The panel looked at studies that reported connections between the amount of sleep that people said they got and their health over long periods. The panel also took into consideration studies that monitored people in sleep labs that controlled how much sleep they got.
For example, Gangwisch and his colleagues have reported a connection between getting less than seven hours of sleep a night and high body mass index. Separate studies in sleep labs suggest how inadequate sleep could lead to obesity: it drives up the levels of appetite-inducing hormones.
The weight gain that might be caused by inadequate shut-eye could, in turn, increase the risk of heart attack and stroke, Gangwisch said. In addition, sleep deficits seem to increase blood pressure as several studies have found, which could be bad for heart health.