Sleep quality as a moderator between self-control and the intention-behavior gap of diet and physical activity.

Meta-analyses and weight regulation treatment studies found inconsistent direct relationships between cognitive self-control and complicated behaviors such as healthy diet and engagement in physical activity. Variability in relationships may be due to challenging conditions such as sleep restriction the night before assessment, which has been shown to impact self-regulatory capacity the following day. In fact, varying levels of sleep quality complaints are independently associated with execution of health behaviors such as diet and physical activity. Although studies assess direct relationships between sleep, self-control and health behaviors, no study to date has examined how sleep quality complaints moderate the relationship between cognitive self-control and health behaviors while accounting for individual differences in intention. Barber and Munz (2011) found college students who self-reported consistent, good-quality sleep throughout a 5-day period experienced greater self-regulatory task strength (handgrip task) and lower perceived psychological strain compared to baselines measurements. These results indicate sleep complaints are associated with performance on a simple self-regulatory task, but findings may not apply to complicated self-control tasks such as weight regulating behaviors. The present study was designed to measure whether the interaction between objective measures of self-control (working memory or inhibition) and sleep quality complaints predict successful execution of diet and physical activity goals. Multiple hierarchical linear regression models were used to analyze the interaction effects of sleep quality complaints and self-control on health behavior. Results indicate sleep latency moderates the relationship between working memory and the intention-behavior gap of vegetable consumption, but not intention-behavior gaps of fruit consumption or engagement in physical activity. Findings can inform future interventions aimed at increasing control over weight gain among students during their transition from high school to college.