Chapter 6. Food Timing: When to Eat, When to Fast

Fasting is a scary thought to some people. Food is deemed important for all kinds of reasons other than raw hunger. What’s that line I keep seeing painted on restaurant walls and on websites: food is love? Fasting means no food, for hours on end (although at least half of the hours are spent asleep).

In the 2002 remake of the movie Swept Away, Madonna’s character talks about the virtues of fasting, and that line is supposed to make you hate fasting, because she’s promoting it, and her character is a snarling, narcissistic plutocrat. But fasting is virtuous, from a symbolic, religious, and ethical standpoint, and there’s even good scientific evidence that a modified form of this practice, called intermittent fasting, is quite healthy.


People fast for lots of reasons: in solidarity with groups that are suffering persecution, for instance, such as the thousands of displaced people in the Darfur region of Africa (see As for religion, in Judaism, for example, the Yom Kippur fast lasts 25 hours. During the Muslim Ramadan tradition, the fast takes place from dawn to dusk each day.

Here comes that human-evolution angle again—we seem to be naturally evolved for fasting. Humans and mammals in general respond metabolically very well to it (see the sidebars covering the science behind fasting). This adaptation may have evolved from our ancestors’ activity patterns. They had to constantly physically seek food, and must ...

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