Eight hours is supposed to be the sleep magic number. But researchers say there really is no magic number – that your body knows when it has enough sleep. At the Centers for Disease Control and Prevention, Dr. Daniel Chapman: “It’s actually quite serious. Drowsy driving was implicated in about 16 percent of fatal crashes and about 13 percent of crashes resulting in hospitalization.” (10 seconds) Chapman says sleep is as important to health as eating right and getting enough physical activity. And research has been finding that lack of sleep – like poor diet and lack of physical activity – has been associated with weight gain and diabetes. Chapman also notes insufficient sleep’s special risks, like falling asleep at the wheel.