In common weight-loss advice, "get more sleep," should figure just as prominently as "eat less" and "move more," two researchers in Canada argue.
The researchers pointed to a 2010 study in which participants were randomly assigned to sleep either 5.5 hours or 8.5 hours every night for 14 days. They all cut their daily calorie intake by 680 calories, and slept in a lab. Participants who slept for 5.5 hours lost 55 percent less body fat, and 60 percent more of their lean body mass than those who slept for longer.
In other words, the sleep-deprived people held onto their fat tissue, and instead lost muscle.