Need another reason to hit the snooze button? Your fat cells need sleep, too!

The more shut-eye you catch at night, the easier your fat cells can prevent weight gain. In a new study published in Annals of Internal Medicine, researchers at the University of Chicago directly linked sleep loss to a decline in the cells’ ability to react to the hormone insulin.

In the study, seven people slept for 8.5 hours four nights in a row. Four weeks later, researchers repeated the process, but shortened each night’s sleep to a mere 4.5 hours. After less sleep, participants’ whole-body insulin sensitivity was down by an average of 16 percent.

What that means: In the short term, a decrease of fat cells’ insulin sensitivity can lessen the production of the hormone leptin, which goes to the brain and could both make you hungrier and heavier, says study author Matthew Brady, Ph.D., associate professor of medicine at Chicago. Even worse: Over the long term, continually low insulin sensitivity could lead to total-body resistance to insulin and the development of type 2 diabetes.

Brady says the fix could be as simple as grabbing the right amount of sleep each night, adding that it could be just as important as a balanced diet and exercise. “Just as you can become mentally groggy when you don’t get enough sleep, your fat cells can become metabolically groggy without enough sleep.” His recommendation: Catch at least seven hours each night.

Sound easier said than done? Discover How to Sleep Right, Tonight.