Sleep deprivation alters hormones and increases appetite, according to the results of a randomized study published in the Dec. 7, 2004 issue of the Annals of Internal Medicine. "Total sleep deprivation in rodents and in humans has been associated with hyperphagia," write Karine Spiegel, PhD, from the University of Chicago in Illinois, and colleagues. "Over the past 40 years, self-reported sleep duration in the United States has decreased by almost two hours."

In this two-period, two-condition crossover clinical study, subjects were randomized to two days of sleep restriction (four hours per night) and two days of sleep extension under controlled conditions of energy intake and physical activity. During sleep restriction, there was an 18% decrease in the anorexigenic hormone leptin (P = .04), 28% increase in the orexigenic factor ghrelin (P < 0.40), 24% increase in hunger (P < .01), and 23% increase in appetite (P = .01), especially for energy-dense foods with high carbohydrate content (increase, 33% to 45%; P = .02). In animal models, sleep deprivation has been shown to lead to marked hyperphagia (eating more) as well.

In the past 40 years, sleep loss has increased dramatically. Self-reported sleep duration in the U.S. decreased by one to two hours for the second half of the 20th century. The proportion of young adults sleeping 8 to 8.9 hours per night has decreased from 41% in 1960 to 23.5% in 2001 to 2002. During this time, the incidence of obesity has nearly doubled. It is very likely that sleep curtailment in humans may be a risk factor for obesity.

Bottom line. You can't fool mother nature. We don't just cause premature aging from lack of sleep, it also encourages overeating. We consistently observe that when we don't meet our body's needs for sleep, exercise, highly nutritious food, clean air and water, we pay a price-disease. Health care should not merely be "drug care and drug research" it should involve improving the quality of air, water and food supply and educating the public about the key issues to protect their health.