Have the benefits of intermittent fasting been overhyped?

What's more, the more intense forms of intermittent fasting – such as eating every other day – may make a person less metabolically healthy by stripping away lean body mass.

This popular and wide-ranging diet, which involves either fasting on certain days of the week, or restricting food intake to certain hours of the day, has acquired a reputation for making weight loss easier than standard calorie reduction.

The need for knowledge Mattson thinks clinical trials of intermittent fasting should go further still, to include data not just on compliance, food composition, and calories, but also physical activity and sleep, activities that are also "precisely controlled for in animal studies.