The use of sugar and starch-like foods for energy (carbohydrate metabolism) changes when people sleep. However, it is still not known if differences in the amount of nighttime sleep have an effect on the carbohydrate metabolism of people who have a relative with type 2 diabetes (parent, sibling, or grandparent). This study is being done to test the hypothesis that the carbohydrate metabolism of people who have a history of type 2 diabetes in their family will be different after they have slept short hours for 10 days in comparison to when they have slept longer hours for 10 days.