Going at least 12 hours without eating has pretty amazing weight-loss benefits, a new Salk Institute study has found.
Groups of mice on various diets (normal food or food high in sugar/fat) were either allowed to eat around the clock or forced to fast 12 hours a night.
Result: Mice that fasted at least 12 hours gained less weight overall than mice that were fed the same type and amount of food but had the run of the feed through all 24 hours. Even when the fasters got free “weekend passes” to gorge anytime, in the end they still put on fewer pounds (OK, grams) than the nonstop nibblers. And when non-fasting obese mice were put on the 12-hour fast, they dropped 5% of their body weight—though they were eating the same calories!
The researchers, who hope to conduct human trials soon, theorize that overnight fasting makes the body switch from burning food to burning fat.
Intermittent-fasting expert Mark Mattson, Ph.D., of Johns Hopkins U., even advises limiting food intake to an eight-hour window, to give your body a full 16 hours to act as a fat-burning furnace. Sure, a 9 a.m. breakfast and 5 p.m. dinner may not be an easy lifestyle to follow—but oh, those early bird specials!