Observational StudyNighttime Synchrony of Your Nutrition and Circadian Health

Inclusion Criteria:

1. Age: 18-35 years old; equal numbers of men and women
2. Body Mass Index (BMI): 18.5-24.9 kg/m2
3. Sleep Habits: habitual self-reported average total sleep time (TST) 7-9 hours per night for prior 6 months

Exclusion Criteria:

1. Clinically diagnosed sleep disorder or apnea hypopnea index (AHI) ≥5
2. Evidence of significant organ system dysfunction or disease (e.g., heart disease, diabetes)
3. Fasting plasma glucose ≥100 mg/dL
4. Major psychiatric illness (e.g., major depressive disorder)
5. Cancer that has been in remission less than 5 years
6. History of shift-work in prior year
7. Weight change >5% of body weight over prior six months
8. Currently following a weight-loss program
9. Menopause
10. Pregnant/nursing
11. Greater than 5-day variation in menstrual cycle length month-to-month
12. Currently smoking
13. Alcohol intake >14 drinks/week or >3 drinks/day.
14. Use of prescription medications (except oral contraceptives) within one month prior to or during in-lab visits.
15. Consumption of illegal drugs or >500mg per day of caffeine.