Lack of Sleep Causes Weight Gain

People who are sleep deprived for just one workweek tend to overeat and gain weight, according to a new study.

In a controlled lab test, 16 healthy adults were limited to just five hours of sleep over the course of five days—participants gained, on average, nearly 2 pounds and tended to eat meals later than expected. Surprisingly, participants burned more calories while sleep deprived, but ate more to make up for that fact.

"Sleep loss itself leads people to expend more energy because the body needs more to keep it awake," says Kenneth Wright, lead author of the report and director of the University of Colorado Sleep and Chronobiology Laboratory. "People eat more in response to these needs, but they eat more than they really need to, which leads to weight gain."