One study found that after two weeks of minor calorie
restriction (10 percent
less than their daily energy expenditure), subjects who were getting 5.5 hours in bed a night lost just 0.6 kilogram of fat but 2.4 kilograms of other
tissue, such as muscle; subjects who got 8.5 hours slumber each night lost 1.4 kilograms of fat and 1.5 kilograms of other
tissue.