The Biology of Fasting

Following on the conclusions I noted in Sensible Diets, I realized the mental state that many of our ancestors got into during a hunting or foraging phase is what, biologically, fasting is supposed to recreate. Once we get past the nasty little insulin spikes (which serve to drive us back to known food sources until they are gone), we start to burn stored fat and begin to move around in search of new food sources. We become more alert. We are searching for something.

I believe the mental state brought about under these conditions, the mental state that facilitates hunting, is in harmony with the reasons a believer fasts. Any mammalian omnivore will stay near the banana tree until all the fruit is eaten, but those that begin to hunt have put behind them the old and are looking for the new.
Obviously, this mental state alone isn't enough- that's why when one looks for biblical references to fasting one usually finds biblical references to prayer as well.

Unfortunately, many of us never get past the insulin spike stage, so we get tired, irritable, and sometimes people tell us the value of the fast is in the suffering. Some of us, sensing the complete inanity of trying to get closer to God by turning ourselves into angry jerks, just stop. A much smaller group, enjoying the seductive simplicity of the equation suffering=closer to God, seek more suffering. Biblically speaking, suffering is always for something. One lays down one's life, for instance, in the expectaction that one will save the lives of one's friends. We are not supposed to just go about laying down our lives willy-nilly. Similarly, there must be parameters to a fast that are understandable and, as long as we are limited to these fallible bodies we can expect to find an awful lot of those limits right within our bodies.

Anyway, if you are skeptical, let me point out that this hypothesis is extremely testable.