This from a Doctor writing in the 'DAILY MAIL'. "Sleep helps your heart stay healthier and guard against blood pressure. More sleep helps your metabolism burn more calories. People who don't sleep enough have been found to have higher levels of glucose and cortisol in their blood and take 40% longer to regulate blood sugar levels. Good sleep can help guard against type II diabetes. You are less likely to get a paunch in middle age if you get more sleep because a lack of sleep drives down the production growth hormone. Growth hormone helps control the bodies proportion of fat and muscle".