McDonald’s wants you to lie awake at night. Why? Because the less sleep you get, the more you’ll want a Big Mac. That, according to researchers at the University of California at Berkeley, who studied the sleep and eating habits of 23 healthy young adults. A UC Berkeley news release reports that the researchers measured brain activity of sleep deprived participants as they viewed 80 food images, including fruits and vegetables, such as strawberries, apples and carrots, to high-calorie burgers, pizza and doughnuts, and rated their desire for each of the items. The researchers found that a lack of sleep correlated with greater desire for unhealthy snack and junk foods. Read more from UC Berkeley.