Date of Award
Master of Science
Melissa Hansen-Petrik, Kelley Strohacker
Background: Chronotype describes how well sleep patterns are synchronized with the overall circadian timing system (CTS). Those with a preference for Morningness have a CTS that is more optimally synchronized. A chronotype of Morningness versus Eveningness is related to more favorable dietary intake, physical activity and sleep patterns, and weight status. While chronotype is reflective of biological rhythms, as it suggests alignment with the light/dark cycle, the Social Rhythm Metric (SRM) is a measure of behavioral rhythms. The SRM assesses consistency of behavioral schedules, such as eating and physical activity, with higher scoresreflecting greater consistency. While research has found that a chronotype of Morningness versus Eveningness is related to better SRM, diet, physical activity, and anthropometric outcomes, it is unknown if SRM is related to these health outcomes. Thus, it was hypothesized that in young adults a greater SRM score would be related to higher diet quality, greater physical activity, greater sleep length and efficiency, and lower anthropometric measurements. Methods: This cross-sectional study assessed chronotype along with the independent variable of SRM and the dependent variables of diet quality, via food records, physical activity and sleep, via accelerometers, and anthropometrics. A linear hierarchical regression analyzed the relationship between SRM scores and the variables of diet, physical activity, sleep, and anthropometrics, while controlling for chronotype and gender. Results: Complete data were collected from 59 participants, aged 18 to 34 years (mean = 22.7 ± 4.2 yrs.). The majority of participants were female (83%), never married (87%), white (71%), and not Hispanic or Latino (97%). The regression for sleep efficiency was significant (R2 change = 0.106, p = 0.009). There were no significant relationships for SRM and the remaining variables of diet, physical activity, sleep, and anthropometrics. Conclusion: Participants with greater consistency in behavioral schedules were found to have greater sleep efficiency, suggesting better synchronization of the CTS. Future research is needed in larger, more generalizable samples to better understand the relationship between SRM and health outcomes.
Hawkins, Grace Marie, "Social Rhythms and Health Outcomes in Young Adults. " Master's Thesis, University of Tennessee, 2020.