A new study connects a lack of sleep to increased obesity and diabetes by showing how sleep deprivation can hurt people on a cellular level. A new study published in the Annals of Internal Medicine this week involved a very small sample size, but the subjects were placed on strict diets and limited to just four and a half hours of sleep a night. After just four nights, the researchers found that their fat cells had developed a decreased sensitivity to insulin, which regulates blood sugar and metabolism. If that insulin resistance persists, it can lead to weight gain, diabetes, and heart disease. Another recent study showed a similar insulin resistance in teenagers who don't sleep enough.

The study is still too limited to draw definitive conclusions, but the fact that subjects showed such dramatic changes after just four nights of sleep deprivation are shocking. The lead author of the study says, "This is the equivalent of metabolically aging someone 10 to 20 years just from four nights of partial sleep restriction." Considering that most Americans don't get the recommended seven to eight hours of sleep each night, that could be at least partial explanation for the steep rise in obesity in this country. It's also a good reason to go back to bed.

Photo by Ostill via Shutterstock