It has long been known that when you skimp on sleep, you’re far more likely to overeat, make poor food choices and gain weight. But why? Researchers from the University of Chicago Medical Center have figured it. The short answer: Too little sleep gives you the munchies. The long answer: Sleep loss amplifies and extends blood levels of a chemical signal that enhances the joy of eating, particularly the guilty pleasures gained from sweet or salty, high-fat snack foods. Fourteen sleep-deprived participants in this study, all of whom were young, healthy volunteers, were unable to resist cookies, candy and chips — even though they had consumed a meal that supplied 90 percent of their daily caloric needs two hours before. The effects of sleep loss on appetite were most powerful in the late afternoon and early evening, times when snacking has been linked to weight gain. During that period, sleep-restricted study subjects reported higher scores for hunger and a stronger desire to eat. When given access to snacks, they ate nearly twice as much fat as when they had slept for eight hours. The takeaway: When you get less than five hours of sleep, it will likely result in binge-eating the next day to the tune of an extra 300 calories.