Sleep Yourself Thinner?
If you're trying to lose weight, here's something you might add to your diet: 20 minutes of extra sleep each night. In a study reported in a recent issue of Archives of Internal Medicine, researchers compared body mass index (BMI) to sleep habits in about 1,000 subjects. After taking medical problems and sleep disorders into account, the researchers found that overweight and obese subjects slept less than those with a normal BMI. So what's going on in the body that might cause sleep time to affect weight? The most likely suspects are a couple of hormones called ghrelin and leptin. Rising leptin levels trigger a feeling of being "full." Rising ghrelin levels trigger feelings of hunger. Previous research has shown that among people who average only five hours of sleep each night, ghrelin tends to go up while leptin goes down. The opposite is generally true for people who average eight hours per night. The good news is that it may not take several hours of additional sleep for overweight people to bring their ghrelin and leptin levels in line. In this most recent study, the results suggest that many overweight people may experience benefits by adding just an additional 20 minutes of sleep each night. These results confirm a study reported last year that demonstrated how obesity risk may increase by as much as 50 percent among subjects who average five hours of sleep each night. Among subjects who averaged only six hours per night, obesity risk was increased by about 25 percent.