Effect of Sleep Extension on Ceramides in People With Overweight and Obesity

Inclusion Criteria: 1. Age: 18-45 years old; equal numbers of men and women 2. Body mass index (BMI): 27.5-34.9 kg/m2 3. Sleep Habits: habitual self-reported average total sleep time (TST) \<6.5 hours per night for prior 6 months Exclusion Criteria: 1. Clinically diagnosed sleep disorder or major psychiatric illness 2. Evidence of significant organ dysfunction or disease (e.g., heart disease, kidney disease) 3. Clinically diagnosed diabetes or fasting plasma glucose ≥126 mg/dL or HbA1c ≥6.5% 4. Use of prescription drugs or substances known to influence sleep or glucose metabolism, or anticoagulant medications. 5. Cancer that has been in remission less than 5 years 6. Pregnant/nursing, experiencing menopause or post-menopausal 7. Shift-work: current or history of within last year 8. Weight change: \>10% of body weight over prior six months 9. Current enrollment in weight loss or physical activity program like the Diabetes Prevention Program 10. Currently smoking 11. Alcohol intake\>14 drinks per week or \>3 drinks per day