Even modest sleep loss may quietly lead to weight gain and raise the risk of chronic disease over time. “People tend to gain weight over the course of their adulthood, and obesity is a major risk factor for heart disease. But focusing on eating a healthier diet and getting more physical activity to offset weight gain is simplistic and can be difficult to maintain.” Those experiments have shown that severe sleep deprivation can alter appetite and encourage overeating, potentially contributing to weight gain over time. Sleep Loss May Affect Metabolic and Heart HealthThe researchers are still working to determine exactly why moderate sleep restriction contributes to weight gain.