Additional Study Information: The overall goal of this project is to assess the role of rest-activity patterns on glucose control, body composition, and well-being. We are currently looking for non-smoking men and women, age 25 years or older and with pre-diabetes (HbA1c 5.7-6.4%) to participate in this study. You must regularly sleep at least 6 hours/night and have variable sleep schedule (meaning going to bed and waking at different hours throughout the week). In addition, you must be willing to come to Columbia University Irving Medical Center for testing procedures. The screening process will take approximately 2 weeks and the study will last an additional 16 weeks. Testing will occur at the onset of the study and after 12 weeks. A follow-up visit at week 16 will also be scheduled. Compensation up to $500 will be provided.