A Good Night's Sleep: Future Antidote to the Obesity Epidemic?

It is well established that the prevalence of obesity has been increasing over recent decades, both in the United States and the rest of the developed world. Why is this happening? Body weight is physiologically regulated, and this regulation involves a complex physiologic system encoded by an array of specific genes (1). This system involves both central and peripheral components and interacts with aspects of the environment, such as availability and composition of the diet and the need for physical exercise, to influence body weight. Although genes play a critical role in weight determination, the increased prevalence in obesity of populations over a period of decades is induced by changes in the environment in which we live rather than changes in our genetic endowment. In thinking about the environmental variables that are probably responsible for the “obesity epidemic,” most of the attention has focused on the status and cost of the food supply, the composition of the food that we ingest, and our capacity for or avoidance of physical exertion. Is it possible that we have missed other environmental variables that have a capacity to modify appetite and energy balance? In this issue, Spiegel and colleagues (2) present experimental results suggesting that increasing sleep deficits (or debts), perhaps a result of our hectic lifestyles, bring about physiologic changes in the hormonal signals that promote hunger and, perhaps thereby, obesity.