You know the feeling: It’s been a long day and now the clock is inching towards midnight—but you’re almost done watching a salacious season of reality TV. Should you watch just one more episode, or hit the sack? If you’re looking to shed some pounds, The Real Housewives will have to wait. A new study published in the Proceedings of the National Academy of Sciences found (surprise, surprise) that sleeping less has some pretty undesirable effects on the body. And while researchers already knew of a link between less sleep and weight gain, this study helps explain why the phenomenon occurs. Researchers at the University of Colorado at Boulder enlisted 16 young adults for a comprehensive sleep study. During the week leading up to the experiments, participants quit all caffeine and obtained adequate sleep. Then, for two weeks, they lived in the university’s hospital and were split into two groups: For five days, one group enjoyed a luxurious nine hours of sleep a night, while those in the other group got a scant (and more realistic) five hours daily. Then, they switched. Both groups received large meals and had unlimited access to yummy food. The results were clear: Sleeping five hours a night, combined with consistent access to food, caused participants to gain an average of two pounds. Interestingly, the people who slept less actually expended 5% more energy—the calories used up during a typical half-hour water aerobics workout—but they also consumed plenty more calories. “They were actually waking up at a time when their internal clock told them they should be sleeping still,” says Kenneth Wright Jr., PhD, an associate professor in the department of integrative physiology at the University of Colorado at Boulder. As a result, participants ate smaller morning meals—and then went overboard on late-night snacks. “They chose things that had a higher carbohydrates content: the cereal bars, the pretzels, the cookies, the potato chips,” Wright says. In fact, the group consumed more calories during post-dinner snacks than they did during any single meal. But there’s good news, too. When the groups switched, so did the numbers on the scale. Those who were allowed to catch up on sleep consumed fewer carbs and shed weight. “The result suggests that sleep itself may be part of a multi-component program where we can help people maintain weight or lose weight,” Wright says. (Curious about what else a sleep-deprived night does to your waistline? Check out 5 Ways Sleeping Less Makes You Gain Weight.) Questions? Comments? Contact Prevention’s News Team.
