Impact of Sleep Extension in Adolescents

Many teenagers do not get enough sleep. Obesity and diabetes are increasing in teenagers as well. This study plans to learn more about sleep and insulin resistance (insulin not working) in teenagers, and how these things may be related depending on sleep. This is important to know so that the investigators understand how sleep may play a role in health conditions like extra weight gain (increased food intake and less physical activity) and diabetes. To answer this question, the investigators plan to enroll teenagers who get \<7 hours of sleep on school nights and measure changes in insulin sensitivity and dietary intake after a week of typical sleep (sleeping on their normal school schedule) and a week of longer sleep (spending 1+ hour longer in bed each night).