Impact of Chronic Circadian Disruption vs. Chronic Sleep Restriction on Metabolism

Following a baseline of adequate time in bed, study participants will spend 3 weeks on a daily jet-lag schedule (where each day is longer than 24 hours).

Following a baseline of adequate time in bed, study participants will have a shortened opportunity for sleep during each 24-hour day (for three weeks).

Following a baseline of adequate time in bed, study participants will continue to have adequate time in bed and opportunity for sleep during each 24-hour day, for 3 weeks.