DISCLAIMER: Please consult your doctor before trying fasting. It may not be safe for everyone.
A couple of weeks ago I did a 24-hour fast. I do one four times per year, with the changing of the seasons.
I did not do this as part of a diet or to lose weight. I’m quite skinny already, and fasting isn’t a good weight-loss strategy. (Nor is dieting in general, for that matter.)
So why would I do such a thing? Why would I deny myself access to delicious and nutritious food for a whole day?
I have a good reason, five reasons actually. Here they are.
1. Brain Health
Many people fast for their physical health, and I can’t really speak to whether or not that’s a good idea. I’m not concerned with my physical health, which is quite good – I’m concerned with my brain health.
Long-time readers will know that I’m pretty obsessed with brain health. It’s the main reason I exercise. It’s how I choose what to eat and why I mostly avoid sugar. It’s why I prioritize quality sleep.
Well, last year, I learned about something called the “glymphatic system,” which is how your brain cleans house at night. (See this blog for details.) The brain-flushing process requires a lot of blood, so if you eat near bedtime, you won’t have enough blood available to get a proper cleaning because your body will be focused on digestion.1
The solution? Don’t eat within four hours of bedtime. Last fall, I adopted that practice, and it triggered a cascade of benefits: more energy, more willpower, clearer thinking, and so on.
But I also wanted to make sure I was getting a really good brain flush every now and then, so I adopted the practice of fasting once per season.
Furthermore, renowned brain-health expert Dr. David Perlmutter, recommends fasting once per season for a different reason. In Brain Maker
, he explains how occasional fasting supports your gut’s microbiome, which, in turn, improves your brain function due to the fact that most of your neurotransmitters are manufactured in your gut.2
2. Willpower Training
Another reason I fast is for willpower training. The brain is like a bunch of muscles, and willpower is one of them. Muscles get stronger when they’re challenged, and resisting the temptation to eat when you’re hungry is, well, challenging. And that’s just one of the ways that using willpower generates more willpower.
This goal is actually connected to the goal I mentioned earlier – of not eating before bedtime. If I can muster the willpower to avoid food for 24 hours, then surely I have enough strength to resist food for the four hours between dinner and bedtime.
And using fasting as willpower training isn’t anything new. I once read about a Native American tribe in which some members would routinely fast, not because they didn’t have food, but because they wanted to develop stronger willpower.3 The Stoics of ancient Rome did it too. Fasting can be a self-imposed challenge used to cultivate mental toughness.
On a highly related note, I also fast to increase my tolerance of discomfort.
3. Discomfort Training
I once wrote about the value of discomfort training – deliberately putting yourself through uncomfortable situations in order to become better at handling discomfort, pain, annoyance, and frustration in the future. For a small, daily dose of discomfort, I start my shower with cold water. For a larger dose, I might climb a mountain.
By choosing discomfort on purpose from time to time, I’ve gotten much better at accepting discomfort that I didn’t choose. When something unpleasant happens, I can maintain my equanimity better because I’ve practiced tolerating unpleasantness many times.
Fasting for 24 hours really isn’t terribly hard, but it can be uncomfortable. Hunger, after all, is a feeling that evolved to be uncomfortable enough to motivate you to go find food. And since there is food in my home, I could easily alleviate that discomfort by walking to the kitchen and grabbing a snack. Instead, by choosing to sit with it, rather than act on it, I’m improving my relationship to discomfort.
And, more specifically, I’m improving my relationship to hunger.
4. Improve Your Relationship With Hunger
Hunger can make you feel a sense of urgency. When I feel hungry, something deep in my nature tells me to go get food. Right now.
But fasting shows you that this is a false sense of urgency. You don’t have to react to it. You can just sit with it. You feel hungry, but you don’t seek out food, and nothing bad happens.
In fact, you’ll discover that hunger comes and goes. It’s not constant. It comes in waves. When you feel seriously, even desperately hungry, ride it out. Soon enough, the craving will pass, and you won’t even notice your hunger anymore. It’ll come back later, probably a little stronger, but you can ride the next wave too.
Well-fed westerners often exaggerate their state of need when they’ve gone six or eight hours without a meal, saying “I’m starving!” when really, they’re a long way from starving. This exaggerated language doesn’t help you stay calm and collected while you wait for food, it amplifies the false sense of urgency, and it’s downright insulting to anyone who is actually starving, which brings us to our final reason to try fasting.
5. Empathy For Real Hunger
There are people in the world who experience real hunger. They go without food, not by choice, but due to misfortune. And it’s very easy to ignore this tragic reality. And if you’ve never gone without food for a day, it’s very hard to even begin to imagine what that feels like. So another reason to fast is to develop better empathy for real hunger. Maybe it will inspire you to give to charity or volunteer at your local food bank.
Many of us were told, as children, that you had to “clean your plate because there are starving children in Africa.” Well, I fail to see how American kids eating more than enough calories is going to help any of the starving kids in Africa. But if we occasionally did the opposite and went without any food on our plates, we might develop enough empathy for those kids to actually do something about famine.
Tips For Doing a 24-Hour Fast
Perhaps now you’re ready to give fasting a try. You might want to adopt a few strategies to ensure a smoother first-time fast.
True, all you have to do is not eat. There’s nothing complicated about it. But fasting is a great example of something that is simple but not easy. In fact, one of the main reasons to do it is that it’s hard.
But that doesn’t mean you can’t set yourself up for success, especially when you’re a beginner.
The first thing I would suggest is to choose the timing of this willpower battle wisely. Don’t schedule your fast to coincide with a holiday feast or a friend’s BBQ. Don’t schedule it for a day when you’re planning to run ten miles or climb a mountain. Don’t schedule it on a day when you’re going to be swamped with high-stress work.
When I fast, success is going a full 24 hours without eating and skipping three meals. I recommend eating a hearty, late breakfast, and then fasting until lunch the following day. That way, you’re asleep for most of the hard part, and you take full advantage of sleeping on an empty stomach. Powering through the morning isn’t too hard. I just get a little exercise, drink a little coffee, meditate, and get to work.
Don’t go grocery shopping – too tempting. Keep food out of sight and out of mind. Hang out in parts of the house that don’t have food. If your office normally has snacks stashed in it, move them. Stay out of the kitchen. And for the love of God, don’t open the fridge or the pantry.
If you’re feeling tempted, go for a walk. If you feel like chewing something, chew some gum. If you want to experience a flavor change, drink some tea. If need be, distract yourself with a movie or a project.
Don’t be afraid to get a little exercise. When our hunter-gatherer ancestors were hungry, they didn’t just sit around waiting for food to show up – they had to, well, hunt and gather, which was exercise. In other words, we evolved to be perfectly capable of moving our bodies on an empty stomach. Now, you probably shouldn’t go for a 40-mile bike ride while fasting, but you can do a moderate workout.
And again, please consult your doctor.
Non Appetit!
1 Gundry, Steven R., MD. The Longevity Paradox: How to Die Young at a Ripe Old Age (The Plant Paradox)
. Harper Wave, 2019.
2 Perlmutter, David, M.D. Brain Maker: The Power of Gut Microbes to Heal and Protect Your Brain for Life. Little, Brown, 2015.
3 Sadly, I can’t remember where I read about the Native American fasting practice … maybe 1491: New Revelations of the Americas Before Columbus
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