Lose Sleep, Gain Weight: Another Piece of the Obesity Puzzle

It's 11 P.M., and you sit in front of a glowing computer screen, writing e-mails and eating a sandwich. You'll work until after midnight, when you'll fall asleep in front of the light and blare of a TV before rising again at 6 A.M. What's wrong with this picture? Because of modern conveniences and pressures, many of us keep our bodies exposed to light, food, and activity at times when our organs and cells expect dark, quiet, and sleep.

In epidemiologic studies, shorter sleep has been correlated with incidence of obesity, hypertension, and other metabolic disorders. Experimental sleep studies find a similar connection. Increasingly, studies of the possible mechanisms behind these associations suggest that lack of sleep is part of a bigger problem with the 24/7 lifestyle many people today lead. Increasingly, scientists are finding that many physiologic activities related to metabolism don't happen continuously but oscillate on a regular schedule. Studies in mice as well as humans suggest that when our internal clock is disrupted, it may throw off many bodily functions, especially metabolism...