DIJON, France—Men who do not receive a good night’s sleep may be prone to obesity, according to a new study from the European Centre for Taste Sciences. The study, published in the American Journal of Clinical Nutrition, found study participants consumed 22 percent more calories with an average calorie increase of about 560 after the short night of sleep. The researchers suggest people may eat more after a short night of sleep because mammals have evolved to store up calories in the summer, when nights are short and food is plentiful.
Twelve men completed a randomized two-condition crossover study. During the first night of each 48-hour session, subjects had either eight hours (from midnight to 8:00 a.m.) or four hours (from 2:00 a.m. to 6:00 a.m.) of sleep. All foods consumed subsequently (jam on buttered toast for breakfast, buffet for lunch, and a free menu for dinner) were eaten ad libitum. Physical activity was recorded by an actimeter. Feelings of hunger, perceived pleasantness of the foods, desire to eat some foods, and sensation of sleepiness were also evaluated.
In comparison with the eight-hour sleep session, subjects consumed 559 ± 617 kcal (i.e., 22 percent) more energy on the day after sleep restriction (P<0.01), and preprandial hunger was higher before breakfast (P<0.001) and dinner (P<0.05). No change in the perceived pleasantness of the foods or in the desire to eat the foods was observed. Physical activity from 12:15 p.m. to 8:15 p.m. was higher after sleep restriction than after eight hours of sleep (P<0.01), even though the sensation of sleepiness was more marked (P<0.01).