The goal of this study is to determine how sleep and circadian rhythm alignment contribute to neurobehavioral and behavioral mechanisms of cardiometabolic risk. The investigators propose that circadian misalignment, which is more common among individuals with late sleep timing, leads to increased consumption of energy dense/prepared foods and to decreased insulin sensitivity. Short sleep duration and neurobehavioral measures (i.e. delay discounting) may moderate these associations, thus exacerbating cardiometabolic risk factors. There is evidence for a direct biological link between circadian misalignment and insulin resistance, and for a relationship that is mediated through changes in eating behaviors. Insulin resistance and increased caloric intake over time lead to increased BMI and body fat.~In this study, the investigators will conduct cross-sectional and longitudinal analyses to determine biological and behavioral mechanisms that link circadian alignment and sleep duration to changes in cardiometabolic risk over 1 year. This study will identify individual differences that predict risk for cardiometabolic disorders and suggest potential for sleep, circadian and neurobehavioral interventions to reduce cardiometabolic risk.
This study design will test biological and behavioral mechanisms in the cross-sectional analyses and determine the prospective effects of circadian alignment and sleep on changes in cardiometabolic risk factors.