Impact of Sleep Restriction in Women

Inclusion Criteria: * Age 20-75 years old * All racial/ethnic groups * Body mass index 18.5-34.9 kg/m2 * Sleep 7-9 h in bed/night with no daytime nap * Normal scores on: Pittsburgh Quality of Sleep Questionnaire Epworth Sleepiness Scale, Berlin Questionnaire, Sleep Disorders Inventory Questionnaire, Beck Depression Inventory, Composite Scale of Morningness/Eveningness, Three Factor Eating Questionnaire Exclusion Criteria: * Smokers (any cigarettes or ex-smoker \<3 years) * Neurological, medical or psychiatric disorder * Diabetics * Regular use of any medication or supplement * Eating and/or sleep disorders * Contraindications for MRI scanning * Travel across time zones within 4 wk * History of drug and alcohol abuse * Shift worker (or rotating shift worker) * Caffeine intake \>300 mg/d * Oral contraceptive use or hormone replacement therapy * Heavy equipment operators * Commercial long-distance drivers.