Thoughts on Fasting

I've written before about intermittent fasting and its benefits.  I think it's an essential piece to the overall puzzle, but it doesn't seem like the general thinking on the subject is complete.

For example, you can perform intermittent fasting by creating a compressed eating window.  If you normally take in 3,000 calories a day spread over six meals, you can instead compress that into say two big meals during a shortened time frame.  This may be beneficial and lead to improved health outcomes, but it seems somewhat artificial to me.  It doesn't tie fasting to any larger, overall eating pattern.

The real question is: why would a hunter-gatherer engage in intermittent fasting, that is, not eat for a period of time?  I can only come up with two main reasons:

1. They aren't hungry.
2. There is no food left.

And both of these are tied to the overall feeding or hunting cycle.  If they aren't hungry, it's probably because they've just had a period of good eating.  And if there's no food left, then they are most likely getting ready to look for new food, or are already in the process of searching for new food.

I've been researching the feeding cycles of animals, and here's a good paper on the subject.  Here's the first sentence from the abstract:

"Food intakes of wild animals may not match their requirements for nutrients and energy but may vary between periods of nutritional excess (hyperphagia) and nutritional deficit (hypophagia) at timescales that vary from days to months."

One part of the paper also addressed how feeding cycles relate to meals.  Here's the quote:

"Excess intakes are associated with more frequent or larger meals that infer a positive relationship between daily excess and maximum digesta fill."

So it appears that meal frequency and size is dictated by the feeding cycle: when there is excess, there are more frequent or larger meals.  On the other end of the spectrum, when there is a deficit there are fewer or smaller meals.  Intermittent fasting represents the far end of this spectrum, with no food and zero number of meals.