Think less than five hours of sleep is enough? Think again. Lack of sleep might increase your chances of developing diabetes, according to a study by University of Chicago researchers, as reported by MedicineNet.

For the study, researchers evaluated five men and six women volunteers (averaging 40 years old). The slightly overweight participants exercised infrequently and slept a little less than eight hours daily, but were otherwise healthy.

Scientists confined the participants in a laboratory for two 14-day periods and checked their sleep, diet and blood chemistry. In addition, researchers prohibited exercise and provided them with junk food.

During one of the 14-day cycles, scientists allowed the volunteers to sleep 8.5 hours a day. For the other period, researchers permitted the participants only 5.5 hours of sleep each day.

The result? Study volunteers’ decreased sleeping time registered higher blood sugar levels on a glucose-tolerance test. In addition, they experienced a loss in sensitivity to insulin—a hormone that lowers blood sugar. Plus, all participants gained four pounds (regardless of number of hours slept).

“When the unhealthy aspects of the Westernized lifestyle are combined with reduced sleep duration, this might contribute to the increased risk of many overweight and sedentary individuals developing diabetes,” said lead researcher Plamen Penev, MD, PhD.

Learn how Angie Stone manages diabetes here.