 

  • As a cheap, easy, and vegan alternative to bone broth, go to a Japanese grocery store and get some instant miso soup packets.
  • Chew on fennel seeds or mint leaves, suggests Emily in the comments of my post on what to expect from a 3-day fast if you’ve never fasted before.
  • Don’t drink too much water. Pascal points out that doing so, “flushes out the electrolytes you desperately need, especially when fasting.” He states that if you drink so much your urine is clear that’s a sign you’re drinking too much.

Benefits of Prolonged Fasting

What’s all the hype about?


  • Makes you think better and be more focused
  • Burns your fat
  • Lowers your blood sugar and cholesterol
  • Increases your energy
  • Extends your life (…as long as you do eventually go back to eating!)
  • Reverses aging
  • Is free

These are proven benefits. It’s a freaking miracle drug, minus the drug.

So what’s the catch? It requires serious self-control to refrain from that little habit we call eating.

Bodyfat DEXA scan results.
You’ll lose weight by fasting, but not as much as you might hope. (These images here are from a DEXA scan, which is the best way to track fat loss. Read our DEXA scan review for more info.)

Will I lose tons of weight if I do a 3, 5, or 7 day fast?

The good news is from a 5 day fast you can lose 10 pounds or more!

The bad news is that of those 10 pounds, 85% will be water.

Here’s the reality:

You can only expect to burn half a pound of fat (1,750 calories) a day while fasting, and that’s only after you burn off all the sugars in your body first, which can take up to two days. So if you do a 5-day fast, you might only burn 1.5 pounds of fat. And since average human weighs 137 pounds and has about 25% body fat, they have 34 pounds of fat to burn, meaning they’d only lose 4.4% of their body fat in a 5-day fast.

The huge potential weight-loss benefits are long-term.

If you continue with a healthy diet and periodic fasting, you will reset your metabolism which will cause a gradual decline in your fat levels and eventually lead to notable and very visible results. A fantastic book that explains this process and can get you on the right path is The Obesity Code, by Jason Fung.

Will I look any different after my fast?

Yeah, you’ll look hungry.

But really, even though you won’t burn that much fat—as explained in the previous question—you will notice some visual differences. Most notably, your stomach will deflate. It might even “cave in” like it did for me on my first three-day fast. But once you put some food back in you, it’ll reinflate.

I’ve also noticed that my skin gets nice and clear as long as I stay hydrated.

Chris taking a happy bite.
One surprise benefit of fasting is that it’ll enhance your appreciation for food. Nothing tastes better than that first bite after a long fast.

What other surprises can I look forward to from fasting?

If you have never had a day without food in your life, let alone multiple days in a row, fasting will boggle your mind in some surprising ways. You will:

  • Have so much extra time on your hands since you’re no longer cooking, eating, or taking dumps.
  • Wonder whether you need to brush your teeth or not.
  • Experience a de-bloating of your stomach, where it’s not less-fat, but sort of caves in
  • Start considering what other habits other than eating you can tinker with to experience a whole new perspective on life. (For more ideas, join us and thousands of others on Consider This.)
  • Appreciate food even more than ever when you get back to eating. No cherry ever tasted better than that first one I ate after my most recent five day fast.

How might fasting help me live longer?

Fasting gives your body a break from everyday work so it can do some long-overdue spring cleaning.

It finds the old and broken junk (in this case, junk = cells) and burns it for energy and protein. This is the junk that, if left to accumulate and fester, can lead to degenerative diseases like Alzheimer’s and cancer.

Fasting can also prevent the onset of type 2 diabetes, or reverse it for those who have it. We won’t get into the details here but, basically, it helps your body get more efficient at clearing out sugar from your bloodstream. The complete explanation is simple, just a bit long. You can read it in Dr. Fung’s book.

Can’t I just eat less instead of nothing at all for the same benefit?


When you cut calories, your body reacts by slowing your metabolism to cut the number of calories it burns. This makes you feel lethargic, foggy-minded, and always hungry. And for nothing, since you’re not burning more calories than you’re eating.

On the other hand, when you fast your body can’t reduce its metabolism down to zero to match your food intake, so it goes into crisis mode. It accelerates. Adrenaline, testosterone, and growth hormone kick into gear so you can get out there and hunt for food effectively. Or you get more work done at your desk.

What are the downsides?

Your brain will be so jacked up that you might find it hard to sleep (see the next tip to understand why).

You also might have to turn down invites to dinner and lunch parties.

And you won’t be able to eat free samples at Costco.

Common Misconceptions About Fasting

Won’t I feel like dogsh*t the whole time I’m fasting?

Quite the contrary. Aside from being a bit hungry (though less than you might think), you might actually feel great.

As explained two tips above, your body will be running at full blast and pumped full of hormones like adrenaline, human growth hormone, and testosterone.

Your brain will feel great too.

First of all, it will be getting more blood since none is needed for your digestive system. (This is also why you feel drowsy after eating too much.) Secondly, once it has run out of sugar to burn for fuel, it’ll start running off of ketones from fat. Your brain on ketones, in my experience, feels like it’s on Adderall—super focused, alert, and sharp.

How will I get any work done if I’m hungry all the time?

Not only won’t you feel hungry all the time, but your brain will feel sharper than ever. The energy that’s normally used by your digestive system gets channeled to your brain and after a couple days your brain will run out of fast-but-too-quickly-burning sugar and start running off the slow-burning rocket fuel of fat instead.

Another thing: Since you won’t be eating you’ll have a couple extra hours to your day. You can use those to work more, sleep more, or do anything you want with other than eat.

Won’t fasting cause me to lose muscle?

As Dr. Fung explains, that would be like storing firewood all summer, then, as soon as it gets cold, chopping up your couch and burning it instead.

Your body isn’t stupid. It treats fat like firewood and muscle like your precious couch. It preserves muscle up until it is desperately needed.

Isn’t fasting less safe or effective for women?

In the words of Dr. Fung, “Virtually all studies on fasting confirm that both men and women benefit from fasting…If anything, women tend to do better.”

So sorry ladies, you can’t use, “But it’s not safe for women!” as an excuse.

Understanding and Fighting Hunger

Chris staring at empty plate.
You won’t actually feel like this the entire time you’re fasting.

Won’t I feel hungry all the time?


And the lack of hunger you feel when fasting is the most surprising part about fasting (at least to me).

There are two main reasons why you won’t feel hungry: fat and ghrelin.


Your body’s go-to supply of fuel, sugar, will run out within a day or two of fasting. At this point, and only at this point, your body moves to its backup fuel source: fat.

Fat is something we all have a lot of (unless you’re an Olympic marathon runner or Mr. Olympia). As explained in an earlier tip, the average human has 34 pounds. That’s 68 days worth of fuel for your body to feed on. This means that when you fast not only is your body not hungry, but you’ve opened the doors to an all-you-can-eat buffet.


The hunger you feel has nothing to do with your stomach being empty. It’s entirely mental.

The hormone responsible is called ghrelin. Ghrelin comes and goes in cycles based on your routine eating times. This explains why you’re no hungrier for breakfast than for dinner despite the fact that it’s typically been longer since you last ate.

Fasting screws with ghrelin’s routine, which is an added benefit of doing it. The more you disturb your ghrelin cycle, the more confused your body gets, and the less ghrelin it produces. This means you’ll feel less hungry even after you stop your fast.

I’m not kidding. I’m 6’3” and 200+ pounds, very active, and I used to always be hungry and snack all the time. But since I got into fasting, I no longer crave food all day long. I still love eating, but I eat when I feel like it, not when ghrelin tells me too.

How can I prepare beforehand to make my fast easier?

Eat healthily. If you’re addicted to sugar and refined grains, you’re going to be fighting that addiction as well as hunger during your fast. That’s super tough, so the more you can kick your refined carb addiction before your fast, the better. You do this by eating whole, unprocessed foods, and a diet high in naturally occurring fats (i.e. no corn or vegetable oils).

Eat irregularly. As explained in the answer to “Won’t I feel hungry?” the more irregularly you eat the more you kill off the hormones that make you feel hungry.

Find a friend. Dr. Fung doesn’t mention it in his book, but what works for me too is to find a friend to join you on your fast-inating journey. They provide support and accountability and celebrate with you after.

Clear your calendar. You probably want to avoid dinner parties and lunch meetings. Stick to going for coffee or tea with friends.

How can I feel less hungry when I’m fasting

Start your day with a big glass of water. I like to add a squirt of fresh lime and some sea salt for flavor and so it doesn’t go right through me.

Then keep drinking water. Lots of it. Since you’re not getting any hydration from your food, you need to drink even more than normal.

To add a little bit of taste, infuse it with fruits or add coffee, green tea, cayenne, or cinnamon—all of which have hunger-suppressing properties.

And here’s a sneaky helpful water fasting tip to feel less hungry: Don’t tell anybody who doesn’t need to know that you’re fasting.

If you tell people and they’re nice and understanding, they’ll constantly remind you of your hunger by asking you how you’re feeling. If they’re nice and not understanding, they’ll try to stop you from “killing yourself.” And if they’re not nice and not understanding, like my friends are, they’ll torture you by eating the most delicious-smelling foods as close to your face as possible.

When can I expect to be the hungriest?

Strangely enough, you’ll probably be the hungriest during your first day or two. After that, your body will transition to burning fat for fuel and you’ll stop feeling as hungry.

Dr. Fung explains that this is why doctors advise three-to-seven-day fasts instead of two-day fasts. Once you’ve gotten through the hard part, the first two days, you may as well keep on going! The benefits actually increase with time (i.e. a 4-day fast is better for you than doing a 2-day fast twice.)

After you get past the two-day hurdle, the next time you’ll feel VERY hungry is right at the end of your fast and the end is near.

I’m in the middle of my fast and I feel horrible. What do I do?

Try drinking some bone broth. The salts and minerals will help.

If that doesn’t work and you’re feeling not just hungry but actually sick, take a drastic measure:

Eat something.

Break your fast. You’ll get ’em next time.

Chris and Dave eating after a five-day fast.
My friend Dave and I not at all following fasting best practices with a big feast to celebrate the end of a 5-day fast.

How should I break my fast?

Try to resist the formidable urge to stuff your face with chocolate cake, hamburgers, and beer to celebrate the end of a long fast. Your stomach and its microbiome will be in a sensitive state and especially vulnerable to any junk you shove into it. The longer your fast, the more careful you should be.

Try to avoid:

  • High carb meals. Processed carbs, in particular.
  • Nuts and seeds.
  • Raw cruciferous veggies.
  • Dairy and eggs.
  • Alcohol.

Your best bet is a fresh salad dressed with extra-virgin olive oil and maybe a bit of chicken or fish. Give that some time to settle in your stomach, see how you feel, and go from there.

Better yet, take advantage of this “new beginning” to get started on a healthier diet.

Is there an easier alternative to fasting?

According to Dr. Valter Longo, a world-leading longevity researcher, there may be.

At the University of Southern California’s Longevity Institute, he’s found that fasting can increase longevity… except for one big problem: He couldn’t get the people in his studies to stop eating for long enough to get the benefits!

To make fasting easier for them, he developed a clinically-proven “Fasting Mimicking Diet” that allows people to eat specific foods during a 5-day fast while still enjoying the benefits of fasting.

And now you can try the diet too.

The biggest downside is it costs $249 per 5-day package.

That said, the $249 cost is offset by the savings of not having to pay for any other food for five days and the package comes with a nutrition consultation session. Plus, Dr. Longo donates all profits from his 60% share in the company to his Create Cures Foundation, so most of your money’s going to a good cause. Still, $249 is too much for an underpaid blogger like me, but if you’re worried about not eating at all but want the benefits of fasting and have the cash, it’s worth a try.

Click here to see if this FMD is right for you.

Or, if you’re still skeptical like I was, read Dr. Longo’s book, The Longevity Diet, for more background. I found the book to be easy to understand with plenty of other interesting science and advice on how to eat for a long life.

All these fasting tips are helpful, but I’m still not sure I can do it. How can I motivate myself?

Try reading my own journal from my first-ever 3-day fast. I’d never even gone a day without food beforehand, so for me it was quite the experience. Your experience won’t be exactly the same, but maybe reading how mine went will inspire you or at least make you curious enough to try.

If you’re more of a dip-your-toes-in-the-water-before-cannonballing-in type of person, start with intermittent fasting to slowly condition your hunger hormones to be less hangry, horrible bosses.

Also take a look at my post on the surprising and motivating benefits of prolonged fasting.

Or, if you’re tired of reading my writing and stupid jokes, this video that Kim forwarded me today is pretty motivating:

YouTube video


Why should I trust your water fasting tips? Who are you?

Hey. I’m Chris. I’m a regular hungry human.

Only a couple of years ago, I ate four meals a day, snacked non-stop, and would never in a million years have considered fasting.

Honestly, I don’t remember what exactly got me started, but here I am, fasting regularly throughout the year. I just wish I’d been converted sooner. I like to think these water fasting tips would have convinced me.

I’m no doctor, but all the scientific information I share below is from one. It’s from the very best and most easy-to-understand book on fasting I’ve found, The Complete Guide to Fasting, by Jason Fung.

The Complete Guide to Fasting by Jason Fung

Is this list of water fasting tips a poorly-disguised book advertisement?

If it were, I would be the one being exploited even more than you.

Amazon, not Dr. Fung, does pay me a small commission if you buy The Complete Guide to Fasting through my link. But even if you and a hundred other people were to click the link and buy the book I’d only net about $75 total. Since I spent at least fifteen hours making this post, not to mention the time I spent reading his book, taking notes, and experimenting with fasting, and replying to comments, that’s a horrible wage.

I made this post because I truly believe fasting can improve people’s lives and of all the books, podcasts, and articles I’ve read, Dr. Fung’s was by far the best.

You didn’t answer my question. What do I do?

Check the hundreds of comments below. Odds are you’ll find some insight. Or maybe you’ll find inspiration from others’ experience.

And if you have an original question, I’ll get back to you as soon as possible and add to this list of water fasting tips accordingly. 

Related Reads

About the author

I'm Chris. Canadian, husband, dad, writer, investor, athlete, and obsessed explorer of the secrets to living a never-boring, always improving, unfollowable life story.

438 responses to “Easy Water Fasting Tips from a Guy Who Learned the Hard Way”

  1. Stephanie Avatar

    This was interesting and makes me want to try it. Thanks. Quick question – do you stick to a certain diet when you’re back eating normally again?

    1. Chris Avatar

      Hola Stephanie. Good to hear from you! And good question. Actually impossible question! Finding the right diet is tricky, obviously. When I’m back eating “normally” after fasting I try to eat only when hungry (normally twice a day), never snack (which becomes easier to do after fasting and you’ve kicked your old eating routine), and avoid highly processed food as much as possible. Everyone’s got their own take and opinions on what foods to eat exactly, but these general rules seem to be strongly backed up by science and many, many studies.

      1. mishal Avatar

        hey! if i go on a 20 day water fast and after eat at at my maintenance calorie level, will i regain any weight back? or is there a way to keel it off?
        amazing blog by the way!

        1. Chris Avatar

          Thanks Mishal. The theory is that if you do a 20-day (!!!) fast your body’s “set weight” will recalibrate to a lower level, so when you return to eating at a maintenance calorie level (and assuming those calories aren’t full of processed carbs), the weight you burn off will stay off. The Obesity Code does a good job of explaining the mechanisms behind this in a way I found to be easy to understand. All the best!

          1. Meg Avatar

            Hey there, huge fan of Dr Fung. And truly appreciated this post. I’ve done a “cancer fast” every year for the last few years. I was diagnosed with BC a few months ago. I’m about to start chemo and have been interested in fasting to help with killing cancer cells and help with side effects. Have you come across anything in your reading/research?


          2. Chris Avatar

            Hey Meg. Sorry, no. And more sorry about your diagnosis. I’d be curious to know what you find. Whether or not fasting plays a role or not, here’s to you beating your cancer.

      2. sana Avatar

        hi Chris i just read your post. I was wondering how to do water fast? like do you drink just water? if yes how much and like every hour a glass or every two hour? and for vitamins and electrolytes what can be done?
        I currently weigh 220 pounds age 25 height 5’4 and planning to lose at least 50 pounds. I read somewhere you can lose that much by water fast but i have no idea how to do that searched online but just found out like we need to drink at least like 2-3 litres of water a day. but didn’t mention how and when in the day. also do i need to do any exercise?

        1. Chris Avatar

          Hi Sana. You don’t actually have to drink that much water while water fasting. More than usual to replace the hydration you’d get from your food, but too much can be just as bad for you as too little. Your body’s pretty good at telling you when it’s thirsty as long as you listen. Just remember to add some salts to replace what you lose in your sweat. Whether you exercise or not depends on how you feel. Good luck with your continued research on fasting (a good idea given your admirable goals!) and good luck with your fasting.

          1. J Avatar

            Aloha Chris. Thanks for this blog. It was helpful. Basically we drink water whenever we feel thirsty? Would the general rule of drink half your body weight in oz be Sufficient enough? can I add lemon water? Should I fast 1x/month?

          2. Chris Avatar

            Hey J. You’re Hawaiian? Lucky you. I’m not aware of half your body weight in oz, but if it’s true you might have to drink more to compensate for not getting any hydration via the food you normally eat. I’m a big fan of adding lemon juice when I fast. As for how often to fast, I’m sorry if it’s obvious but it depends on how long you go and how you feel. Some do a weekly 1 or 2-day fast. Some one 7-day fast once a year. Some, with medical supervision, fast 5 days on, 5 days off for months. Try it, see how you feel, and go from there. Aloha!

        2. Grace Goode Avatar
          Grace Goode

          Hello Chris, I really appreciate all the information you’ve given. You said that after about 2 days the sugar is out of your body and you start burning fat. If you fast the 2 days to detox all the sugar can you end the fast but just eat no sugar? Will it still cause your body to start burning fat?

          1. Danial Avatar

            I think you looking for keto diet

      3. Bhav Avatar

        Hi Chris, is vomiting during water fast normal? I was 38 hrs into my fast and i threw up twice within 2 hrs before I decided to end my fast. Also very uncomfortably my throat was burning after I vomited as if i threw up my stomach acid. Is this normal? I did 16 and 24hrs fasts before i was doing perfectly alright please write back I really want to continue doing it but it got a little scary there… hope to hear back soon thanks all the info!

        1. Chris Avatar

          Hi Bhav. Others have commented and messaged me about vomiting, but I haven’t looked into the causes or treatment other than what you did: eat. (Good idea!) So I have nothing to suggest, sorry. But if you or anyone else finds anything, please share!

    2. lalita Avatar

      Thanks for the awesome info chris!

      1. Chris Avatar

        I’m glad you appreciated the post, Lalita. Thanks for the thanks!

        1. Rebbs Avatar

          I’ve been fasting for 2 days and only lost .2 kilos is there another issue ?

          1. Chris Avatar

            Hi Rebbs. Unlikely. You’re staying well-hydrated, I imagine? Just be sure not to drink too much. As a rule of thumb, your pee shouldn’t be clear or too dark.

    3. Tori Smith Avatar
      Tori Smith

      Quick question- Is a gallon of water a day enough water for me not to get dehydrated?

      1. Chris Avatar

        Hi Tori. A simple way to gauge how much water to drink is with the color of your urine. If it’s clear, you’re drinking too much water and counterproductively dehydrating yourself by washing out electrolytes. If it’s dark and stinky, drink more.

    4. joel schlecht Avatar
      joel schlecht

      Hi, I know this is too late for you but other people read these. I’ve done a 25 day fast a few years ago and several smaller ones after. This is what I found during and after that. The ghrelen hunger almost completely good away after maybe a week or so. This makes it much easier to eat less afterwards. Remember that even fat cells and lugging extra weight around burns calories so you will need less calories than you did before for maintenance. Also, your body may be in the mode to conserve energy like being less fidgity without you even noticing. So, getting back into the swing of being active again is important because you will get sluggish near the end. On a fast this long, you may be susceptible to refeeding syndrome. Your muscles use calcium, sodium, magnesium, and potassium every time they move. You get sluggish to compensate. When you start to refeed, your dormant digestive system goes into action and that’s a lot of muscle. That takes away whatever electrolytes you have left away from your heart muscle and it’s possible to have a heart attack. So, make sure you have a good supply of these minerals every day. Especially potassium. Potassium pills are by law a of very low concentration so you have to take a lot of them. So take them throughout the day if you don’t want to swallow a bunch of pills at once (at least 10 if not more check out daily requirements vs supplement content).

  2. Lana Gunia Avatar
    Lana Gunia

    All those question and answer about water fasting are really useful also the tips you show here are incredible for water fasting. I have the same question like Stephanie, May I easily get back to normal water again?

    1. Chris Avatar

      You mean easily get back to normal eating again, right? (Cuz I don’t know what “normal water” means.)

      On your first post-fast meal, start with something light, like a salad with some oils and nuts (no heavy carbs). See how that goes. If you’re still hungry, eat more. You’ve earned it!

      Then, when you get back to eating day-in and day-out, try to keep yourself from falling back in the unhealthy hunger cycles you might have had beforehand (3+ meals a day, tons of snacks, non-stop cravings for processed carbs). Skip meals here and there. Or even full days after huge meals or big nights out. Eat as much as you feel when you eat, but eat less and restrict what you eat (as much as possible) to unprocessed foods.

  3. Jody Maroccia Avatar
    Jody Maroccia

    I have not done a fast in long time. I did a 3 day fast long ago and only had water. I had all the symptoms you described, but I did not add any fruit to my water or have green tea nor I think had black coffee either. I am going to try it for 7 days this time, with all of your suggestions. Thank you so much for all of this information! 🙂 One last thing, a question… So you are saying after say day 4 or 5 I will get very hungry and that’s when I know I need to break the fast?

    1. Chris Avatar

      Glad to have helped Jody! What I meant to say was not that you’ll get very hungry after day 4 or 5, but that you can expect to start feeling very hungry—or maybe not “hungry” but eager to put your teeth to use again—towards the end of your fast. Once the end is in sight, you start fantasizing about that first bite. (At least from my experience and that of people I’ve talked to.)

    2. Akshaya Rhual Avatar
      Akshaya Rhual

      Did you lose weight after 3 day water fasting..if yes,how much?!…And what are the after effects..did you regain weight by going back to normal eating..And what sort of food you ate

      1. Chris Avatar

        Hi Akshaya. You’ll find the answer under the question, “Will I lose tons of weight if I do a 3, 5, or 7 day fast?”

    3. joel schlecht Avatar
      joel schlecht

      The “hunger” usually dosent return until I think your body thinks it’s starving to death. In day 24 I got super hungry like I did on day 2 or 3. I could talk myself into one more day but then I thought it must be getting dangerous for me and the hunger was almost unbearable. I think this was triggered by some food smell and my body said “you have to get that any way you can!”. After week two, I thought I could go for a full 40 days until that point. Remember, it’s not some sort of challenge, it’s for your health and when it’s no longer healthy, you have to stop so listen to your body.

  4. Mariana Avatar

    Hello !! First of all I want to congratulate you for your amazing blog. I haven’t tried water fasting, but I have been on intermittent fasting for a while and I have noticed a lot of differences. I dont feel hungry all the time and my focus and concentration got better. I usually drink coffee and a lot of water until my first meal of the day, that will be lunch time around 2pm. Dinner usually is around 8/9pm. So I try to do a 17-18h fasting. However I have some questions. I usually take some supplements in the morning with a big glass of water with lemon juice (vitamin C and b carotene) and I chew 1 or 2 sugar free gum . Should I do this while I am fasting ? Thank you so much !

    1. Chris Avatar

      That’s great, Mariana. I also fasted intermittently like you for quite a while (with the same benefits) before I tried my first multiple day fast. It certainly made it easier. I drink water with lemon juice every morning too!
      Regarding your question, supplements are fine, but stay away from all sweeteners. They’ll play games with your insulin and other hormones even though they’re calorie free. Is there such thing as unsweetened chewing gum? (Or is that just called “rubber”?) Check out my fasting FAQ for more tips.

      1. Cassandra Avatar

        Hi Chris, just reading thru comments. Blog is great. Been fasting for years myself. What you said about spring cleaning and feeling energized are really true. I usually go about 10 days in the winter. Re the gum chewing vitamin supplement to replace lost vitamins. I suspect that would sabotage the fast because I could imagine the the act of chewing triggers digestive hormones and the subsequent production of stomach/digestive fluids. Your thoughts on this?

        1. Chris Avatar

          Thanks Cassandra. I could imagine that gum chewing might have some minor effects on fasting, but my simple (and maybe simple-minded) philosophy is that as long as you’re severely restricting calories for a certain number of days, you’re doing your body good. Better make those concessions than give up and get back to eating. And Viktor Longo’s studies (even the 5:2 diet guy, too) seem to show that having some food while “fasting” still has significant benefits.

      2. Nicoleta Viulet Avatar
        Nicoleta Viulet

        Hi Chris…There is Xylitol Chewing gum which I understand is good for your gums. Anyway we need more people like you to share from their experience. Thank you for this post. But I would say like with everything else…all in moderation!

        1. Chris Avatar

          All in moderation, especially moderation, right Nicoleta?

          Thanks for the tip on Xylitol gum.

      3. Rab Avatar

        Hello, can you smoke cannabis for sleep?

        1. Chris Avatar

          Hi! Haven’t looked into it. No calories in it, right?

  5. John Avatar

    Great tips, specially for a health trend that’s become very popular as of late. Very funny too. I try fasting a few times during the month, I don’t do it every day, but I gotta say, it’s actually easier than I thought. When I commit to do it for 1 or 2 weeks consecutively, the first day is the hardest, since you adjust. Then it’s pretty much a breeze. I don’t have the sleep problem, on the contrary, it helps me sleep since I go to bed early to avoid feeling hunger.

    1. Chris Avatar

      Thanks John. Sounds like you and me have similar fasting routines and react the same way to it—sleeping extra well when fasting. I suspect it’s because the sleep benefits of our bodies not having to spend energy digesting food outweigh the extra alertness that keeps some people up.

    2. Emily L Avatar
      Emily L

      Hi, i don’t know if you are still on this blog or answer questions but I was wondering how often to do a water fast? This will be my first one and I want to go for at least 3 or 4 days. If I love it I just wanted to know how often to do it and whats safe for my body. Thank you for this blog it was amazing and informative.

      1. Chris Avatar

        Hi Emily. Kudos for your enthusiasm and optimism. Before worrying about how often to fast, try doing your first one. See how you feel. That will most likely answer your question for you.

  6. Jennifer Avatar

    I believe you are not suppose to add any fruit to your water as the point is to use the reserves of nutrients stored in your cells and not have more digestion of nutrients coming in….

    1. Chris Avatar

      Yeah, I’m with you on the point of fasting, Jennifer. I’m not so sure there are many calories in a fruit-infused water, though. Seeing as Valter Longo’s been able to more-or-less replicate the fasting benefits with a fasting-mimicking-diet of a few hundred calories a day, I doubt infused water makes much of a difference. Buy, hey, good on ya if you feel a pure water fast is best for you!

    2. Tessa Avatar


      Thank you so much for this article. I’m starting a water fast tomorrow and am interested in podcasts and books on fasting. Between Dr. Fung’s two books, The Complete Guide to Fasting and The Obesity Code, which would you recommend as a first read?

      1. Chris Avatar

        Hi Tessa. Good question. It depends on your nutritional knowledge. If you’re just getting started, go for The Obesity Code. It’ll give you a good general understanding of nutrition and what contributes to making people fat/skinny. Then, if you like his writing style, get The Complete Guide to Fasting for more detail on fasting, specifically.

  7. Rachel Avatar

    Why is diet coke or “zero calorie crap” not allowed? What about sparkling water? or anything sweetened with Stevia?

    1. Chris Avatar

      Hey Rachel. Sparkling water’s totally fine. The problem with any zero-calorie sweetener is that even though they are calorie-free they still stimulate insulin and hunger responses. Try adding lemon or spices like cinnamon or mint to flavor your water instead, or infuse it with orange slices, berries, or cucumber.

      1. Rachel Cox Avatar
        Rachel Cox

        They promote insulin spikes in mice, not humans in all studies done. It’s been pretty much debunked.

        1. Chris Avatar

          Indeed one of the most cited studies arguing sweetners’ effects on insulin resistance is a 2014 one on mice, but there are others like this one, published Sep 2018, done on humans with the same result.

          When it comes to nutrition, there’ll always be arguments (and studies) for and against anything because it’s so complex and long-term. If artificial sweeteners make it easier for you to fast and you enjoy clear health benefits as a result, by all means keep it up!

          1. Michael Mallett Avatar
            Michael Mallett

            You didn’t provide the study

          2. Chris Avatar

            Hi Michael. The link is there but the text wan’t properly formatted to make it clear it was clickable. I’ve fixed the formatting now. Thanks for pointing that out.

          3. Todd Evans Avatar
            Todd Evans

            Truly, the argument for or against artificial sweeteners is a personal one. What causes insulin response for one person, might not for another. I’ve been keto for 10 months (68 pounds lost, whoo hoo) and have just begun to start intermittent and extended fasting. In my OWN personal experience, I’ve found that my weight loss was more consistent when using monk fruit blend (erythritol), as my go to sweetener. Sucralose and allulose seem to slow the loss down. I prefer to stay away from aspartame all together because well…it’s poison. Stevia has been good to me, but I don’t much care for the taste.

            Best bet, in planning for an extended fast, where you NEED your sweeteners is to get a blood glucose meter, and simply use trial and error to find which ones, if any, effect your blood sugar. Eat a spoonful of one each morning and check your blood an hour or 2 later. You’ll be able to eliminate the ones that will cause insulin response.

          4. Chris Avatar

            Way to go, Todd (68lb!) and thanks for the interesting insight on sweeteners. Have you met people who have reacted differently to certain sweeteners than you?

      2. Jamie Ferry Avatar
        Jamie Ferry

        Lemon and citrus fruits have fructose in them that breaks the fast.

  8. Ann Avatar

    You didn’t mention anything about perscription or OTC medications. I take an allergy, blood pressure and baby aspirin pill daily

    1. Chris Avatar

      Hey Ann. Under “Why shouldn’t I fast?” I had written that anyone taking medication should consult with their doctor first, but I’ve added the clarification that this means both prescription or OTC based on your input. Thanks.

      On the topic baby aspirin, coincidentally I recently listened to a podcast episode in which a doctor I trust, Peter Attia, mentioned that he dove into the research on it after a client of his asked him about it and discovered there was little, if any, research backing it. I don’t remember what his specific conclusion was, but since you’re taking baby aspirin it might be worth a listen. Here’s the episode: Kevin Rose Podcast Ep. 31.

  9. Zaid Avatar

    I’m just wandering how much water and what if I feel like I’m drinking too little water I tried it and ended up only drinking 3 cups a day. I’m also wandering if i should be worried that my urine is a dark orange color regardless if im water fasting or not.

    1. Chris Avatar

      Hey Zaid. 3 cups of water is almost certainly not enough. A simple way to know if you’re drinking enough water is if your urine is clear or not. If it’s dark, you should drink more. From my experience, you really have to force yourself to drink even more than you feel like you should when water fasting. And try putting a dash of sea salt in your water, which seems to help keep the water from going right through you.

      1. Pascal Avatar

        Hello Chris,

        first of all, great post and sorry for such a late reply, but i didn’t find it sooner :P.
        I’ll have to disagree on that drinking part tho. Drinking too much doesn’t help at all (maybe with cravings when you flood your stomach?), but all it does is flushing out the electrolytes you desperately need, especially when fasting. Also, dark urine is absolutely not bad, it is a sign that you are flushing out toxins etc. you don’t need in your body and if you dilute them with so much water that it becomes clear, thats certainly a sign you drink too much.

        I don’t want to encourage anyone to fast dry without having proper experience and having done proper research, because this can definitly swing the wrong way. I have had some experience with fasting for days without food AND water and i can promise you, i am still alive 🙂 I actually felt more hydrated during that time, than ever before, which got backed up by many other people who dryfast, and since then i am convinced drinking too much water doesn’t do you any good and actually makes you feel more dehydrated, due to the aforementioned flushing out of electrolyters.

        Also i wish you had put a little more emphasis on taking the electrolytes, because they can really make or break a fast and everyone should drink saltwater during their waterfast, because again, otherwise you flush out your electrolytes and you feel weak and bad, since your body basically can’t use the energy as well.
        Again, great post, i am always glad when someone tries to reach out to people about fasting!! Especially with such a great post!

        1. Chris Avatar

          Hello Pascal,

          Thanks for this perspective. You didn’t convince me to ever try fully dry fasting but I have to say I’m swayed by your rationale on not drinking too much plain water, and adding electrolytes when you do. Next fast I’ll give it a go and when I get the chance I’ll update this post with your advice.

          1. Angela Avatar

            What about a 2 day fast…is it worthwhile

    2. Annie Avatar

      If you’re urine is orange you should check with a doctor

  10. Russell Adrian Avatar
    Russell Adrian

    Thanks for all the info. What about supplementing with Sodium, Potassium and Magnesium?

    1. Chris Avatar

      Hey Russell. I don’t know the science behind each specific mineral, but in general it does help keep you hydrated and replenish minerals lost through sweat to add some sea salts to your water. Sea salt contains sodium, potassium, and a bit o magnesium.

  11. aa Avatar

    What about working out? Should you avoid weight lifting ? and cardio?

    1. Chris Avatar

      Good question. Technically, you can exercise as much as you want. Here are all the technical details. Practically, and from my experience, it’s not so easy. When I try exercising after 2 or more days of fasting, I get lightheaded quickly and don’t have the same stamina, so I tend to take it easy. I consider fasting itself to be a good enough workout.

  12. Sydney Wiedenhoeft Avatar
    Sydney Wiedenhoeft

    Is it ok to add BCAA’s to water while fasting? I also have a “coffee creamer” BCAA that has no calories.

    1. Chris Avatar

      Hi Sydney. What are you taking BCAAs for? It seems (from this study for example) that taking BCAAs stimulates an insulin response, so in general it’s probably not advisable, but it really depends on what the reason you’re taking BCAAs for is in the first place.

      1. Stacey Avatar

        Fasting (prolonged total nutrient deprivation) downregulates mTOR (a kind of metabolic master switch) which in turn kickstarts cellular cleansing (autophagy) and also upregulates the production of adrenaline, growth hormone etc. Taking BCAAs sends the “incoming nutrients!” signal thereby re-staring mTOR, provoking an insulin response, and shutting down autophagy, and the production of growth hormone, and all the other amazing metabolic benefits of fasting. So basically BCAAs (or any proteins carbs/sugars) undermine your fasting pretty significantly. Same with bone broth if it has lots of protein in it and you drink lots of it. I stick with warm sea salted water with potassium and magnesium (many commercial electrolyte powders have either glucose or artificial sweeteners which undermine fasting benefits, but make more sense if you’re taking them to rehydrate after GI upset or intense exercise). Here’s Dr. Fung on BCAAs: https://idmprogram.com/fasting-and-autophagy-fasting-25/ good luck and happy fasting! Oh, and I also found that if I’m doing a 5+ day fast I have to start the salt and electrolytes within the first 48 hours, because I sweat so much while exercising (which for me performance improves noticeably during fasts) and it’s too late to start taking salt on day 3-4 – everything gets out of whack and I feel weak and shitty. Made that mistake once and my BG dropped to 43 (ketones 4.6) but I felt so shaky and anxious I decided to end the fast a little early just in case. SeaSalt+K+Mg in the first 48hrs and I feel perfecto throughout the fast.

        1. Chris Avatar

          Super helpful, Stacey! I especially like your advice to start adding the minerals to your water as a preventative measure rather than a reactive one.
          I’m also interested to hear in what way your exercise performance improves noticeably during fasts. Strength? Endurance?

  13. Scott Avatar

    Hi Chris, I’m 3-1/2 days in and feel good, no hunger issues, a couple of minor headaches and I feel good about process. My question is I’ve had the runs since I started and I wonder how to stop them? I saw a couple of comments above about sea salt, how much and how frequently?

    1. Chris Avatar

      Hi Scott, A lot of other people seem to have the same issue. I haven’t personally, so I looked around online. I didn’t find any scientific info, just anecdotal tips like this and this where the consensus seems to be it’s normal and if you feel fine don’t worry, but if you feel lightheaded or otherwise dehydrated take some electrolyte powders or drink some bone broth. That or eat soaked chia seeds for some fiber… or simply start eating again.

    2. Andrew Avatar


      You’ll get the runs the first 3 – 4 days to a week as your body essentially cleanses (at least that’s what I call it) your intestines. Mine stopped by day 4. Just be prepared and always head to the restroom just in case. You can also suffer from carb withdrawal sickness (flu like symptoms) the first week or so.

      13 days into a 40 day fast, should have done this a decade ago, could have been a trend setter! Down 20 lbs and no energy problems. Electreolytes and coffee definitely help 🙂

      The strange thing is… despite my desire to eat, after the first three days I haven’t really been hungry outside of my normal eating times.

      1. Skye Avatar

        Hi Andrew,
        Just wondered if you made it to day 40 of your fast and your final results? Did you gain back any of the weight after you went back to eating? Also, what did you eat After you completed the fast (for the first few days, to week)? Did you know When to stop fasting, or you were determined to make it to 40? Would love to hear an update!

    3. Emily A Boronkay Avatar
      Emily A Boronkay

      Apple coder vinegar is really helpful. Plus it will help maintain healthy gut biome.
      That’s supposed to be why it works for diarrhea.

  14. Anthony Gregorio Avatar
    Anthony Gregorio

    Hi Chris. I’ve successfully made it thru a 12 day juicing cleanse before and when coming out of it I ate the wrong foods and ended up with a heavily debilitating case of internal hemorrhoids from explosive diarrhea. Yuck lol. What do u suggest to come out of this fast in a way where my body can adjust to a ketogenic lifestyle.

    1. Chris Avatar

      Ooof, that’s quite the vivid description Anthony! Sorry to hear you had to deal with that shit (no pun intended). What are the “wrong foods” that you ate? Coming out of a fast it’s safest to resist the urge to make up for all the food you didn’t eat in one go. Start with something like a salad with some nuts and olive oil, give your body time to react to it, them ramp up your eating back up to whatever diet you want from there.

      FYI – You may find this podcast about juice cleanses and whether or not they’re effective.

  15. Anna Avatar

    Hello. I started my fast to clear up my acne and lose some pounds. I’ve lost 21 pounds total. Although for the last 4 days I have maintained the same weight and my acne is still here on day 17. I’m not sure if it’s time to throw in the towel, what do you think?‍♀️

    1. Chris Avatar

      Hey Anna. 17 days is a lot, so if you feel like it’s time to give in, maybe you should. You can always do more fasts later. When you make healthier eating habits part of your lifestyle and not a one-time thing you’ll start to really reap the most important long-term benefits.

    2. Moa Ramini Avatar
      Moa Ramini

      The acne will only disappear if you cut diary products for at least one month, and cut milk totaly. You will then never have the acne issues again. Trust me. Had this problem since i was 10 years old and tried everything, until i stopped consuming milk and dairy products. You can replace it with oatmilk, ricemilk, almond milk and so on.

      1. Hellen Siemens Avatar
        Hellen Siemens

        My daughter in law had the same experience. After trying everything available with no result she quit dairy and her skin cleared up beautifully

    3. Jaclyn Avatar

      Hi Anna. If you are fasting to help clear acne, make sure you drink enough water. And use a good acne face wash. I know this is a very late response, I apologize for that.

  16. queralt Avatar

    teo questions: can i keep on doing sport, still study while im doing this water fast? whats the ideal first time to fast on the first time? Thanks by the way all the other tips where useful!!

    1. Chris Avatar

      Hey queralt – On sports there seems to be divided opinion. Some say you should let your body rest and regenerate without the extra stress. Others say you fasting’s the best time to exercise. Until there’s more certainty, I’d say do what feels right for you. And on when’s the ideal first time, I’d say to try when you you have a few days available that aren’t too busy or stressful and aren’t going to be around people who’ll try to convince you to eat. Starting on a Thursday evening then stopping on a Sunday evening is a good bet. Keep your mind off food by planning some fun things to do over the weekend.

  17. Sissi Avatar

    Hello 🙂 I keep hearing and reading that most seem to have more energy when fasting. I was feeling pretty good days 5-10. Now, on day 11, I’m just so tired even though my sleep has finally returned to normal. I salt my water, take magnesium and potassium, and have a cup or two of green tea daily. I also drink about 2 liters of water. Not hungry, just so freakin tired. Like, if I close my eyes for a few seconds, I will fall asleep, haha 🙂 I haven’t heard or read anywhere that this should be a sign to stop and I definitely don’t want to stop. Any suggestions? PS – You are amazing to take the time to help people like this!

    1. Chris Avatar

      Hello Sissi, and thanks for the comment! I’m sorry to say that I have no experience with your situation. Could it be that you’re still sleep deprived from what you seem to imply were abnormal sleeps from your first days of fasting? Or could it be dehydration—do you have clear urine or is it pretty smelly and dark? Two liters isn’t actually that much when you’re not eating anything at all. If it’s none of those things, be safe and eat. 10+ days is a long time to fast already.

      1. Stephen Brickwood Avatar
        Stephen Brickwood

        Chris, I was like you, never missed 4 meals a day in my life. A good friend was having her foot ‘cut off’, because of sugar diabetes, she can not change her diet. Other friends have died. SO I went looking for something to control my hunger and increasing weight. Bingo, I find Dr Fung, and after several attempts I did a 22 day water only fast Jan 2019, I get bloody minded, I think that the body supplies all that you need, except for water. The first 3 days were hard, but then much easier. I am doing a water only fast now and it does get easier and after 7 days today, I feel brilliant, I just take a day at a time and will continue this fast for a bit longer. I am 70 and can not believe how clever this is. The industrial food, diet, gyms, pharmaceutical will not make money on this. NOBODY MAKES MONEY on this. Thank you Chris. Good luck Sissi.

        1. Chris Avatar

          Thanks Sissi. Hopefully your experiences and successes at fasting will motivate your friends to help themselves and do the same.

  18. Michael Avatar

    Will weight loss results be different (less) if I am already in ketosis before I begin my fast?

    1. Chris Avatar

      Not really. If your metabolism is running a bit faster from your ketogenic diet already, you’ll be a step ahead towards having more longer-term benefits and have an easier time fasting, but nothing big enough to be able to see any notable fat loss differences over a short period of time compared to someone going into the fast on a non-keto diet.

      1. Hannah Avatar

        Hey, I’m trying to do a 20 day water fast right now and I’m on day 4 right now. I was wondering if you will lose more weight from a water fast if you are already 200+ pounds? I also chew gum twice a day that has no sugar in it, is that okay?

        1. Chris Avatar

          Hey Hannah. If sugar-free gum keeps you going strong through your fast, keep doing it. On your first question, I suppose people who weigh 200+ pounds might have a slightly higher caloric running rate to keep their extra mass energized (this overview has links to studies that seem to confirm that), so the deficit and thus fat burning will be higher for them when fasting. But it wouldn’t be order of magnitudes faster. It’s inevitable that the more fat you have, the longer it will take to lose it.

  19. Dee Avatar

    Huge thank you!! Amazing article and it’s empowered me to keep going on my first 7 day water fast. I’m on day four. You’re awesome

    1. Chris Avatar

      Way to go Dee! It’s 3 days after you comment, so Day 7 of your fast, so… bon appetit!

  20. Maxo Avatar

    This is really valuable content. I thought I would pass a note to thank-you for posting! You’ve gained a new subscriber.

    1. Chris Avatar

      Thanks for the thanks Maxo. I appreciate it.

  21. Prakashraj Avatar

    Hi thank you for this useful material on water fasting. I am planning to go on a water fast for 21 days. I have no health problems and not under any medications. I am 40 years old. I have two doubts
    1. During the first few days can I drink triphala to get my bowels cleared.
    2. Breaking fasting. If I break carefully as advised still will I have any risks in getting back to normal diet. Will my digestive system get back to 100 percent? (Some posts I read are scary that’s why I ask.)

    1. Chris Avatar

      Thanks for the comment and questions Prakashraj. A 21-day fast and your question go well beyond my knowledge and experience, so all I can suggest is the following: I haven’t read anything about needing to clear your bowels—your body should do that for you without issue unless I’m missing something. As for your digestive system, are you referring to your gut bacteria? After 21 days I suppose some good and bad bacteria will die and the whole ecosystem will need to be replenished. It’s probably a good idea and can’t hurt to eat some fermented foods post fast to help regenerate.

  22. skye Avatar

    i m on my 3rd day of fasting, i can controll my hunger but i cant sleep properly in night and have constant headache (minor) and started to feel nausea after 2nd day (may be i should drink less water), i was hoping to find some tips about headaches. only thing that keeps me going is ‘4th day’ peole says u get euphoria state, i wanna feel that.

    1. Chris Avatar

      Hi Skye. As you probably found on other sites, the headaches are probably due to low blood sugar. For future fasts, it can help to eat a low-carb diet for the days or weeks leading up to it to ease your body’s transition from relying on sugar from your diet as a source to creating sugars from the fat reserves on your body.

      1. Bart Avatar

        From my experience, if you’re going cold turkey on sugar and other carbs – and caffeine! – you’ll get the migraine-like headaches and feel deflated for the first 3 or 4 days. It’s temporary, it goes away, and if you go beyond 5 days with your fast you’ll actually feel clear-headed and generally great…Chris – any “fasting kits” that you know of from the health food stores with mineral supplements? …Thanks for the write-up!…

        1. Chris Avatar

          Good to know, Bart. Thanks. After you’re done fasting, do you eventually get back on the sugar and caffeine horse, or do feel less of an urge and consume it?

          As for fasting kits, no sorry, I don’t know. I find dehydration tablets from the pharmacy help, since preventing dehydration is exactly why I’m taking the stuff. And then good-quality bone broth if I really need it.

    2. Jaclyn Avatar

      Headaches are a symptom of hyponatrema (drinking too much water)

  23. Prince Avatar

    Hello, Your post is amazing and i feel it very helpful in doing my water fast but when i started water fasting i feel pain in my stomach at my lever side on 2nd day and i am aiming for 2week fast. I have fatty liver should i drop fasting or what i do please suggest me.

    1. Chris Avatar

      Hi Prince, I wish I could help, but your questions go way beyond my (un-)qualifications. If you’re unable to seek in-person expert advice, the safest thing would be to take it easy and slowly work your way to really long fasts. For me, getting accustomed to having only 2 meals a day (and zero snacks) helped a lot. So did getting rid of sugar. If I’d gone straight into fasting from bad eating habits, my body for sure would have rebelled.

  24. Prince Avatar

    I also facing some gastric issues what i do while fasting

  25. Ben Avatar

    Day 1 almost under my belt. 19 more to go. Looking forward to seeing so many good results. Great information here & comments. Thanks!

    1. Chris Avatar

      All right! One day at a time. All the best, Ben!

  26. atilla Avatar

    Hi. Is it okay to eat vegetables and a very low amount of calories from fruit or meat so I can remain in ketosis but get some bowel movements (I am worried it not being emptied for several days, and there is no sign that I will poop in the near future) and get some nutrients?

    My main reason for fasting is weight loss, and since I am now on day 8 of my fast of water, salts and vitamin tablets, I’m sure a huge amount of detoxing has already been done. So as long as I remain in ketosis, I see no reason to eat a little bit of fruits and veggies.

    1. Chris Avatar

      Hey Atilla, Yeah, if you want to remain in ketosis, feel free to go nuts on veggies and oil… and nuts! Fruit is a different story though—too much sugar—so avoid it. Check out Valter Longo’s work on fasting mimicking diets; he’s found that some diets with a limited number of calories, mostly from veggies, can replicate the long-term benefits of fasting.

  27. Marla Avatar

    Hello there! I am fasting to lose much needed weight. I plan on doing a 5.5 day fast with 1.5 day refeed each and every week. I will repeat this over the course of 4-5 weeks. Would this be a waste of time or should I do an extended fast to lost weight faster?

    1. Chris Avatar

      Hey Marla. You should consult with a doctor on such a big program. In general, do whatever feels good for you. People have great weight-loss success with even less severe restrictions than you’re doing (5 on, 2 off). What’s important is keeping it up and breaking that addiction to food.

      1. Marla Avatar

        Thank you so much for your advice, I think I will definitely try that out!

  28. Kat Avatar

    Just wanted to congratulate you on this amazing article. Not only super insightful and helpful but also fun to read. Way to go! One unconventional idea a month it is…. Subscribed.

    1. Chris Avatar

      An honor to have you on board, Kat! Let me know if you have any fun unconventional ideas of your own that I might be able to share with the rest of us in a future monthly update.

  29. Lynda Huffman Avatar
    Lynda Huffman

    I see you suggest putting a ‘dash’ of sea salt in your water so the water does not run right thru you. When water fasting how often or how many times a day do you do this ?

    1. Chris Avatar

      Hey Lynda. I do it with just about every glass of water I have while fasting. I do first thing in the morning when not fasting too. As for how frequently I drink water while fasting, I don’t keep track but it’s a lot. For me, the biggest challenge is staying hydrated. All the best.

      1. Skye Avatar

        You mentioned a ‘dash of sea salt’ in all the water you drink. Will all that sodium make you keep water weight on? Also, regarding salt – would pink himalayan salt have a same/different effect than sea salt? The taste of salt in water makes me gag I think it tastes awful – but I know I need the sodium. I tried a 2.5 day fast recently (I wanted to make it a 7 day one but caved), and noticed my muscles felt like they were getting weak – felt strange, I was concerned – is this normal? Do your muscles atrophy when fasting? Just wondering what I can do in place of the salt (if anything)? Would those electrolytes you mentioned in your article work equally as well for sodium? Could you take those electrolytes daily (or only so often)? Thank you so much for this great article and advice!

        1. Chris Avatar

          Wow, that’s a flurry of questions Skye, some of which are beyond my area of non-existant expertise. My muscles sometimes feel weak when fasting, too. That’s normal. And from my experience the electrolytes helped a bit. You might want to try bone broth too, if you feel really weak. Your muscles may atrophy a bit (but not much until you run out of fat). That definitely shouldn’t be a reason not to fast because once you get back to eating they’ll regenerate better than ever.

  30. Wayne Avatar

    I did the 3 day water fast and my wife enticed me with my favourite buttertart. I almost ate the bag that it came in. Now I feel pain 30min after I eat or drink anything other than water. Thoughts?

    1. Chris Avatar

      Hi Wayne. Sorry, but I don’t have any quick fix ideas for you. Thank you though for making me chuckle imagining you seeing and devouring butter tarts after your 3-day fast.

  31. Selina Avatar

    I recommend when you break your fast to eat a date as it’s healthy and natural for your body. Is nothing new fasting anyway and it’s not to loose weight but to clean your body and to discipline yourself

    1. Chris Avatar

      Thanks Selina. I’ll try eating a date (just one?) after my next fast.

  32. Diana Avatar

    Hey Chris, great article, thank you for all your efforts! I’m a breastfeeding 36yo mama of 8, on an undetermined length fast and about 40 hours in. My baby is almost 2, so we’re open to weaning if my milk dries up, but I’ve read a bit about it and many mamas claim it doesn’t, and some claim their supply even increases so it will be interesting to see how it goes! My oldest four are all gone camping with youth groups for a few more days so I thought it would be interesting to see if I could at the very least last til they got back home. I only have the last stubborn 15lbs to lose and want to see how long I can hack this. Next, I have to look up the effects on kidneys because though my urine is completely clear I woke with kidney pain today. It’s a hereditary issue though. I wonder if this will help that, also? (In the long run). Anyway, thanks for all the great info and support! I’ll let you know how it goes if you’re interested 🙂

    1. Chris Avatar

      Hey Diana, Super interesting. To cover my own butt, I do want to reiterate that fasting’s not recommended for pregnant or nursing mothers, but it seems like you’re being extra careful and your kid’s older. Please do keep us posted on what happens.

      1. Karen E Kain Avatar
        Karen E Kain

        Hey Diana,
        I too am water fasting and nursing an 18 month old. I am at 66 hours and have not lost my supply. How long were you able to go? Have you changed some stinky diapers? My lo had bananas a few days while I was fasting and I wasn’t sure if the diapers were from those or junk being passed in my milk.
        Thanks for the tips in your article Chris.

    2. jamie Avatar

      also a breastfeeding parent, and milk still going strong at day 19 of fast. i left a more extensive comment below, maybe search for breastmilk in the page to more easily find it.

  33. Nathan Avatar

    Hi Chris, this was a fantastic read and just what i needed as i’m currently on day 2 of my first ever fast and it’s getting hard, i have one question though with regards to diet cola, i had a can of it this morning and then read this and realised i wasn’t allowed it.

    There is a lot conflicting information on it raising insulin and not but it really helped my headache and craving to break the fast, have i undone my hard work so far or should i just forget about it and carry on?

    1. Chris Avatar

      Hi Nathan. In the future I’d recommend some electrolytes in your water to help with headaches. I feel in soda water they feel even more “substantial.” Don’t worry too much about your one can; it’s not ideal but it won’t completely erase your two previous days. And if it’s what you need, whatever. It’s huge progress anyway. Next time it’ll probably be easier and you won’t need the coke.

  34. Sherri Avatar

    Hi. I just finished a 5 day water fast after a month of cutting out caffeine, sugar, processed carbs and alcohol. I’ve done many cleanses over 20 to amazing results, but always wanted to water fast. I followed good guidelines and had challenging, but beneficial results. The issue is coming out of the fast. First day I did veg juice, low carb smoothie and soup broth. Yum. Day 2, same but I craved a salad, but nothing is satisfying! My mouth feels chalky and my taste buds seem dormant! I usually love my salads and miso soup. Also, the other foods were disappointing even my usual healthy smoothie. Thoughts?

    1. Sherri Avatar

      *20 years*

    2. Chris Avatar

      Hi Sherri.

      My experiences coming out of a fast have always been the exact opposite—my sense of taste and appreciation of food is reinvigorated—so I can’t think of how to help. I’m sorry you’re having this reaction, though. Could your chalky mouth be a sign of dehydration? Maybe consume a bunch of fluids—or yogurt and kombucha to repopulate your gut with some good bacteria—and see if that helps.

      Also, I’m curious: How do you feel after fasting compared to after your other cleanses?

  35. Kris Avatar

    Hi there!

    I’ve been doing Intermittent Fasting now for over a year. The first 6 months i lost 45 lbs, but now i’ve been on a steady plateau for quite some time, so i want to try a long term water fast now. 1 Question. Regarding social situations. How do you not eat when you’re surrounded by a dinner party, or forced to go to Sunday brunch with a grandmother that only cooks old school with lard every single week? I can see friends and family getting concerned and making fun of me when i tell them about fasting. I can’t avoid these situations and that’s mainly what’s holding me back from starting 🙁

    1. Chris Avatar

      Hey Kris, If you’ve managed to prove to yourself and your family and friends that intermittent fasting works (they can’t argue with 45lbs in 6 months!), don’t you think they’d be more receptive to multi-day fasting? Either way, why not try 3 days, then maybe 5 days, so that you don’t need to skip Sunday brunch? Push come to shove, you can send me in your place. Grandma’s cooking with lard sounds delicious!

  36. Diana Avatar

    Great article but I think I enjoyed reading the comments even more. You do a great job of responding without taking offense with some of the more critical commentators.

    I have a question about the water you drink. I see a lot of people recommending adding electrolytes to their water but have never seen anyone recommend drinking electrolyte water. I’m wondering if there is something I’m missing on this. Personally, electrolyte water keeps me in the bathroom every half hour so it’s not my preference when working but I figured I could add during my fast. Any reason I shouldn’t?

    1. Chris Avatar

      Thanks Diana! Unless I’m missing something, there’s no difference between drinking electrolyte water and buying electrolytes, mixing them in water, and drinking that. Maybe price, I guess. But as long as the electrolyte water has very little to no calories and preferably no sweetener (since zero-cal sweetener can still simulate insulin responses and hunger hormones apparently), there’s no reason why not to. As far as peeing ever half hour, I’m not sure it’s avoidable when fasting if you’re drinking as much water as you should. If you or anyone reading this has any tips on how to retain the water better, I’m all ears.

  37. Pete Avatar

    Such great info! I’m on day 4 of a 7 day fast and feeling great! Because I feel so good I am considering extending my fast to 10 days.

    I would love your input on something I can’t get good info on. Cannabis while water fasting. After all the research I have done, it seems that the only reasons it’s not recommended while fasting are that it increases appetite and also that the smoke is not recommended as it dries you out. The increased appetite has not been an issue for me at all. If anything, I think weed has helped make my fast 10 times easier. As far as smoke drying me out, I use a vaporizer which eliminates the smoke toxins that seem to be the concern. Is this anything you might have some input on? If it’s aiding my long fast, am I ok to continue using my vaporizer?

    1. Chris Avatar

      That’s awesome that you’re feeling so good during your fast, Pete. Hopefully it continues to go well for you.

      I haven’t come across anything on weed while fasting. I can’t imagine smoking a vaporizer has any effects on your metabolism or digestive system, so if you don’t get munchies or feel dried out from getting high and it’s helping you with your fast, why not? But that’s just my uninformed two cents.

  38. Cherise Thesner Avatar
    Cherise Thesner

    Hi Chris. Thank you so much for all this wonderful information. I must confess I did not read through all the comments so this question might have been asked before, but how often do you fast (ie 1 week every 2 of 3 months). I have tried water fasting before but I’ve always struggled to get past day 2, but want to try again for health reasons.

    1. Chris Avatar

      Hi Cherise. I try to do a 5-day fast once or twice a year, a couple more 3-day fasts, and regular 36 hour fasts. But everyone’s different. I’m fit and health-problem free so I just do it out of convenience (when Kim’s not around to cook or when I’m swamped with work), when I feel like I’m getting “addicted” to food again, and for general longevity purposes. As most people will agree, getting past day 2 is the hardest. That and the last day when you’re looking forward to food. What also helps a lot is to get accustomed to just 1-2 meals a day (no snacks) and/or to really cut out processed carbs. Hope that helps!

  39. LA Girl Avatar
    LA Girl

    I started the water fast before I read this and great to see all the info! I’ve done them before for 1-3 days but now I’m on day 4 and not hungry at all. At home, I eat ridiculously healthy all organic, nuts, fruits, veggies, grain, no artificial ingredients but I go out often to parties and events with catered food, and sometimes it’s hard to avoid crap food, even though I remove fried sections and empty carbohydrates (and I drink too much alcohol lol.)

    I feel so full of energy after 4 days of the water fast and not hungry at all. Is there a point when it becomes dangerous for doing it for too long? I have no desire for food! Food is starting to feel like a foreign substance. What is the point when your body starts eating itself? I’m really enjoying the benefits and extra energy and at this point, feel like I could continue for quite a while but fear permanent damage to my body. (I’m afraid to ask my doctor about this or he’ll think I have an eating disorder—I’m not overweight or anything.) Or how do you know if you’re actually developing an eating disorder? It’s starting to feel too good not eating…

    1. Chris Avatar

      I sometimes ask myself if I have an eating disorder, too. And so do people close to me who can’t comprehend not eating and feeling good, not horrible, because of it. Those doubts vanish as soon as I have a bite of food after a fast and love it so much I know there’s no way I have an eating problem. From the way you describe your situation, you seem to be in a similar boat.

      As for when to stop a fast because it starts to get dangerous, the only advice I can provide is to listen to your body. When you no longer feel great, eat.

  40. DD Avatar

    I’ve been an intermittent faster for years (intentional and otherwise); recently, I completed a 24 hour fast and decided it was so easy I ate well and tanked up on supplements for 48 hours then began a 21 day fast. I made it eleven, but only for the fact it coincided with a family visit and sitting around a table being the only one not eating seemed strange especially seeing the work the cook was doing. Since my arrival home I’ve been attempting to begin another 21 day fast; for five weeks I’ve been trying to get it going and not making it past 18-24 hours. I’m in menopause on HRT and keto/low-carb with a few cheat days a month, but those cheats are mostly under 75g of carbs. Making sure to be in ketosis before beginning fast but can’t figure what is causing the roadblock. It seemed so easy the first time and worried now eating under 500 calories a day has started a starvation mode with the almost but not quite fasting; has anyone else experienced this? Can only think this is menopause related but don’t plan on giving up.

    1. Stacey Avatar

      I usually do one 4-5 day fast per quarter, plus maybe 10ish ad hoc 36 hr fasts per year, and two meals/day otherwise (either skipping brekkie or dinner, but maintaining at least 1500 cal/day – I’m 5’4, 130-140lbs, lots of muscle). I can’t speak specifically to menopause as I haven’t gotten there myself yet, but I have faced the same “wall” you’re facing where my body was just balking 2 days into a planned 5 day quarterly fast – and it started the quarter after I pushed through to a 7 day fast which I had not done before. I had started and failed my quarterly fast at least four times, Kept beating myself up about it (berating myself for Not having discipline etc), which that type of negative self-talk is very detrimental as all women know too well. Anyway, I made a deal with myself to just relax, not berate myself, start a 36-48hr fast, and if I felt like it, continue on, and if not, that’s fine too – would just clock the fast as a 48hr fast. I had to give myself permission to not do a long fast and short circuit the mental self shit-talking and tying it to my self worth – forcing myself was the problem and it was a kind of mental block I had to *gently* work around rather than bulldoze through. After that I resumed 4-5 day quarterly fasts with no issue, starting each one with a new openness to total fasting length.

      If it helps for motivation: the vast majority of fat lost during extended water fasting is deadly visceral fat (vs relatively harmless subcutaneous fat), which menopause triggers significant production and storage of visceral fat. So menopause is a great time to start or maintain a fasting regimen. Just be gentle with yourself. Fast with intention, but be open to the very significant health and longevity benefits of 36-48 hr fasts, too – in fact a lot of research says the the metabolic benefits of fasting drop off precipitously after 4-5 days and that there is little benefit (except weight and fat loss) to extending beyond 7 days. Also, for me I have to start the electrolytes and salt within the first 48 hours to make it through a 5-7 day fast or things get out of whack starting in days 3-4 bc I sweat TONS when I exercise (literally 3-4lbs less on the scale after a 90/minute session and I’m the ONLY person in class sweating that much!). Good luck!

  41. Olivia Avatar

    Thank you for this amazing article!! Really relatable and funny – currently on day 5 of a water fast and was going to break my fast later today but you’ve inspired me to continue to 7 days!! Literally covers all the basic need-to-knows about water fasting in awesome, love it! Great work, thank you 🙂

    1. Chris Avatar

      How nice of you to say, Olivia! Thanks. I hope your “bonus” two days of fasting when well for you. All the best.

  42. Alisa Avatar

    Have you ever tried the master cleanse? I have a few years ago for 30 days and it was a huge success. A water fast seems more simple yet harder. I was going to start a 30 day master cleanse and then lead into a 20 day water fast because I read somewhere that it’s easier to follow through that way. However, if it’s more simple and has the same or better effects, I’m thinking of just doing a 50 day water fast. Do you have any comparisons of the two?

    1. Chris Avatar

      Hey Alisa, I hadn’t heard of the master cleanse so I looked it up. It’s fasting with sweetened lemonade, teas, and salts? If it was a huge success for you (you’ve sustained the weight loss or other benefits you got from it), congrats. If the benefits were temporary, I might suggest something less-extreme than 30-50 days of anything and trying more periodic, shorter fasts that become a regular part of your lifestyle instead. All the best!

      1. Maricar Barrion Avatar
        Maricar Barrion

        Hi, thank you so much fir this awesome article. I did water fast twice already. I did that fir seven days. You’ve mentioned that we can do infused water. I just wanna know what is the best fruits i can add w/c is lowcarb. I’m planning to get back in ketosis. 🙂

        THANK YOU!

        1. Chris Avatar

          Hi Maricar. Any pure infusion (i.e. where you’re not smashing the fruit to release its sugary juices) will have essentially no calories, so do whatever you think tastes best. You’ll find lots of inspiration from all the funky infused waters at hipster cafes these days!

  43. Bee Avatar

    Hey! Just a few things worth noting-when doing a prolonged fast it’s so important add a teaspoon of pink sea salt to a good amount of water, the body will need the potassium and sodium. Or a multivitamin. Depriving your body completely then having a big meal to break a fast can be dangerous, something about the sudden fluctuations of mineral levels. Adding salt/multivamins eliminates the dizziness and light headedness I experienced. Also when breaking a fast, its a good rule of thumb to ease your way back in with easily digestible foods for half the amount of days you fasted for (haha I noticed your post fast feast pictured), I befeit from 3 days fasting and cure my cravings for fresh foods by juicing my fruit and chucking a bunch of good stuff in a pot and blitzing it into a soup. Otherwise if I have big meals I feel quite uncomfortable and sore right after a fast, also some people get quite sick in general, could be a lack of proper mineral intake during the fast.

    I’m no expert either but this has been my experience!

    1. Chris Avatar

      Hey Bee. I hadn’t heard of any such dangers of mineral fluctuations, nor of the rule of thumb for refeeding after fasting, so thanks for sharing that info from your own experience and research. I suppose we all have different reactions to refeeding based on many factors, seeing as you say some are so sensitive to it while I, for example, can go nuts (and chocolate and sushi and fruit and sandwiches) after an extended fast to no ill effect. That said, we’re in agreement that the best approach to refeeding is to go slow, start with easily digestible foods, and progress based on how your body reacts.
      Thanks for pitching in you perspective. All the best!

  44. Bee Avatar

    Excuse my generalisations BTW, I’m having a foggy fast day but there are some good googling points in there for anyone that wants to know about all the how’s and whys!

  45. Ashley Avatar

    Ok, I confess I did not read all the comments, although I did read some… I have been an intermittent and water faster for a long time. (Way before it became cool. Haha) I enjoyed your blog and the information and enthusiasm you provided. I tend to fast several days consecutively during the month and then do an every other day fasting schedule when I am eating. I guess I am curious if you think this is healthy, worthwhile, consistent? Also, I try to eat low carb on food days, but dang it Oreo’s are delicious. Have a good day.

    1. Chris Avatar

      You’re on the Oreo diet, eh, Ashley? Haha, that’s a new one.

      With the major caveat that, like I say over and over, I’m no doctor and just sharing my experiences and what I’ve read from doctors, if eating every other day works for you (i.e. you can consistently keep it up and fit in within your lifestyle, and you feel fully energetic from getting enough fuel on feeding days… oh and it doesn’t make you crave Oreos even more) it’s fine.

  46. Capucine Duncan Avatar
    Capucine Duncan

    Great blog post! This may be a stupid question but, if I don’t have sea salt around, can I use regular table salt or even pickle juice instead??

    1. Chris Avatar

      Hey Capucine. Nice name! And not a stupid question. The problem with table salt is that it’s refined to remove the trace minerals sea salt (or Himalayan salt) have that can be beneficial to you while fasting. Pickle juice is a great idea, though! For the same reasons pickle juice helps prevent cramping it can help you stay hydrated fasting.

  47. Jeremy Avatar

    I’m starting my fast today and have a couple of questions. Wouldn’t bone broth break a fast? And if not how much can you drink? Also should I take a multivitamin if I’m doing a 5+ day fast? Thank you for the article it was great!

    1. Chris Avatar

      Hey Jeremy. Some sticklers will say anything other than water will break a fast but, as I wrote, you can get almost all of fasting’s benefits while adding things like bone broth and multivitamins. Pure bone broth has very little calories and mostly minerals, so a cup a day won’t break your fast. You don’t need to take a multivitamin, but I find it helps keep me hydrated (and less light-headed). As these comments make clear, everyone’s fasting experience is different, so it’s a matter of finding what works best for you.

      1. Brittany K Worthy Avatar
        Brittany K Worthy

        Chris! I loved your article! I am on day 5 of my fast and I am becoming increasing concerned about the vitamins that my body may be lacking. What type (Amazon links help!) of multivitamins do you use?

        1. Chris Avatar

          Hi Brittany. For me, what does the trick is homemade bone broth plus some slow-release magnesium at night and sea salt in my water throughout the day. I’ve tried all sorts of powders and they’re fine, but I don’t know which to recommend (or why). If someone more knowledgable out there has impartial advice, I’m all ears, too.
          One tip another reader sent me is the “Laird Superfood” coconut water powder. The word “Superfood” always makes me wary, maybe it’s worth giving a go?

  48. Nathan Ross Avatar
    Nathan Ross

    Hi you may have mentioned this but I was too lazy to read every comment how about exercise will I have any energy to exercise? Also I’m addicted to coffee! I don’t need sugar in it and I don’t have milk can I still drink coffee and fast on water?

    1. Chris Avatar

      Hey Nathan. You’re too lazy to read comments but have the initiative to exercise? Haha. Go ahead and have black coffee on your fast if you can’t live without it. And as for exercise, you might feel energetic while fasting, but when you try anything intense you’ll probably notice your energy seeps from you fast. That’s why when I fast I stick to low-intensity exercises. But some commenters have felt otherwise. See how you feel and adjust accordingly.

  49. shailesh Avatar

    hi Chris,
    was searching the net and bumped into your blog as I wanted to do my research work while beginning my water fast for coming nine days.

    just on day 1, not considering last meal at 8pm last night.

    your blog with such a lot of participants , with their queries and your honest replies is so very encouraging and informative.

    1st have been doing intermitent fasting since last four months and am.practically off junk food. being a vegetarian I eat more of sprouts, greens and healthy food and ahandful of nuts. definitely no refined flour or aerated drinks or coffee or sweet foods. ( sweet from fresh fruits is an exception and not exceeding 2 portions a day)
    2 nd had done a waterless fast last week and got more encouraged to do this nine day water fast with water, green tea and maybe a few herbs like fresh ginger and fresh mint.
    3 nice tip to add rock salt to the water to maintain the minerals.
    4. I average minimum of 10000 steps a day by mild jogging or cardio.

    what I would like to know is
    a. do you recommend a continuation of 10000 steps a day.
    b. I take thyroid medication. any one have experience of the affects of stopping or continuing their thyroid medication.
    c. any recommended exercises to main muscle mass as I have been reading one loses muscle mass from day 4 or 5..

    by the way my age is 59. in physically fit condition and no known health conditions except the thyroid.

    also having been losing inches by intermittent fasting but not much of weight loss.

    any pointers will be appreciated.

    1. Chris Avatar

      Hey Shailesh, Sounds like you’re well-prepared for a fast. Way to go! I can’t help you at all with B. For A, definitely 10,000 steps a day should be doable while fasting. That sort of slow and easy exercise is my favorite way to stay active while fasting, too. But everyone’s different, too, so do whatever feels best. For C, Dr. Fung uses a fun analogy of your body being a train. While fasting, it’s first going to use the coal (i.e. your fat) to run the engine, and only when that runs out will you have to strip the walls of the carriage (i.e. your muscle) to burn the engine.
      If you’re losing inches but not weight, maybe you’re gaining muscle or bone density? Have you tried a DEXA scan? We shared our DEXA experiences here: http://staging.theunconventionalroute.com/dexa-scan/.
      All the best with your fast!

      1. shailesh Avatar

        the fast was a super experience. the 9th and 10th day for me.were the toughest. lot of toxins from the body were out.
        will discuss with my doc for a dexa scan and if available in my city.
        started going to gym to do some weights and body stretching so as to maintain muscle tonality.
        gained back 2 kgs of 5 kgs lost guess expected that.
        inch loss another inch but now it’s appears to be a bit slower.
        now I average about 18500.steps a day.
        I feel a good 7 to 8 hours complete sleep helps a lot more for body to re enegise.


        1. Kristy Avatar

          Hi Shailesh, Wondering if you kept taking your thyroid medication while fasting? My thyroid medication contains sugar (why?) so I’m considering stopping it but I get depressed so I’m a little afraid of stopping. I just don’t want it to keep my body from healing. I also take HRT and am not sure whether to stop taking that for awhile.

  50. Jen Avatar

    Won’t drinking miso soup break the fast? As it has like 35 calories per cup? Want to try it, but I’m also 2 days in and don’t want to kick myself out of a fasted state. Thanks! 🙂

    1. Chris Avatar

      If you need it to keep going, do it. And if you feel bad about yourself, check out some of Valter Longo’s research on Fasting Mimicking Diets, which seem to allow people to consume hundreds of calories daily while still getting most of the benefits of fasting. A couple miso soup’s nothing compared to that!

  51. Meg Cho Avatar
    Meg Cho

    It doesn’t make any sense to claim that someone who drinks copious amounts of water for extended period of time is mostly losing water weight. If the scale is significantly lower after your fast and you have been drinking at least 64 ounces of water every day there is no way you are only losing water weight. That makes absolutely no sense. Take it from someone who has effectively lost significant amounts of weight doing water fasts and didn’t gain more than a few pounds back after I started eating again. The body doesn’t burn water for energy when it’s deprived of food for long periods of timer, it burns FAT.

    1. Chris Avatar

      Hey Meg. Your organs, especially your kidneys, dump a lot of water while fasting and reabsorb it after. And drinking tons of water will just go right through you. A pound of fat is 3,500 calories, so an average metabolism will burn half that daily.

  52. Jacques-Olivier Avatar

    hi Chris,
    I’m in the middle of my first water fast (4th day today) and simply wanted to thank you for putting this post together, really nice!

    1. Chris Avatar

      Thanks Jacques-Olivier! I take it since you’re thanking me and not screaming at me your fast is going well. All the best!

  53. IBU Avatar

    Glad I found this article. I’m about to put my head down after Day 1 safe in the knowledge that I’ll be whacking in some Himalayan salt with my lemon water tomorrow morning. I’m also encouraged to learn that having been on a ketogenic diet the last few weeks, and having sacked-off caffeine a few months ago, I’ll have mitigated some of the less-than-pleasant side effects of entering a multi-day fast. I think (hope!!) I’ll sleep easy now. Great article, and thanks again!

    1. Chris Avatar

      Awesome, IBU. Yeah sounds like you’re well-prepared for fasting. Enjoy not eating!

  54. Benjamin Tucker Avatar
    Benjamin Tucker

    Awesome article friend! So the longest I’ve made it was 8 days, with 4 5-day fasts, and quite a few 48-hour fasts (all strictly H20 with 1-2 black coffees each day).

    What I’ve noticed personally is by day 5 I’m almost passing out or falling over. I’m a big guy (ex bodybuilder) 292 pounds mostly muscle; is this why it seems so hard to pass 5 days? I’ve never tried supplementing with salt or electrolytes, will this make the difference for me? Because my heart is set on eventually regularly doing 21-day water fasts.

    If salt will help I’m all over it man, eager to hear your insight / thoughts. PS fasting has been huge for me Spiritually, and why I do it.

    1. Chris Avatar

      Thanks Benjamin! I had real similar experiences when trying pure water fasts and never again with electrolytes, so there’s a good chance that could do the trick for you.

      I hadn’t thought of the term “spiritual” to describe part (or a lot) of fasting’s benefits, but I totally get you. I’m going to think about that more my next fast. Thanks for sharing.

  55. Roberta Avatar

    Hi, Chris. I’m Roberta.
    Quick question.
    Is it of to fast regularly? And how should it work?
    (For example, a 5 day water fast every two months would be ok?)

    1. Chris Avatar

      Hi Roberta. Nice to hear from you! I can’t give you a definitive answer because A) I don’t know enough and B) It depends on you. Have you already done 5-day fasts before? I’d say it all comes down to how you feel. If you’re physically and mentally up for it and come out of each fast feeling great, go for it. Otherwise, adjust accordingly. All the best!

  56. Ben Avatar

    Just another quick question – does anyone have any thoughts on wether bentonite clay would be ok to use during the water fast? As it has no calories and cannot be absorbed by the body, but is effective at leeching toxins out?

  57. Adelia_Savage Avatar

    I just finished my first 3 day fast after reading this guide and one thing that struck me is that hunger has a peak..as in, I felt the same level of hunger on day three as I did on day 1. In my head, I’d imagined that it would get gradually worse over the 3 days until I couldn’t take it anymore but it was actually pretty manageable as long as I was able to distract myself. Thanks for this compilation of advice and personal experience!

    1. Chris Avatar

      That’s an interesting point, Adelia. I imagine that when you fast too long, to the point you’re hurting yourself, hunger may step up a level. But for most of us that’d take ages to get to. Was your hunger constant, or, in my case and that of most people I talk to, would it rise up during your typical eating hours? Congrats on your first 3-day fast, by the way!

  58. Jordan Avatar

    I did a thirty day fast before.
    21 days water 3 days juice, 3 days water, and 3 days juice. It was incredibly difficult getting through the water phase because I did only water.

    This time I am doing a 21 day fast but also included broth, tea, electrolytes, and some clean juicing. I feel noticeably more energized and getter overall. I’m wondering if the juicing kinda kills the fast though or not?

    Also thanks for the article. Great read.

    1. Chris Avatar

      Wowzas, Jordan! If you feel more energized and better overall while fasting, and continue to feel great after while feeling/seeing benefits, I’d say great. Do what works for you. Maybe you won’t get the exact same benefits of a pure fast, but the trade off to the benefits you get from doing it your style could easily be worth it.

  59. Jarah Avatar

    Will chewing cardamom or cloves break my fast?

    1. Chris Avatar

      Nope. Chew on!

  60. Steve Avatar

    Hi Chris, thanks for the article! I came across it on the 2nd evening of a fast brought about by an article I read on Medium. I had toothache and nasal ache and couldn’t sleep, and was just googling that and fasting, and eventually came across your article. Super helpful! I bought Dr Fung’s ebook, and have read it all now. I decided to extend for the 20 days to try and achieve a body weight reset now that I understand it better.
    I have just completed day 8, having added a stock cube cuppa at the end of the day, and removed half a cup of tomato juice and 1 cup of orange juice I was having initially, after reading Fung’s comments about fructose being an arrow to the liver. I am feeling better now than I was in the first two days, very little problem with hunger – I actually carved up a roast leg of lamb and packaged it for the freezer without eating any, a task impossible for me usually. I would have liked to eat some, but it was no trouble to resist despite the fabulous aroma. I have lost about 7kg so far, though I know about half of that is alimentary tract contents which will be added again when I recommence eating. Still, if I can do the next 12 days, which feels quite possible at present, I should make a dent in my 121 kg total original weight. I would like to get to 100kg in the next year or so, and maintain it.
    Thanks again!

    1. Chris Avatar

      That’s fantastic Steve. It’s sounds like you’re a fasting master, having put yourself through the ultimate test of carving up some delicious food without giving in. I bet you licked your fingers a bit more than usual though, right? Haha. Has fasting had any effect on your nasal and tooth aches? Hopefully so. And hopefully you reach your 100kg goal. All the best!

      1. Steve Avatar

        Hi Chris,
        Day 15 today, all still going well, I am 110kg this morning. The nasal and toothache has not recurred since the second night, I’ll see if it recurs next time I start a fast. I am starting to think about eating regimes when I end this fast. I am inclined to restrict carbs as much as I can, stick with meat and vegetables mostly, and maybe have lunch and dinner in an 8 hour window. Do you have any suggestions?

        1. Chris Avatar

          Hi Steve. Amazing! I’d suggest not making too many changes all at once. Rather one at a time. Cutting to two meals a day would be the first step I’d suggest. For me, at least, that’s made huge changes in controlling my hunger. And it’s not so hard after fasting for so long. Cutting carbs from there (or, even easier, cutting processed foods) is then not so difficult. Or you can try all at once, but just remember not to be too hard on yourself or too strict about making exceptions since big picture you’re doing amazingly well. All the best with kicking those next 10kg!

          1. Steve Avatar

            Thanks Chris!. The 20 days was quite bearable, and post fast I have found it easy to stick to the 8 hour eating window. Meat and green veg mostly, some nuts. I feel full at the end of a meal now, a new experience! With more salts available in my food, my body has rehydrated somewhat, I feel this especially in my eyes. I have stabilised around 110 kg, which I am very pleased with, got to 107kg last day of the fast. I’ll investigate electrolytes to help next fast, planning to try and get another 20 days in before Christmas.
            Thanks again for your blog which has been so helpful!

          2. Chris Avatar

            Down 14kg already? That’s remarkable. You sharing your experience has been eye-opening for me (speaking of which, “especially in my eyes”? That’s interesting!) and undoubtedly helpful to others who read it. All the best with your empty-advent Calendar December!

  61. Charles Avatar

    Hi Chris
    Great blog well written – about to kick off on my second 7-day fast – this time wanting to incorporate a ‘greens’ powder (vital greens) and I’m hoping you could give me your thoughts on whether that would jeopardize my transition to ketosis

    1. Chris Avatar

      Hi Charles, I’m not familiar with vital greens and not much into keto so can’t say for sure. If you can, try a little bit at first to experiment, see how your ketone levels react (and how the rest of you reacts too) and go from there. All the best with 7-day fast #2!

    2. Ken Avatar

      Hey mate , I had considered the same, I guess it comes down to calories. I use it as a meal replacement for breakfast when modifying diet sometimes & it leaves me feeling full . Let me know what you dig up as I’m in a ten day fast but don’t have the original container.

  62. Lewis Avatar

    Hey Chris,

    I found this guide to be really helpful and a good reference for fasting! I’ve been playing on a fast for a while now and I know I have the dedication & drive to do it, but there’s a problem. You see, I still live with my parents (20, college student) and they believe that fasting is “torturous”.

    My question is, how would you go about fasting when living with people who do not approve of it? Moving out is not an option for me since I don’t have the money, so I’m pretty much stuck with them.

    Thanks again for the article!

    1. Chris Avatar

      Hey Lewis, Haha, yeah moving out just so you can fast would be a bit extreme. If your parents force feed you at home maybe: a) Plan your fast for whenever (if ever) they go away for a couple of days, b) Go for a weekend away with some friends and fast, or c) Try to understand what your parents’ concern is so you can find some common ground and eventually get them to be o.k. with you trying at home. Maybe they’ll join too (though I doubt it, seeing as my parents, despite being open with me doing whatever “craziness” I want, would never try themselves). Here’s hoping you manage to sort something out!

  63. Jamious and Christy Avatar
    Jamious and Christy

    Thank you! We found your post to be very helpful and inspiring.

    1. Chris Avatar

      Thanks to you too, Jamious and Christy. Your and others’ comments definitely inspire me and undoubtedly others to give it a go, too.

  64. Julia Garvy Avatar
    Julia Garvy

    Hey Chris, I’m on day 15 of my water fast and I’m now starting to get really dizzy any time I get up. I believe this is due to low blood sugar, how can I raise it without breaking my fast?

    1. Chris Avatar

      Hey Julia, Have you done a blood sugar test to see if that’s the cause or not? Or could it be other minerals? A bone broth may be in order. If you’re really having a tough time, eat, feel good, then fast again when your body’s ready.

  65. Stanley Lawson Avatar
    Stanley Lawson

    what kind of water do I drink, can i buy a filtration system for my kitchen sink

    1. Chris Avatar

      Hey Stanley. Yeah sure. Any kind of water. Filtered, bubbly (a nice treat when fasting), tap, ice cubes.

  66. Laura Avatar

    This is awesome and very motivating. I’ve been struggling because last night I ate a couple pieces of mozzarella (I sometimes sleep eat) and today half an avocado. I was thinking I was going to have to mentally go back to day one (I’m on day three) but after reading this I feel like you’d say to just keep moving forward 🙂 That is exactly what I need too. Every time I get discouraged with fasting I fall off the wagon HARD. Having Hashimotos hypothyroidism fasting is the only thing that’s given me any respite from the fatigue and swelling and your guide here is the most motivating thing I’ve found. Thank you for writing it. I appreciate you taking the time to help other novices.

    1. Chris Avatar

      Thanks so much Laura. Your touching comment about how motivating this post and these comments are motivates me! All the best.

  67. Lucy Avatar

    Hi Chris I am on a 30 day water fast to loose weight. Currently at day 10 and will continue to the end unless I start feeling terrible. At the moment I feel like normal, just more focused to deal with work I have been putting off for a long time! How soon after the end do you think I could do another fast? I will probably do 20 days next time if all goes well as I have a lot of weight to loose, like 100lbs in total to reach my goal weight. I had heard that you can loose all your hair on extended fast, which is a worry? Also any advice about loose skin which I imagine will follow?

    Great article by the way and thank you for sharing!

    1. Chris Avatar

      Hi Lucy. Wow! Way to go. All I know about your loose skin question is that according to Fung most people who lose tons of weight (like the guy who didn’t eat for a whole year and lost 180ish pounds) don’t have that problem. The skin shrunk with them! On your questions about hair and when you can do your next fast, I don’t know. Based on what others have commented here, side effects of fasting vary a lot, so if I were you I’d keep going and do what feels right. If notable amounts of hair start falling out, slow down.
      All the best, Lucy. Here’s hoping you get 100lb-worth of skin shrinkage!

  68. Robert e Greer Avatar
    Robert e Greer

    Thanks for being here. I’m 78. Overweight. I’ve dropped from 280 to 212 in last year just eating right and working out. But have been stuck at 212 or so for 4 months, thus trying fasting. I tried fasting last year and started seeing colored bubbles and slightly dizzy after 3.5 days. Ate and got sick (hadn’t studied on how to start eating again).

    This time I’m on day four and feel ok. Slightly lightheaded, but otherwise fine. Not hungry.

    My question has to do with weight. My weight is up 5 lbs from 210 and my body water is up from 47.1% to 51.4%. I would think the Lasix I take would control my water level. Urine is very clear and frequent. The water thing seems so strange because all I read is people loose water when dieting then gain it back later. I’m drinking about 5 16 oz bottles of water a day and three large coffee’s. My doctor pushes me to drink a ton of water. At least one bottle I add Electrolyte mix.

    As a side note I’m hooked on Nicotine Lozenges and checked yesterday and they do have artificial sweetener and salt.
    Any advice on the water question would be appreciated.

    1. Chris Avatar

      Hi Robert. Way to go on dropping 1/4 of your bodyweight. Amazing. The weight of a 10-year-old child!

      I don’t have any ideas for you about your water question, sorry. Just a question: Is the extra water causing you any problems other than the extra weight? If not, then why worry about it? Seems like you have access to some detailed body composition measurements, so why not track lbs of body fat only?

  69. Dolores Avatar

    Great post, however to make it more accurate I think you should read more about what Dr Fung says regarding long-term fasting and grehlin.
    You’ve said it makes you less hungry, however that isn’t true, the grehlin thing can actually block your satiety response, resulting in overeating, which is why it’s really important to refeed properly, and ideally in a keto or carnivore way to help with hormone adaptation.

    1. Chris Avatar

      Thanks for commenting Dolores! Isn’t leptin the satiety hormone? As far as I understand, leptin does go down when you fast (i.e. you have less hormones telling you, “You’re full so stop stuffing your mouth!”) but at the same time your leptin resistance goes down (i.e. even though there are fewer hormones telling you you’re full, your white noise-blocking headphones are off so you can better here what they’re telling you).

  70. Keith ivany Avatar
    Keith ivany

    I just wanted to say that fasting saved my life. 14 years ago I was at the point of suicide due to being born paralyzed from the waist down, falling down a flight of stairs fracturing my skull, molested at age 5 by an aunt, alcoholic father, molested by a church leader right in the building of a church for 4 years, molested by another married woman in the church for a year, cracking my skull open again at age 7. I got into ever addiction there was mainly pornography and food. I just wanted my brain fixed and spent 30 years in addiction. 14 years ago I went on a 40 day fast that saved my life. I was forced to deal with wrong thinking, major medical problems, hatred, rage, and unforgiveness. By far it was the hardest thing in my life but it is the best thing that ever happened in my life. The benefits are literally out of this world!!!! Would do it again!!

    1. Chris Avatar

      Wow! That’s quite the powerful endorsement of the spiritual benefits of fasting. Congratulations on finding fasting as a solution, powering through, and making such an incredible turnaround. And thanks for sharing your story here.

  71. Hussain Avatar

    Hello brilliant information thanks.
    Just like to ask should one refrain from hard workouts when fasting?

    I did the OMAD diet for a week and the following week I started a water fast. I began the day with a liters of water and a early morning 2 mile hard run, by the time it was bed time I developed a cold fever, I was shivering through the night.
    I just kept telling myself that it’s only the body improving itself.
    Is this a good thing?

    1. Chris Avatar

      Hi Hussain. A cold fever and shivering through the night is definitely not a good thing. But feeling cold is a common side-effect of fasting. Some say that adding more minerals (magnesium, sodium, potassium) helps. Have some with your water in the morning and see how it goes.

  72. Eve Avatar

    Is it ok to water fast one day, juice the next and water fast the next day? Or does this defeat the purpose of fasting all together? I’m on day 2 of water only and am super debating if that would be best, not from hunger but for over all health benefits!!

    1. Chris Avatar

      Hey Eve. If you can fast without juice, do so. And if you feel you need some calories, rather consume something that isn’t high in sugar, like juice is. Juice, in general, is not healthy, fasting or not.

    2. Jaclyn Avatar

      Try chicken broth or miso broth. Has a lot of nutritional value, and very low in sugar.

  73. Jaclyn Avatar

    Hi Chris. I know it’s been a while since you wrote this, but just wanted to thank you for all the helpful info! Just one question: I am on day two of a 60 (hopefully) day fast, and am beginning to feel nauseous, what should I do?

    1. Chris Avatar

      Hi Jaclyn. You’re welcome. Sorry to hear you’re feeling nauseous. Listen to your body (i.e. don’t push it if you feel like crap), consider going slow in your foray into fasting (eat some food, stick to a healthy diet and give it a go a bit later), and, if you can’t wait, see a doctor for help. If you insist on pushing through, this, this, and this Reddit thread has some suggestions. All the best!

      1. Jaclyn Avatar

        Thank you Chris! I’m on day 4 now and doing better. I’m assuming it was a combination of having a bad diet prior, and not staying hydrated enough. Feeling better now

  74. Melissa Avatar

    I did a 5 day fast last Sept, quit day 4 as cold & hungry.
    This Jan, I’ve done 2×3 day fasts so far, eating zero carb, moderate protein, for 4 days then fasting for 3. I plan to do this twice more this month.
    I’d like to do a longer fast but think that the cold symptoms are due to a drop in REE and I don’t want that. I am 56. I am not so heavily invested in longer fasts that I’ll push through the cold but wonder what causes it. I am fat-adapted I think. Would it be a lack of sufficient electrolytes? I generally drink a couple of black coffees and sea-salted water.

    1. Chris Avatar

      Hey Melissa. From what I’ve understood, feeling cold on prolonged fasts is common and due to increased blood flow to your fat stores at the expense of your extremities, which thereby get cold. There’s a chance it could be hypoglycemia, so you might want to test your blood sugar levels to (hopefully) rule that out. Sorry to say, but I’ve not come across any way to deal with the cold other than eating or doing something to warm up (gloves, tea, heater, etc.).

  75. Melissa Avatar

    Thanks, Chris
    I didn’t see any sign of hypoglycaemia at the time. Currently just eating and breaking fast rather than continuing. I’ll do more frequent rather than longer and focus on getting better sleep and better fat adaption.

  76. MaryLou Avatar

    Hi Chris
    Very informative post. Thank you. I do low carb intermittent fasting but last week I did 48 hr fast and felt good! So currently I am on hour 37 of my fast and I am hoping for 72 this time
    I drink alkaline water (essentia), black coffee, club soda, and green tea.
    I use the Zero App for tracking my fasts.

    1. Chris Avatar

      Great to hear MaryLou! I too did intermittent fasting and reduced carbs before my first fast and felt good. It seems to help—kind of like training with shorter jogs before jumping into a 10km race. Hopefully your 72 hour “race” goes well!

  77. Beth Avatar

    Hi Chris,

    Great article! All along you and others mentioned adding potassium, magnesium and electrolytes into your fast . . . What specific sources / kinds do you use for this. Tablets, premixed solutions or something else? I’m in a very small community and may need to order via Amazon or other source. Thank you!

    1. Chris Avatar

      Hi Beth. Good question. I don’t know nearly enough to know what specific electrolytes to supplement and why. From what I’ve read, sea salt or Himalayan salt is good for sodium and trace minerals and, from what I’ve heard from Dr. Peter Attia, a magnesium supplement like SlowMag can help. Bone broth (or miso broth for vegetarians) is another alternative for salts and minerals if you don’t need to go 100% pure water fast. Sorry I can’t be more definitive. Hopefully that helps a bit.

  78. BH Avatar

    Hi – I’m hoping someone can give me some insight into why I stopped losing weight while fasting. I‘m just finishing a 20 day colon cleanse. Water, tea and apple juice with the cleansing herbs. For the last 12 or so days I have not lost a single pound – even gained a few ounces. I have done many cleanses and fasts and this has NEVER happened. I do drink about one cup of homemade veggie broth a day but I can’t see how this would contribute to not losing a single pound in two weeks. I also have strong bowel movements everyday so this seems even more odd. Any insights would be greatly appreciated!

  79. Terri Shelton Avatar
    Terri Shelton

    What is the scientific research say about drinking distilled water, vs regular tap water, spring water, electrolyte infused water, etc? In other wards, what is the most beneficial water to be consuming during a water fast?

    1. Chris Avatar

      Interesting question, Terri. Scientific research on nutrition-related topics such as fasting is so complicated that I can’t imagine anyone has gone into such detail, or could come up with definitive answers on such a specific question. But if I’m wrong and it exists, someone please enlighten us.

  80. Me Avatar

    Showing a photo of you ending an extended fast with a BIG meal? IDIOTS. That’s precisely the opposite of how you’re supposed to resume. SMH.

    1. Chris Avatar

      Hi Me. It seems you’re passionate about what and how to eat after a fast.

      I didn’t feel like an idiot after eating that meal. I actually felt pretty great. But, then again, even Kim calls me an idiot from time to time, so maybe I am one. I’d love to hear your idiot’s guide to refeeding. Any quick advice?

  81. Ken Avatar

    Hey Chris,
    A down to earth discussion on fasting brilliant! I had done a 5 day water fast with a friend using just salt & felt great (although celebrated refeeding a bit strong -too much herb 🙂 Interesting to learn of the acceptable water additves as I’m currently day 8 of a ten day fast coinciding with quitting cigarettes (sheltering others from my irratability by doing this as i travel solo thru Tasmania) My health would have been better a year ago during the 5 day i felt jacked, this time maybe a bit more intuative listening to what the body says & resting, struggling with heartburn makes it difficult to lie down all the time . Mentally challenging & a little socially ostracising to be amongst upbeat fellow travellers sharing food & activities when they are key things I would usually be involved in. I went for a 3 hour beach walk on day4 that cramped my calf muscles so pulled back to short walks , noticing any time I have a quick burst of energy jump, climb, jog my heart feels enlarged so I back off. Otherwise my body still regulates temperature well handling these cool Tassie waters. I plan to ease into eating with lemon water ,electrolytes, broth , veg soup, sauerkraut, vital greens supplement up to 48hrs then adding in hemp seed oil , coconut water , eggs , potato, fish, nuts & a little fruit. In regard to the type of water query you had some good spring water lists calcium, magnesium & sodium levels it contains. My heartburn remedy has sucrose in it so I try to avoid it , any ideas?

    1. Chris Avatar

      Hey Ken,
      Kim and I have Tasmania high on our want-to-visit list. Lucky you! (Though yeah I imagine it’s tough being a solo traveler if you’re staying at social places like hostels. Being the “weird guy that doesn’t eat or drink.”)
      Based on your cramps and how you feel when you exert yourself, it sounds like you might want to try increasing your electrolytes. Or just open your mouth and swallow a bit when you go swimming, ha. I haven’t ever had heartburn issues (knock on wood) and haven’t heard of or paid much attention to how to deal with it while fasting. A quick search around the web suggests electrolytes and/or tea. Maybe give those a shot? And let us know how the rest of your fast goes.

  82. Shal Avatar

    Hi thanks for this post. I have previously done a 21 day fast and felt amazing at the end of it. I am planning on starting my 21 day fast again today.. just wondered do most people take vitamin tablets during their fast or do you suggest anything else?

    1. Chris Avatar

      Hi Shal. I’ve never gone close to 21 days, so sharing my personal insights would be like someone who’s been to the moon giving tips to someone who’s going to Mars. All I can suggest is if your previous 21 day fast went so well, stick with what worked then. Please chime in anyone else with more experience and expertise!

    2. Matthew Oakley Avatar
      Matthew Oakley

      I did a 23 day fast. I felt pretty bad for the whole time. The last week I spent mostly in bed. I drank only sparkling water (non-sparkling made me nauseous). I think it might be lack of electrolytes. I’m 3 days in to a 40 day fast. I’m thinking of having some bone broth every few days.

  83. Anneliese Avatar

    Just a little note. The foundation that Dr. Longo “generously donates” his proceeds to is his own company.

    1. Chris Avatar

      Thanks for the heads up, Anneliese. I’ve changed the text from “the Create Cures Foundation” to “his Create Cures Foundation.” Maybe I’m naive, but I like to think the foundation has altruistic objectives. At least it’s not the, “Build Doctor Longo a Giant Mansion Foundation.” If you have any doubts about the Create Cures Foundation, please share.

  84. China Richmond Avatar
    China Richmond

    What an amazing and motivational post thank you for taking the time to share it! I’d love to try the 7 day water fast however I work full-time and have a 5 year old so life is busy. Unfortunately I have zero chance of taking a week to rest up and take it easy and I still have to cook for my son so can’t avoid food at home or work (my desk is right by the kitchen!). Is it possible to successfully complete a 7 day water fast whilst working and generally getting through the every day activities of life?

    1. Chris Avatar

      Hey China. Oof, seems like in your case going straight into a 7-day water fast would be tough. Anything is possible, of course. Have you considered trying a shorter fast of, say, 1 to 3 days? If you can manage that a few times and feel ready to go longer, try adding a day or two. Maybe you’ll manage to work your way up to a week kind of like a weightlifter increasing their load. Or maybe you’ll find shorter fasts work for you and you don’t need to go so long.

      1. China Richmond Avatar
        China Richmond

        Thanks so much Chris for your reply a sensible suggestion trying to run before I can walk is probably a bit too much of a stretch I’ll start with a 2 day and work my way up!

    2. Jason Avatar

      Hi China.
      I’m currently on day 3 of a hopefully 6-8 day fast. I have previously done 7 days and 4 days. I’d like this one to be longer, but my birthday is next weekend and I couldn’t fast through my birthday! (I only get 1 real one every 4 years).
      Anyway, in my previous and current fasts, my family (wife and 2 kids) still eat. I help make some of the meals, and clean up almost all of them. Smelling good food is tough. Making food, and not being able to taste if the seasoning is right isn’t easy. Throwing out the last two bites on other plates instead of eating it while cleaning up bothers me. But I have done all that. Last night, I made icing and helped my 5yo daughter ice cupcakes – really wanted to lick the icing off my fingers a few times but I didn’t.
      During my 7 day fast 2 years ago, I was out shoveling snow multiple times. I went a little slower than I usually shovel, but was able to manage drinking water a few times throughout.
      This time, I drove an hour to school and back on Thursday (day 1 of fast) without many problems. I had headaches for the first 2 days, but that was probably from not preparing properly – lots of sugars and processed food right up to Wednesday night. Headaches are gone today.
      All that to say… based on my experiences, you can still do a water-only fast with family/kids and work, assuming work isn’t too strenuous. I’ve had a bit less energy than usual through days 2 and 3 this time, but I’m assuming I will be almost back to normal by day 4 or 5 based on past experience and all I’ve read… about the body using fats efficiently by that point (and I’ve got plenty for it to use).
      Let us know how it goes. (My previous 4-day was supposed to be 7-14, but I cut it early because I didn’t feel good on day 5, but that’s okay… that’s why I’m trying again now).

  85. China Richmond Avatar
    China Richmond

    Jason thank you so much for your detailed reply, knowing all of that is super useful and from your experience and Chris’s response it’s settled I’ll start with 2 days and then try increasing. I guess I got so excited to read all the benefits that I kind of thought 2 days wouldn’t really provide much change so headed to 7 days straight away in my head. I’ll psych myself up beforehand and perhaps try 2 days over the weekend so at least I don’t have to work and can hide as much as possible if I am struggling! Thanks again for your info 🙂

    1. Jason Kroeker Avatar
      Jason Kroeker

      I don’t want to discourage you from doing 2 days as that works for many people. But in my experience, since I am not normally on a keto diet, I find it very hard to get from the end of day 1 through day 3 as my body switches into ketogenesis. I didn’t use any salts or electrolytes so those would probably help from what I’ve read. But days 4 to 7 are the easiest (I’m starting day 7 now). I even played volleyball at the end of day 5, though I wasn’t at full energy, and sat out game 3 of a 5 game set because I was exhausted.
      When you are ready to do a longer one, I’d recommend Thursday dinner or Friday breakfast be your last meal, to hopefully be in full keto-mode by Monday for work.

  86. Von Avatar

    Thank you for this. I will do this tomorrow. I tried fasting for 2 days only the last time. And eventually went back to my horrible eating habit. This time will try 7 days. Hope I can go thru this until the end. Thanks for this article.

    1. Chris Avatar

      You’re welcome, Von. Thanks for the comment. Keep us posted with how it goes!

  87. jo Avatar

    I want to embark on a 21 day fast ive done a few 5 day and 7 day fasts but I feel that I am ready for a longer one. what different measures do I need to take on a longer fast

  88. Bethany Avatar

    Really appreciating your post on fasting thank you for that. I think you have missed a really important factor here though. The integration back into normal foods. It’s the most important part of the fast. It’s super important to build the micro biology in the gut. So your picture of you and your friend about to eat a big meal after your fast is very misleading. A 5 day integration period its most beneficial.

    1. Chris Avatar

      Hi Bethany. Thanks for pointing out that gap in this guide. You’re right! I’ve added a section on refeeding. Where have you learned that a 5-day integration period is most beneficial? And would it not depend on the duration of your fast? If you have resources to share on this, please do so I can update accordingly.

  89. Olayiwola Avatar

    Hello Chris, what’s lovely right up. My question is, as a female, is it advisable to fast when I’m menstruating?

    1. Chris Avatar

      Hello Olayiwola. Sorry, I haven’t the slightest idea. This post pushed my limited understanding and absent expertise about fasting to the edge. Pretending to know anything about menstruating would be jumping off the cliff.

      By the way, I first read your comment as saying, “What’s lovely?” as another way of saying “What’s up?” “What’s good?” or “How’s it going?” If even if you didn’t intend it, I love it. I’m going to start saying “What’s lovely?” to people I meet now. Thanks for that!

  90. Stephen Avatar

    2 Questions:
    1. Is now a bad time to start fasting? How does fasting affect your immune system?

    2. I want to take a multivitamin, but several vitamins are only fat-soluble, so I’m considering adding MCT oil/butter to my morning coffee to take with my vitamin to aid in nutrient uptake. I know MCT oil works well with keto, so would that also be ok with fasting? I know, perhaps it breaks the fast since it’s pretty calorie-dense, but I’m not fasting to lose weight and I doubt it will do much to help with hunger…I’m currently 38 hours in, and am not sure how long I’ll go. Jesus fasted for 40 days, so maybe I’ll give that a shot!

    1. Chris Avatar

      Hi Stephen.

      1. I don’t know about fasting’s effect on the immune system. If you’re reasonably healthy and taking precautions with avoiding getting viruses, I doubt fasting would affect your risk too much for better or for worse. The lockdown is a bigger deterrent for me. I’m finding it harder to fast when I can’t even leave my house.

      2. Go for it. Some say it won’t be a “pure” fast, but whatever. It bit of MCT oil isn’t too many calories and shouldn’t stimulate an insulin response. Check out what Valter Longo’s doing and you’ll see he’s finding people are benefitting while still consuming a controlled minimal dose of calories every day. If your first fast with some fat goes well, try another without it and see how/if it differs.

  91. Jock Avatar

    HI Chris, Thank you very much for the article and I found it super interesting. I am on day 5 of a water fast that was not planned. I am locked down and working long hours remotely due to COVID-19 and my wife was starting Ramadan so I figured that I would join her but do a pure water fast. I am interested to know if i should start drinking sea salt with water and or electrolytes. We are in Ukraine and I don’t speak Ukrainian so I think I’m going to have time finding electrolytes but I was wondering if there is any point in me starting now as I’m already fasting. I also had issues with sleeping the last few nights and it was waking up more than often but overall feel OK. Reading your article was very helpful and motivating and now I may aim for 2 weeks or longer depending on when the lock down here ends and I return to the office. So my questions are if there is any point to start salt in my water and if it is recommended to have some miso paste?

    1. Chris Avatar

      Hi Jock. I’d recommend you sprinkle some sea salt into your water to retain minerals. For sleeping, consider magnesium. You could look up the word in Ukrainian and find pills at any pharmacy.
      Your mention of Ukraine brought fond flashbacks of my visit there (Kiev and Odessa) about 9 years ago. Thanks!

  92. Ben Avatar

    Can i do 7-12 day water fast if i sepplement with some pink salt, lemon, apple cider, bakingsoda, and broth

    1. Chris Avatar

      Hey Ben. I don’t see why not. Let us know how it goes.

  93. Marcus Avatar

    Hi, what a great read!

    One aspect I often miss when talking about health and weight and especially losing weight is that as a very skinny person, I don’t know if it will suit me.

    I’m 42, I’ve been 185 cm’s and 62 kilos since I was 18. I don’t do sports but I exercise(usually running) a few times a week. I really DON’T want to lose any weight. Can I fast, and what should I keep in mind? Btw it doesn’t matter how much I eat and/or train, I can’t gain weight. I’ve tried.

    1. Chris Avatar

      Hi Marcus. Good question! Prefacing this with the caveat that I’m an unqualified bozo repeating what I’ve read and personal experiences, as long as you have some fat and your skinniness isn’t due to some medical or psychological condition, fasting shouldn’t hurt. Obviously you don’t need to do it as regularly or long as others with weight issues. Try for a day or two and listen to your body.

  94. Kady Avatar

    Quick question, how often do you do an extended fast?
    Say I wanted to try my first 3 day fast, how many times per month would you recommend I try it?
    I’ve done intermittent fasting and can easily do a 24 hour fast but I’m curious how many times a month you’d recommend?

    1. Chris Avatar

      Hi Kady. The useless but true answer is everyone’s different depending on their goals and lifestyle. I’d recommend trying the 3 days then going from there. If that goes well, consider extending it to 5. And when you feel you’re ready to go again, go for it. That’s how I approach it, at least. Let us know how it goes!

  95. Lester Villalvazo Avatar
    Lester Villalvazo

    Hi So I’ve faster for 8 days now why do I cramp up so much like my legs cramp up or the side of my stomach cramps up. Am I not drinking enough water do I need supplements?

    1. Chris Avatar

      Hi Lester. Sounds like you could be drinking too much water and not enough salt. Try some miso, bone broth, pickle juice, or sea salt. Hopefully that helps. If not, maybe it’s a sign to stop fasting.

  96. Omar Sigala Avatar
    Omar Sigala

    Hey Chris the article was great and I’ve been fasting for 8 days up to this point and this is my first time fasting and I did it cold turkey I usually eat like four meals a day and snack a lot too and I am 6’2 and 300 pounds but so far I find it really easy to do and can even exercise like normal such as play sports and lift weights without having problems and I feel great. My question is is that normal and is it because I’m a bigger guy. Also this eighth day I my last but I definitely want to fast again so how long should I wait until I fast again

    1. Chris Avatar

      Hey Omar. Wow, I can’t say I’ve heard of anyone who’s had such a smooth cold-turkey transition into fasting. Lucky you. Maybe there’s a fasting gene or something that you have, ha. As for when you can fast again, that depends on how you feel. If you feel great and people close to you (ideally a doctor, too) have no reason for concern, you can make it a routine—especially if you continue handling it so well.

  97. David Nour Avatar
    David Nour

    I have completed almost 3.5 days of a 5-day water fast. Nothing but water and a bit of salt and magnesium. I feel weak. My shoulder which has tendonitis is hurting. And my lungs hurt. I can’t sleep. Should I stop?

    1. Chris Avatar

      Hi David. Sounds like your experience is becoming quite miserable, so yeah I would stop if I was you. 3.5 days is already an accomplishment.

  98. Bonita Avatar

    Hi thanks for a great article . Hi am currently on day 2 of a 14 day fast . I have done 5 days before and coped well . My motivation is just giving my body a chance to reboot and also weight loss . I love my coffee and find it impossible enjoy it without my fat free/skimmed milk . Will this affect my weight loss a lot ? I am hoping to loose about 20 pounds . I know that’s not going to happen in 14 days , I am going to attempt intermittent fasting after my 14 day fast to loose the balance .

    1. Bonita Avatar

      Excuse the spelling it seems this lockdown has fried the brain !

      1. Chris Avatar

        Hi Bonita. Adding a bit of milk to your coffee won’t make much of a difference (…as long as you’re not having dozens of coffees with milk every day!). One consideration for your weight loss goals is to go full-fat. Fat doesn’t necessarily make you fat. And healthy fats, like those in cream, are better than many calories you might feel the urge to consume otherwise from processed carbs.
        Best of luck with your fast!

  99. Hope Avatar

    Hi Chris, Thanks for the simple straightforward article. I learned a lot. But I have a specific issue. I did a 3-day fast last month. Now I may try up to 30 days (min 5). My main reason for fasting is to heal my gut (and lose 30 lbs). Chronic bloating is my issue. Tonight completes day 3 and my bloating is not going away. You mentioned after 3 days you had a caved-in stomach. I’ve been on IF/Keto with TMAD for months. Before that I ate healthy but not perfect. I drink a lot of water (2-3L/day). And take a lot of supplements per my ND (stopped during fasting). I feel inflammation in my gut and hidden food sensitivities are the culprits. That’s why I’m fasting. Tbh my “water” is infused with electrolyte tea (no sugar no caffeine no calories) that I drink 4L/day. I’m really thirsty. I drink green tea with a pinch of stevia. And a 16oz water w/ ACV and lemon. I take colon cleanse herbs and magnesium at bedtime to ensure BMs. My question: why am still bloating? Too much water? detox symptom or healing crisis? my body needs more time to heal? Or the water additives cause bloating? Please advise or suggest links. Thanks in advance.

    1. Chris Avatar

      Hi Hope. I’m sorry to say I don’t know anything nor recall reading anything (at least anything memorable) about bloating, so I can’t help you with your question. And I’m sorry to hear it’s been such a tough nut to crack despite your impressive efforts. You’ve tried an elimination diet? That’s the only idea that comes to mind.
      If (or when, cuz it seems inevitable based on the effort you’re putting in) you find a fix, please let us know.

    2. Sid Avatar

      Hi Hope,
      I have exact same symptoms. I am also doing 3day water fast to get rid of this bloating issue and I am on my 2nd day today. My bloating hasn’t gone away. Please let us know if you have found anything useful.

      Thank you

  100. Alex Avatar

    I just want to let you know all ur articles are great (and fun to read!) . Anyways my question is do you know if taking Adderall and Ibuprofen will diminish all the effects of autophagy (I know taking Adderall sounds like cheating lol). I’ve been fasting for about 2 days and plan to go another couple days because my last 2 abs for the elusive 8 pack are almost visible! And of course to be health 🙂

    1. Chris Avatar

      Thanks Alex. I think you’re making a lot of other readers jealous with your almost 8-pack, haha. 6 isn’t enough for you? Good on ya, though.

      All the autophagy research seems uncertain and difficult to gauge in general, so I can’t imagine they’ve nailed down answers to specifics on Adderall and Ibuprofen yet. As you might have read, I wrote that I felt I was on Adderall on my first 3-day fast, so you question got me wonder what a double dose of powering it with a pill would feel like. I guess you’ll find out!

  101. Sess Avatar

    Hi Chris. Thanks for the great article! What do you think about fasting for those with eating disorders? I am trying to recover from bulimia, and I am thinking about fasting to heal all the inflammation and damage I have in my body. I am approaching it from a different mindset than that I had with my bulimia, but I am afraid I would relapse and binge! What are your thoughts on that? Thanks again 🙂

    1. Chris Avatar

      Hi Sess. Thanks for the kind words. And congrats on making progress recovering from bulimia. I already put myself out a bit too far on a limb with my unqualified answers to other questions here and for your the limb will certainly break because I know zero about eating disorders. You’re already being careful, which is about all I could say. Maybe start with studies like this one, then go through the articles that site it to see what other information is available?

  102. Steve Avatar

    Good stuff here. I am on day 13 of an “as long as I can last fast with a maximum of 40 days”, then onto a more healthy portion-controlled diet. I lost 9 Kg (19.8 pounds) in the first week but looks like being only 3 or 4 Kg when I weigh in tomorrow which means the first week was at least half water. (thanks for explaining that Chris) My starting weight was 135 Kg, close to 300 pounds, the goal is 100Kg 220 pounds. I feel about 90% most of the time although I am not experiencing the euphoria and increase in energy that some do. my job entails walking around a boat harbor each day which is about a 4 km walk and I am ready for a rest after that. I am amazed at my mental reaction to food though. When I see food at home or on tv I get a strong urge to eat it even though I am not the least hungry. I wonder if this is just a natural reaction as my body wants to get some calories or if its part of some sort of underlying food addiction. It is so weird and the feeling is so intense. I fell I am actually scared to eat something now, and I hope I dont feel like that at the end of the fast! This site have been very helpful so thanks so much for putting it up.

    1. Chris Avatar

      Hi Steve. That’s interesting that you feel such an urge to eat but not actually hungry. It’s almost as if you’ve become conscious of the difference between hormonal drivers and actual physical needs. Maybe that’s a good thing? Sure, you’ll naturally be raging for food when you eat again, but as long as you can keep this consciousness you’ve developed, you’ll be better able to control yourself, no?

  103. Steph V Avatar
    Steph V

    Hi Chris,
    Thank you so much for this invaluable source of information. Your writing is great: clear and useful and interesting.
    Question: if one avoids deliberate exercise (sticking solely to the inherent movement of necessary day-to-day activities and work), do you think it is safe to not take electrolytes on a prolonged (5-7 day) fast? And just stick to filtered water.
    Thanks in advance, Stephanie

    1. Chris Avatar

      Hi Steph. You lose electrolytes in your urine, so even if you don’t sweat I’d recommend replenishing them. You won’t die without them for 5-7 days (but please don’t let your family sue me if you do). From my experience, you feel much better by taking them. If you decide go added-electrolyte-free, be careful not to over-dilute yourself by drinking (and thus peeing) too much.
      All the best and let us know how it goes!

  104. Julie Horst Avatar
    Julie Horst

    Good news. I am in a cabin. No access to food. Broke a 5 day water fast.
    In cabin only find dried apricots and fish. Had some apricots with my tea. Is it ok to take a little fish later. Hope I do not have stomach problems.
    Kindly reply asap.

  105. Julie Horst Avatar
    Julie Horst

    Interesting facts about water fasting. Have fasted for years.

  106. Phin Avatar

    I started water fasting. There was almost no hunger after the first 24 hours. Somehow I started with heavy diarrhea, any water I drank (which was a lot) would come out. By the 45 hour point it was so bad it came out five minutes after drinking it. I broke the fast with bone broth, which didn’t stay more than 5 minutes. So I ate white rice and a banana. That was last night. Today I woke up super early with lots of energy!
    Has anybody had this “situation” while water fasting?

    1. Chris Avatar

      Hi Phin. I haven’t heard or read of such an “explosive” response, but I don’t doubt you’re alone. Anyone else who reads this and has had similar experiences, please share.

      Sounds like you did the right thing to have bone broth and eat. And good to hear that you feel great after. Hopefully next time the fast will be a bit more… solid.

      1. vaibhav t Avatar
        vaibhav t

        Yes me, I’ve tried the OMAD diet last week, I got dirrhea the first day. I took ISABGOL and continued with fasting.

        Although to note, I have a lot of gut problems(which led to Akylosing spondalitis)

        1. Chris Avatar

          Good to know Vaibhav (about the Isabgol, not so much your diarrhea.)

          To anyone like me who’s not heard of Isabgol, it’s Psyllium husk.

  107. Nat Avatar

    Thanks for the tips – currently finishing day 3 of 8 and really struggled today. This post has given me more motivation to continue tomorrow 🙂

    1. Chris Avatar

      Awesome, Nat. By now it’s be Day 7. Hopefully you’re doing well. One day to go!

  108. Amy Avatar

    Hi Chris!

    Great article! I’m trying to help my husband improve his health. I want to suggest fasting to him, but his job is high stress and can require strenuous exercise without notice at any time. I’m concerned about him fasting at work. (He only has 2 days off at a time.) Do you have any suggestions for people who do strenuous, unpredictable work like fire fighters, police officers, and paramedics?

    1. Chris Avatar

      Hi Amy. Tough question! Fasting seems like it might be a bit too much for your husband to get straight into. Possibly dangerous like you suggest. I’d suggest starting with helping him improve his health by improving his diet, regardless of how often he eats. Less processed carbs, in particular. If he can do that and still needs health improvements, reduce snacks. Then if he’s still going strong, fewer meals. Then fasting if he’s still going strong.

  109. Taisya Avatar

    This blog was so good! I read through a bunch the commments and didn’t see this same question so if you have answered it before sorry for the repeat. I’ve been fasting 7 days on – 7 days off for the last 3-4 or so months and have lost about 20 kilos all up. I’ve only ever drank water during a fast because I’ve been panicked that anything else will take me out of ketosis. But if I drink green tea or chicken broth it won’t take me out of ketosis? ALso (because I’m really not a fan of tea) is there any sweetener of sort I can add to the tea that also won’t take me out of ketosis? Maybe like erythriol because the body doesn’t absorb it? I couldn’t find any information on any of this anywhere else online so thank you in andvance 🙂

  110. Chris Avatar

    Wow, amazing work, Taisya! Since you’re so hardcore, you may want to consider getting something that can measure your ketones for you. That way you can experiment with small amounts of anything, see how your body reacts, then adjust accordingly. I don’t have any device to recommend, but I’m sure you can find some good recommendations online.
    Tea has no calories so it won’t bring you out of ketsosis. Broth has no sugar, so won’t either. Instead of sweetners, maybe try a spice like cinnamon or nutmeg? Or vanilla? We associate these tastes with sweetness even though they don’t have any calories.
    I hope that helps. All the best!

  111. Phin Avatar

    Hi again!
    About my last post, I think I identified the problem. I saw many videos and websites that spoke about taking salt in the water, as to retain water, not to dehydrate and as electrolytes. Looks like I was taking too much salt and that caused the “explosive” reaction. (Salt Water causes purge). Since then I have fasted 48 hours once or twice a week with no problems! (Taking water with potassium and magnesium supplements).

    I am finding myself in a quarry, first time I fasted I lost around 3 pounds. Since then even though I have fasted “a lot“, I haven’t seen more weight loss.

    Also, I have noticed “muscle loss” around 1 pound… since I started fasting (according to my scale).

    I am getting a little cold feet on my fasting… any suggestions?

    1. Chris Avatar

      Hi Phin. Thanks for sharing your discovery that too much salt is kind of like adding baking soda to coke. How much salt were you adding? More than just a sprinkle, I imagine.
      On your weight questions. How can your scale measure muscle loss? I wouldn’t get to caught up with such a rough measurement. Maybe even consider a DEXA scan? And when you say you lost 3 pounds on your first fast, how much of that is water?
      Honestly, my advice would be to not get too fixated on the numbers, especially with imprecise and possibly misleading measurement. How do you feel? Has fasting affected your “addiction” to food? Do you feel sharper when fasting? Less lethargic?

  112. Tabitha Zapata Avatar
    Tabitha Zapata

    Hi! I started a 21 day liquid fast. This page is very helpful, even the comments were helpful!!!! Thanks for replying to everyone.

    1. Chris Avatar

      Thanks Tabitha. Here’s hoping you keep up that enthusiasm! All the best.

  113. Tunmise Avatar

    Hi Chris, Thanks for this amazing article, I found it super helpful and really insightful. I had previously read articles about how long the body to lose the carbs and sugar before actual weight lose begins. I’m about to start a 21-day water fast, but I was thinking of making first 2 days a dry fast so as to get to the actually fat burning/weight loss asap, instead of the regular 5 days it’d probably take if I were water fasting. What are thoughts on this please?

    1. Chris Avatar

      Hi Tunmise. Even in your first days of burning out the sugars from your body you are losing weight. All calories, whether fat or carbs or protein, count toward 3,500 calories per lb. And a dry fast won’t get you into “fat burning mode” any faster. If you want to burn calories faster, you can exercise. Just make sure to stay hydrated and replenish your electrolytes.

  114. Henry C Avatar
    Henry C

    HI Chris!
    What a wonderful write-up!
    I tried to fast for three days, but on the second day I felt a bad pain in my stomach that forced me to stop, do know what might be the cause?
    #Please reply
    #have a wonderful day

    1. Chris Avatar

      Hi Henry. I don’t know enough to speculate on what could have caused your stomach pain. As you might have read in the comments, everyone reacts differently. You made it to day 2, which is pretty good for a first-timer. Congrats. Hopefully the pain wasn’t so bad as to make you never want to try again. And hopefully next time the pain doesn’t come back.

      1. Henry C Avatar
        Henry C

        It’s amazing how you find enough time to reply everyone’s comments…
        People like you are really hard to find!!!
        Thanks for the reply!

  115. Ari Avatar

    Hi I am helping a family member who is working to control blood sugar and reverse T2 diabetes with extended fasts, she has read a lot that Jason Fung has on the subject. She would like to find a solid support group to join to help her when she needs a lift, share questions and have someone to communicate with when she is feeling challenged to continue a fast. Do you know of any good resources esp in NYC?

    1. Chris Avatar

      Good question, Ari. I don’t know. Have you searched for Facebook groups on fasting and/or T2 diabetes support? If you find something, please share with everyone else here.

  116. Sammi Avatar

    I’m not sure if you still are on this blog but I’m on day 4 of my 7 days fast and I think today has been real bad, my stomach hurts a lot and I couldn’t even walk up the stairs… but then it goes away and I’m fine, I’m under 18 and I don’t find this horrible it’s just a little struggle hear and there… what do I do on day 7? Should I eat fruit? What should I stay away from? Thank you!

    1. Chris Avatar

      Hi Sammi. I’m sorry to hear about your sometimes painful fasting experience. Please be careful and listen to your body. Speaking of being careful, good question. The section above titled, “How should I break my fast?” has some tips.

  117. Jen Avatar

    Hi Chris! This is article is the first I’ve read on your site and I looking forward to be binge-reading this weekend!! This article was great – thank you so much for all the work in putting it together. And two years later you’re still responding to people’s comments?!? That’s amazing!! To me, that really shows how much you care and I’m super impressed! I’ve been a Jason Fung follower for a few years now. As I write this, I’m on day 5 of what I hope to be a 21 or 30 day fast. I’ve done two 7 day fasts before this and several 3 days and lots of intermittent fasting. I’d love to get your input or opinion on something. Everyone talks about this laser focus clarity they feel in their brain while fasting as you mentioned in your article. I don’t really feel like I get that benefit so much. Now, to be sure, I feel much better! I have an extreme sweet tooth, it’s awful – and sugar makes me legit crazy. Like emotional, crabby, can’t think straight, a total beast. All of that goes away when I fast – it probably would if I went no-sugar too but I can’t seem to control my eating unless I’m fasting. So I feel better, but not that amazing feeling everyone talks about – any ideas why that could be? Is it just my brain? Or maybe it’ll kick in later in the fast?

  118. Chris Avatar

    Hi Jen. Thanks!
    Kim and a couple of my other friends who fast also say they don’t get the same Adderall-like mental boost from fasting. Recently, I haven’t so much, either. No idea why. I doubt you’ll get it by fasting longer. Maybe a bit if you stop craving food, so you can focus on your task at hand. But at least you get good mood benefits, right? That’s a pretty significant bonus.
    Best of luck with your super-extended fast. Let us know if you crack into some laser focus clarity.

  119. Muhammed Ali Ayyıldız Avatar
    Muhammed Ali Ayyıldız

    Hi chris , i couldn’t find anything about enema. Should i do enema while water fasting ? Some people say that it’s something that you absolutely gotta do but i don’t think that it’s such a big deal. What do you think ? If it’s okay to answer did you do enema while fasting ? (Beside chris everyone can answer it would be better to hear some more thoughts about enema while fasting )

    1. Chris Avatar

      Hi Muhammed. I haven’t researched the pros/cons of doing an enema while fasting. Why do some people say you absolutely gotta do them while fasting? Many—most, I imagine—don’t and still benefit, so it’s far from a must. I’m not interested enough to look it up myself, but I’d be curious to hear the arguments for it.

      1. Muhammed Ali Ayyıldız Avatar
        Muhammed Ali Ayyıldız

        thanks man i am starting tomorrow after this it’s a big relief for me to know that it is not something i must do and also keep on good working you are great , answering people after 2 years you are a different person

        1. Chris Avatar

          Thanks man. I’m glad you appreciate my input! All the best.

  120. Joseph Avatar

    hey chris i am on my day three of water fasting and i am feeling exahusted i am spendin my time in bed and sometimes my body get hot is it something expected to be like this on day three maybe my body haven’t started to use fat as energy resource?

    1. Chris Avatar

      Hey Joseph. It’s been a few days since your comment. How’d it go? Yeah, it sounds like your body was having a tough time going cold turkey on food and transitioning fuel sources. It happens to a lot of people, especially in their first fasts. My fiancee, Kim, for example. Sometimes it helps to take it easy and work your way up to longer fasts. But some manage to push through. Whatever works for you, hopefully it’s overall a positive experience.

  121. t.n. Avatar

    I have a question about mineral water during fasting periods. I tried to search to see if this was specifically covered and did not see it straight out answer.
    Will drinking carbonated mineral water (no flavors, no calories, just straight out natural mineral water) affect my fast?

    1. Chris Avatar

      Hi T.N. Go for it. Carbonated mineral water’s one of my favorite simple pleasures while fasting. Sometimes with lemon and salt, too. Or even cayenne.

  122. Vasco de Almeida Flamengo Avatar
    Vasco de Almeida Flamengo

    Can i do 5 days water fast um my first fast?
    I am Addicted to sugar ….

    1. Chris Avatar

      Hi Vasco. You can if it works for you. Lots of people do, especially sick people who have a lot of urgency. Depends on your situation and the severity of your addiction. Even half a day or a full day can be a great start. You can extend it from there. Whatever you end up doing, good luck cracking that habit!

  123. Nana Avatar

    Wow i cant believe so many people have actually successfully done it for up to a week or longer!! I’ve been stuck at 2 days the last time & most recently at less than 1 day! At the end of both times, I felt unbelievably dizzy, almost passing out, my body shaked….& even felt suffocated. Why is that I wonder? Any tips? I really would like to get to 4 days at least. Thanks for any advice in advance

    1. Chris Avatar

      Hi Nana. Yeah, it’s incredible what some of the people who’ve commented have done.
      In your case, tough to say since A) I’m no expert and B) I don’t know your background. Could it maybe be hydration (not just waters, but salts, too)? Maybe consider a ketogenic diet for, say, a week, then go into fasting from there to see how that goes? That could help with the transition since your body will already be fat adapted.
      Keep me posted on how you progress. All the best.

  124. phil Avatar

    Hi Chris,

    Phenomenal article: most likely the best I have seen. May i ask you three questions. Can i take my vitamins on a fast, will it hurt me or slow down weight loss? I know sometimes answer are not binary, but I am looking for yes or no, or mroee definitive answers.

    second question. can i do a 7 day fast, east for 1 or 2, and then continue with another 7. so 7 on 2 off?

    three: I am on phentramine, will that interfere or is it dangerous?

  125. phil Avatar

    Chris, first off, my apologies for previous spelling and grammar; I typed quickly.

    I have two more questions.

    1. if I have a package of top ramen ( just seasoning) once a week, will that be okay,? I know it has tons of salt, so I worry it will make me retain water big time.

    2. I want to clarify, above, why I like 7 on 2 off. It gives me a bit of a break and will allow me to do a much longer fast ( which I need due to massive weight). Would it be better to do 15 days and then 2 off? Any advice, or should I do the whole thing? I am shooting for 45 days. I am doing blood work.

    3. I do not touch salt, other than potentially soup broth ( rarely).

    4. I feel taking vitamins is very healthy and makes certain I do not bet into trouble, any problems?

    5. I am doing this fast for weight-loss reasons (100%) and of course I know benefits will follow.

    1. Chris Avatar

      Hi Phil,
      1. Vitamins. Take ’em.
      2. Fast as much as feels right. Consult a doctor if you want to go so intense. Dr. Fung follows similar protocols to the one you suggest with his most serious cases.
      3. Phentramine. No idea. Be careful.
      4. Try the ramen stuff once. See how you feel. Judge based on the color of your piss.
      Sounds like you’re really serious about go hard with fasting, which is commendable. And you’re asking the right questions. Take care, consult an expert (which I’m not), and all the best!

  126. phil Avatar

    Hi Chris,

    thanks for the answers, you are the best! Clarification: are saying Fung does talk about 7 on 2 off, or 100 on 2 off sort of idea? I have not seen that.

    So far, I am down 30 pounds. The only thing I do not like about taking breaks is that you have to restart the autography process ( takes about two days)

    1. Chris Avatar

      Hi Phil. Fung writes a bit about his experience with some of these fasting protocols in his book. Not a ton, though. And not 100 days on (!).
      I hear you on the autophagy concerns. (Funny typo you made, btw.) On the bright side, don’t you think there’s a benefit to training your body to flip back and forth from different fuel sources? For me, I feel it and it’s a big reason I regularly do short fasts.
      Way to go on dropping 30lb! All the best continuing your progress.

      1. phil Avatar

        Thanks Chris, I am notorious for typo’s- lol

        I agree with you. I think doing longer fats and then eating is much easier, however. I find that for every cheat day, i stop the clock for at 2-3 days (autophagy).

        I appreciate your help and support!


  127. Mike Avatar

    Great article. I have done a 10 day water fast. Last 4 days had 2 bananas daily for Spaciness.

    The electrolyte protocol might keep me to water only.

    Found that the real test was the food intake on day 11. I did eat a pre fast normal breakfast. Was belly ached for an hour them business as usual.

    Question. What is you longest fast?

    How far apart do you go between fasting?

    How cranky, 1-10, did you get and what day in the fast were you.?

    Thank you for your time.


    1. Chris Avatar

      Thanks Mike. My longest fast is 5 days. Puny compared to many others who’ve commented here. But huge compared to most people who can’t skip a meal without losing their minds.
      On spacing, I try to do a couple 3-5 day fasts a year and 46-hour fasts every 2 to 3 weeks—the latter to keep my body from falling into a routine of eating more than anything. I’m happy with my health, so don’t feel the need for any more than that.
      On crankiness, I feel crankier when I’m not fasting and feel hungry for whatever reason (which doesn’t happen much, fortunately) than I do when I’m fasting.
      Everyone’s experience and perspective’s a bit different, of course. Hopefully mine helps.

  128. Henry c Avatar
    Henry c

    Hi Chris, Please how can I gain concentration when fasting. I find it hard to read/study when fasting…

    1. Chris Avatar

      Hi Henry. You’re having a hard time concentrating because you’re so hungry? Maybe try some tea spiced with cayenne or cinnamon (or another spice that feels filling).

  129. Chloe Avatar

    “Sorry ladies, you cat use ‘its bad for women as an excuse'”. LOL at the irritating smugness of this post. Why would anyone need an excuse- especially from you? You’re not a doctor, and there are legitimate concerns about the safety and efficacy of fasting for women. Dismissing it as an excuse is pretty arrogant, gross, and even misogynistic. Anyone. I’ll make sure not to use any affiliate links or recommend this to anyone. How trashy.

    1. Chris Avatar

      Hi Chloe. Some people, myself included, tend to look for excuses for not doing things they don’t want to do but know they should should. That’s all I was referring to.

    2. Jess Avatar

      Thanks for pointing this out. That didn’t settle well with me when I read it, as I’m sure happened with many other people.

  130. Werner Avatar

    Fasting is an integral part of my life, even though my last fast has been a few years.
    After a four week fast I had to force myself to start eating again, as I didn’t want to lose the momentum of clarity in my mind, soul and spirit.
    One feedback for breaking a longer fast: start with eating popcorn! It’s the best way for me

    1. Chris Avatar

      Popcorn! Interesting tip, Werner. Thanks. Plain popcorn I guess? I imagine going crazy with seasonings and butter might be harder to stomach.

  131. Heather Christopher Avatar
    Heather Christopher

    Thank you for this article. Layman’s terms. I’ve been experimenting with fasting the last few months, and I can attest to the benefits. You helped me to clarify key issues that I have struggled with, such as the importance of electrolytes. As I reflect on my experience, yours helps me make sense of it. Also all research I’ve read has been from nutritionists and doctors, not someone who has practiced it. It really is in the mind… helps re-set mental focus…. really does help your entire being re-generate, not just the body. If someone wants to get healthy they must start with self-control; fasting fast-fowards the maintaining discipline hurdle. Thanks for simplifying what is perceived as difficult. Like with anything else, it takes practice.

    1. Chris Avatar

      Thank you, Healther. I really like how you put it:

      Fasting fast-forwards discipline.

      That’s it! And I think putting it that way may help other people who perceive fasting as difficult understand its value, give it a go, and realize the truth to what you say.

      Good stuff. Happy super-speed-self-disciplining, a.k.a. fasting!

  132. Alana Avatar

    Hi Chris.
    Currently I am 118 hours in of a 7 day water fast. I stepped on my omron scale, providing a full body scan.
    I am 5’5″ staring at 141.8lbs, 32.4% muscle, 27.2% fat
    This morning at day 5, 132.2lbs, 30.4% muscle, 29.1% fat
    141.4lbs x 32.4% muscle = 45.81lbs of muscle
    141.4lbs x 27.2% fat = 38.46lbs of fat
    On day 5 –
    132.2 lbs x 30.4% muscle = 40.19lbs of muscle
    132.2 lbs x 29.1% fat = 38.46lbs of fat
    Weight 141.8lbs – 132.2lbs = 9.6lbs loss
    Muscle 45.81lbs – 40.19lbs = 5.62lbs loss
    Fat 38.46lbs – 38.46lbs = 0 A BIG FAT ZERO!!
    I am using ketosis test strips, showing a very large amount. I walked for 20 minutes on day 1 and 2 only. I am fasting for 3 reasons, to heal from a pelvic tilt (reduce inflammation), to lose body fat, and for mental clarity. Everyday I take a multi vitamin, drink mineral water, and add salt occasionally.

    When does the body kick into fat burning? Am I even using the correct logic to calculate my results to date? Am I missing a calculation? My BMI has dropped by 0.6% approximately. My father says I should shoot for 14 days instead so the effort is not all for not.
    I plan to continue to monitor the indicators, and will go to 7 days because that was my mind is set on, but losing 5.62lbs of muscle mass, assuming the rest of the loss is 3.98lbs of water weight, and no fat is disheartening. 14 days seems daunting, as 7 days was daunting enough.

    What are your thoughts?

    1. Chris Avatar

      Hi Alana. As an ex-Finance guy, I love all these numbers… though not so much the story they’re telling, which as you say seem disheartening. Almost certainly, it’s an issue with your scale. Our bodies haven’t evolved to eat muscle before fat when in need of energy. Imagine if that were the case. We’d turn into blobs of bone and fat from starvation. Funny to imagine, but impossible. I suggest you see what your scale says the day after refeeding. Maybe the water-loss from fasting is throwing it off. Or try a DEXA scan. Or trust your gut (and how it looks in the mirror) over the imprecise measures you’re getting. As for 7 vs 14 days. 7 days is freaking incredible. Way to go.

  133. Mandy Avatar