Nighttime Synchrony of Your Nutrition and Circadian Health

Sleep is an important factor for overall health. This study will see how different light exposure patterns and food intake impact a person's metabolism (how the body breaks down food) when sleeping is reduced. Participants will attend 6 to 8 in-person visits to the study clinic, including three overnight stays. People will complete surveys and medical tests. The study will last about 4 to 6 months.

This study is a randomized in-lab, cross-over trial. Each participant will complete all three arms in either condition order #1 (A-B-C) or order #2 (A-C-B). Each arm will consist of 5 nights of experimental sleep restriction followed by a constant routine protocol for assessment of 24-h rhythms. Sleep restriction in the three arms will occur under the following conditions: (A-control condition) Sleep Restriction with Central and Peripheral Alignment; (B) Sleep Restriction with Central Clock Misalignment; and (C) Sleep Restriction with Peripheral Misalignment. Prior to enrollment participants will complete a comprehensive medical history and clinical overnight sleep disorders screening. Baseline consists of a \~2-week ambulatory real-world monitoring segment that will occur immediately prior to each in-lab sleep restriction condition. Following the 5 days of sleep restriction in each arm, participants will complete an intravenous glucose tolerance test to analyze insulin sensitivity, prior to completing the constant routine.