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.
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 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.
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.
- 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.
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.
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
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:
Break your fast. You’ll get ’em next time.
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.
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.
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.
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:
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.
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?
Ask away in the comments below and I’ll get back to you as soon as possible and add to this list of water fasting tips accordingly.
Thanks for reading and thanks in advance for your comment!