The Longitudinal Examination of Habitual Sleep Duration in Relation to Weight Gain Risk Behaviors and Body Composition Changes Among College Students: Project XXXXXXX.

Background: The purpose of the current study was to examine habitual sleep duration trajectories across the first two years of college and determine whether the trajectories were related to weight gain risk behaviors and increases in body mass index (BMI) and percent body fat. Methods: A sample of 115 students with a BMI between 18.5-29.9 were enrolled prior to beginning their first year of college. Data were collected at three time points across the first two years of college and data collection was conducted both in laboratory and remotely. Participants participated in a total of eight in-person sessions and three eight-day, at-home recording periods. There were objective measures of body fat composition (i.e., dual-energy X-ray absorptiometry), BMI, sleep (i.e., Phillips Respironics Actiwatch 2 Device), and physical activity (i.e., Actigraph wGT3x-BT accelerometer). Self-report measures of sleep quality (i.e., Pittsburgh Sleep Quality Index) and food and beverage intake (i.e., ASA-24) were also collected. Results: The findings suggest that there were no habitual sleep duration trajectories observed; therefore, none of outcome variables were examined in relation to trajectories. Follow-up mixed effects models suggest that as poor sleep quality worsened, BMI increased both within participants and across the sample. No other significant relationships were found between sleep duration and quality and the other outcome variables. Conclusions: The findings highlight subjective sleep quality as potential key component in relation to obesity-related changes. Sample characteristics may have also played a role in the limited findings between the sleep variables and the other obesity-risk outcome variables.