The BBC on intermittent fasting, from the Horizon series: "Scientists are uncovering evidence that short periods of fasting, if properly controlled, could achieve a number of health benefits. ... Calorie restriction, eating well but not much, is one of the few things that has been shown to extend life expectancy, at least in animals. We've known since the 1930s that mice put on a low-calorie, nutrient-rich diet live far longer. There is mounting evidence that the same is true in monkeys. ... One area of current research into diet is Alternate Day fasting (ADF), involving eating what you want one day, then a very restricted diet (fewer than 600 calories) the next, and most surprisingly, it does not seem to matter that much what you eat on non-fast days. [Researchers] carried out an eight-week trial comparing two groups of overweight patients on ADF. ... If you were sticking to your fast days, then in terms of cardiovascular disease risk, it didn't seem to matter if you were eating a high-fat or low-fat diet on your feed (non-fast) days."