Evidence suggests that there is a relationship between short sleep duration and obesity so the current study assessed energy balance during periods of short and habitual sleep. Fifteen men and 15 women aged 30–49 years with a body mass index of 22–26 kg/m2 who regularly slept 7–9 hours/night participated in this crossover study. Participants were studied under short (4 hour/night) and habitual (9 hour/night) sleep conditions, in random order, for five nights each. Food intake was measured on day five, and energy expenditure was measured with the doubly labeled water method over each period. Participants consumed more energy on day five during short sleep than during habitual sleep (P = 0.023) and this effect was mostly due to increased consumption of fat (P = 0.01), notably saturated fat (P = 0.038). Resting metabolic rate and total energy expenditure did not differ significantly between sleep phases. These data show that a reduction in sleep increases energy and fat intakes, which may explain the associations observed between sleep and obesity. If sustained and not compensated by increased energy expenditure, the dietary intakes of individuals undergoing short sleep predispose to obesity. Am J Clin Nutr. 2011 Aug;94(2):410-6. PMID: 21715510.
