How Fasting Enhances Your Body’s Health

Down to the cellular level, the way that we nourish (or fail to nourish) our bodies is often times looked to as the single most important determinant of most everything attached to health. Even in the womb, the mother’s diet influences the child’s development on a genetic level. Yet the time we spend performing the actual act of eating is quite finite: roughly one of our 24 hours… 


The Other 23 Hours

You might have heard the Debussy quote "music is the space between the notes." Likewise, it's an obvious, if easily forgotten, maxim that the bad times give meaning to the good. We all understand the importance of contrast. Yet here we sit, amidst the relentless torrent of new fad diets and those “thought leaders” with their tireless fixation on the ritualistic posting of the new favorite kale smoothie picture on social media.

If eating takes up only about one of our 24 hours, it seems the other 23 hours don’t get a whole lot of attention. Yet recently, more and more research is supporting the reality that applying some intention to the way those 23 hours are organized can make just as much difference to your overall health as what you’re actually eating.


Good Stress vs. Bad Stress

By now, the idea of “good stress” and “bad stress” has permeated our cultural psyche. You’ve probably heard some version of the adage that bad stress kills you, and good stress makes you stronger. If this idea is new to you however, take a peek at this TED talk. It’s a very general summary, but actually pretty brilliant (though not half as brilliant as the speaker’s book which, in my opinion, should be required reading for humanity).   

But that whole paradigm doesn’t even go far enough. This idea not only applies to stressful life events and stressful situations, but even to things that generate a more basal variety of stress: being too hot, being too cold, exercising, and, most importantly for our illustrative purposes, being hungry.

Our bodies are built to withstand stress. For all the incredible complexity that is every single human being, our bodies have to be exceptional at keeping all the important bits in working order. Working backwards: Literally everything is a stressful threat to the survival of a single-celled organism. Not too long ago (on a cosmic time scale), we were that tiny, single-celled organism. We are essentially protozoa that have just gotten really, really good at being stressed out.

Today we are in the midst of the most ambitious experiment ever witnessed by organic life on Earth: We have taken that little protozoa species that got really, really good at dealing with stress (yep, I’m still referring to us), and removed 90% of the stress that brought us into existence. Based on systemically rising rates of diet-associated disease, I am genuinely concerned for the legacy of those little evolved protozoa. At the moment, this experiment isn’t looking so promising.


The Other Side Of Stress (Or Hunger)

So, what science is starting to understand with continuously greater depth is that the body needs to be stressed. Humans deal with being a bit stressed out infinitely better than we deal with not being stressed at all. (Though if you think about it, the fact that our biology drives us compulsively to make decisions that alleviate stress seems like either a significant design flaw or a cosmic joke.) 

The interesting other side of all this is the idea that, in many ways, the human body actually prefers being hungry. I mean in almost every way, your body prefers to be hungry. When you are in a fasted state almost everything works better than if you had a full belly.

To start with, your brain works better. After the body uses up all the carbs at its disposal from your last few meals, it switches to using fat. It is the process of using your body's stored fatty acid that gets you a bump in brain function. Your body turns fat into ketones and uses that as the primary power source. Your body typically runs off glucose that is made from carbohydrates with a little help from your digestive tract. Think of it like this: If glucose is a bag of green tea from a cheap box store, then ketones are organic kabuse sencha green tea purchased 30 yards from where it was grown on Kyoto island.  Big difference.

In the land of the immune system, the most concretely demonstrated effect is actually highlighted in cancer patients undergoing chemotherapy treatment. When one fasts while undergoing chemotherapy, the degree to which the immune system is suppressed gets reduced significantly. This is important for anyone who is battling cancer of course, but let's draw that line of logic out a bit: If the immune system becomes more durable to outside stressors, even ones as intense as chemo, it follows that with or without cancer, the immune system is overall operating on a significantly higher lever.

Over all, your brain works better, your blood pressure goes down, and you handle other stress more effectively as a result. Fasting kicks your immune system up about four notches, it helps your body slough off cells that aren’t working properly (e.g., cancer cells), and it lowers your insulin levels, which means that the next time you eat, your body will absorb nutrients more efficiently. And this is just a summative snapshot.   


The Evolution of Eating

I think it is very important at this point to make it clear that I am not a doctor, nor do I play one on the internet (to use the classic Tim Ferriss catch phrase). I simply love research and this article is only a reflection my understanding of the studies and resources I have used to learn about fasting for my own experimentation. Please, if this is something that interests you:

  • Do your own research as well. If you can stomach technical talk, the work of Dr. Valter Longo and Rhonda Patrick is the majority of what I look to. Otherwise, some more digestible resources would be the work of James Clear and Tim Ferriss, two rigorous and research beholden self-experimenters. Thankfully, Tim and James are also NYT best-selling authors—a trait not often shared with most scientific writers
  • Talk to your doctor. Though fasting is shown to have significant health benefits in many areas, everyone’s body is different. It is absolutely essential to remember that you have to figure out what is right for you in your own journey of health and wellbeing.


We are learning more and more every day about the nuances that govern our bodies’ operations, and we still have much farther to go. That, to me, is incredibly exciting. This is just a brief introduction to this concept, but it is the idea of the thing that holds meaning. The simple fact that we as a species are still learning how to eat is extraordinary. Something that should be so simple contains within itself a world of complexity.