In brief

One more reason to get enough sleep

Most of us are familiar with the short-term costs of sleep deprivation: reduced alertness, daytime sleepiness, irritability, and trouble concentrating. Long-term sleep loss can have more serious health effects, including depression, hypertension, health problems, and stroke. Now some research is suggesting that insufficient sleep also contributes to obesity. Although the mechanism isn't entirely clear, the evidence implicates hormones that control appetite. If these findings are corroborated, getting enough sleep could emerge as a valuable addition to exercise and diet in achieving and maintaining a healthy weight.

Less sleep, higher body mass index

Several studies have examined the relationship between sleep and body weight. In one, researchers at Eastern Virginia Medical Center recruited 924 women and men, ages 18–91, from local medical practices and interviewed them about sleep habits, health problems, and sleep disorders. Weight and height measurements were taken and subjects were classified by body mass index, or BMI (see box below).