Clinical Research Directory

Inclusion Criteria: * All racial and ethnic groups * Body mass index 20-34.9 kg/m2 * Average sleep duration ≥7 hour/night, assessed during 2-week screening period * Eat within 1 hour of awakening at least 5 days/week * Midpoint of sleep at 4 AM or earlier Exclusion Criteria: * \<10 nights of sleep \<7 hour during the 2-week screening period * Daytime napping * Current or past sleep disorder (Sleep Disorders Inventory); Insomnia Severity Index Score \>10 * Current or past psychiatric disorder, including eating disorders and seasonal affective disorder * Any psychological or psychiatric disorder deemed to interfere with study outcomes * Smoking (currently smoking any cigarettes or using tobacco products, e-cigarettes and vapes, or ex-smokers \<3 years) * Night and rotating shift work * Travel across time zones within 4 wk of the study * History of drug or alcohol abuse or excessive alcohol consumption (\>3 drinks/day for men or 2 for women) * Recent weight change (\>5% gain or loss of body weight over past 3 months) or active participation in diet or weight loss program in previous 3 months; any weight loss procedure * Pregnancy or \<1 year post-partum * Diagnosed sleep apnea or high-risk score on Berlin questionnaire (2 or more categories with positive score) * Depression (score \>13 on Beck Depression Inventory II) or taking anti-depressive medications * Restless leg syndrome and circadian rhythm disorders * Dementia or cognitive impairments * Taking psychoactive or hypnotic medications * Taking chronic analgesic or anti-inflammatory medications * Having had gastrointestinal surgery, including gastric bypass surgery * Restrained eating or abnormal scores on the Three Factor Eating Questionnaire * Contraindications for magnetic resonance imaging scanning * Hematocrit \<30% * Taking beta blockers, as this can interfere with melatonin secretion