Today, I burned through Brad Pilon’s Eat Stop Eat, another book from the suggested reading list at Leangains.
This one was focused on Intermittent Fasting. The reading was short and sweet, but did not leave me completely convinced. He did add footnote citations, so I may look through those. The basic principle is that brief fasts drop insulin and raise glucagon and growth hormone, leading to fat loss.
Assuming that the science is solid, I’m not sure how I would implement it. There seem to be a lot of variations on IF. The author recommends 24-hour fasts once or twice a week. Leangains recommends a 16-hour (14 for women) fast every day. Fast-5 is another popular IF plan that recommends a 19-hour fast every day.
As for the rules — during the non-fasting times, you eat as normal. No extra calories in preparation for a fast or as reward after a fast. During the fasting times, only non-caloric drinks and sugar-free gum are allowed. From a strict calorie-restriction perspective, I can see how this plan would work. And it would be relatively easy to do long-term since there are no types of food restricted, but it seems to fall back to counting calories.