The Power of Fasting
One recent "puzzle piece" fit for me and many others has been to greatly reduce my “eating windows” and more consistently practice intermittent fasting. A powerfully positive health-promoting intervention is to just not eat for various periods, for example, 16 hours, 23 hours, or 35 hours, with occasional longer stretches (each person should consult with professionals before doing this, especially if already on a medication that might have to be adjusted).
While fasting traditions have been around and recognized as health promoting on many levels for at least thousands of years all around the world, no one is positioned to profit from fasting except the person actually doing it. There is no special food to order and no special medicine to consume and no complicated log book to fill out (just stop and start times if you like).
Already being fat-adapted and in ketosis makes fasting far easier, almost unnoticeable, except for the improved concentration and the freedom and flexibility from always being locked into having to have that very next meal or snack. While transitioning is required to get used to a ketogenic state, anywhere from days to weeks and beyond, once there, I have experienced consistent benefits from nutritional ketosis, fasting ketosis, and their interplay. And by the way, when eating, eat. This is an effort to better balance feast and famine and it should therefore certainly include the feasting parts to be successful. The modern problem is that there is too much consistent "feasting" (constant consumption) with woefully insufficient breaks from it. Fasting means intentionally adjusting this balance.
I think of fasting as intentionally replicating a "bad-hunting day" from the paleolithic past. Of course, no self-respecting paleo hunting group would have decided to have a bad-hunting day, but they would have had some nevertheless. To replicate that, moderns have to go out of their way to decide to do so. My most common practice nowadays is just to pick a day every few weeks, usually on a weekend, on which to not eat anything. This ends up creating about a 36–40 hour fast for me. I do allow water, teas, and some bone broth.
In case of a bad-hunting phase leading to hunger, one should expect our bodies to send the following message: get out there and hunt, and hunt more effectively than in the past few days. That means: more energy and enhanced concentration and attention should follow from fasting. It certainly does not mean getting cold and depressed in the cave, a sure path to non-survival.
The problem is that the modern approach to “calorie reducing,” while still eating the same regular, but smaller, meals, has a set of effects opposite to the positive affects of fasting, as Dr. Jason Fung argues in The Obesity Code (2016). With chronic low-cal dieting, metabolism sinks, energy and concentration fall, hunger is constant, and one feels colder.
But this is the opposite experience of actual fasting (especially after adaptation). However, it is just this “reducing” (eating marginally less regularly) as opposed to true fasting (not eating at all, or eating very very little, for defined periods), that is the one doomed constant in almost every failing “diet” plan out there. A central reason for this difference is now clearly understood from controlled trial and biochemical research: the two conditions have completely different impacts on the key phenomenon of insulin resistance.
This page has suggested the importance of not eating sometimes. Next, when we do eat, what should we eat to thrive?