Experimental studies with adolescents and adults suggest that inadequate sleep duration and poor sleep quality are associated with insulin resistance, glucose intolerance, increased ghrelin and increased markers of inflammation.14-20 However, no previous study has successfully examined the effects of a longer-term sleep intervention on factors related to obesity and type 2 diabetes. We propose that short sleep and poor sleep quality may lead to obesity and type 2 diabetes through 2 mechanisms: 1) increased ghrelin, which can lead to increased food intake, decreased energy expenditure and impaired glycemic control,18 and 2) decreased insulin sensitivity, which also increases insulin.16-20 These changes in energy balance and metabolism could lead to weight gain over time and increase adolescents' risk for type 2 diabetes.