water fasting tips cover image of an empty plate and glass of water
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 About Fasting

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.

Here you’ll find answers to questions I once had and am now often asked. It’s written in easy-to-understand normal people’s English—not over-complicated doctor talk—but the scientific info here does come from a doctor, Dr. Jason Fung. His 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.

Because the more you understand fasting and how and why to do it, the better your experience will be, the more likely you’ll do it again, and the more you’ll benefit.

Don’t be stupid like me.

Water Fasting Tips


Who are you and why should I trust your water fasting tips?

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. Now I 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.

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 commision 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 ten hours making this post, not to mention the time I spent reading his book, taking notes, and experimenting with fasting, 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.

If you want to check out the book without giving me a commission, here’s a non-affiliate Amazon link.

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.

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 on medication.

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.

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.

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. Just check Amazon or your local pharmacy for whatever looks good to you.

Reader Tip: As a cheap, easy, and vegan alternative to bone broth, go to a Japanese grocery store and get some instant miso soup packets.

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.

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.
  • 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

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.

Will my before and after photos blow my mind (and my friends' minds too)?

Yeah. You won’t believe it

And by, “won’t believe it,” I mean, you won’t believe how much you look the same.

Sorry to ruin your dreams, but here’s the reality: You can only expect to burn half a pound of fat (3,500 calories) a day while fasting. The average human weighs 137 pounds and has about 25% body fat, which means they have 34 pounds of fat to burn. If we assume it takes you two days to burn off the food and sugars in your body and start burning fat, and you do a five-day fast, that means you’ll burn 1.5 pounds of fat. That’s only 4.4% of an average human’s body fat.

You will notice some visual differences though. 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.

The real benefits are long-term. And if you keep it up, and continue with a healthy diet, you will eventually have before and after photos that will truly blow your mind (in a good way).

Understanding and Fighting Hunger

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 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.

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

Click here to leave your question in the comments below so others can see. Or, if you’re shy, send me your question privately with this form.

If you found this post helpful or useful, please don’t keep it to yourself and share it with others!

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  1. 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. 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.

  2. 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. 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. 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. 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.)

  4. 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. 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.

  5. 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. 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.

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