Researchers have known for a long time that a lack of sleep–or poor quality sleep–can lead to obesity, high blood glucose levels, and type 2 diabetes. But until now, they didn’t know why. A recent study published in the journal Diabetologia has shown them one possibility. It showed that not getting enough sleep can lead to high levels of free fatty acids in the blood, which stops insulin from working as well as it should. In turn, this leads to high blood glucose levels and, eventually, type 2 diabetes.

The researchers looked at 19 healthy men between the ages of 18 and 30. They let one group get eight hours of sleep each night for four nights. The other men were only allowed four hours of sleep each night. In the second group, blood levels of fatty acids spiked in the morning and stayed high for about five hours after they woke up. (In a healthy person, fatty acid levels are supposed to spike and then drop again during the night.) The group that got eight hours of sleep each night did not have this problem, which means their bodies had an easier time regulating their blood glucose levels. The researchers hope that by helping people get more sleep, they can stop the rise of obesity and diabetes in the U.S.

According to the Mayo Clinic, there are a few steps you can take each day to ensure that you get enough sleep:

• Keep your room cool, dark, and quiet.

• Don’t drink alcohol or eat too much just before to bedtime.

• Try to go to sleep and wake up at the same time each day.

• Avoid naps during the day.

• Get enough physical activity, but not too close to bedtime.

• Take time to relax before bed.