Motivation, Segmented Physical Activity, Sedentary Behavior, And Weight Status In Adolescents: A Path Analysis

Abstract

PURPOSE: The purpose of this study was to examine the relationships linking motivational variables with BMI percentile (BMI%) via segmented physical activity (PA) and sedentary behavior (SB) in adolescents using path analysis. METHODS: Secondary data analysis was performed using participants from the Family, Life, Activity, Sun, Health, and Eating (FLASHE) study. A non-probability panel balanced to the US population on sex, Census division, household income and size, and race/ethnicity were screened for eligibility. The final sample consisted of 1,643 adolescents (822 girls, 821 boys). Motivational variables consisted of PA enjoyment, self-efficacy, and peer social support. Mediator variables consisted of segmented weekly PA and SB assessed using the Youth Activity Profile (YAP). BMI% was the outcome. A recursive bootstrapped path analysis was conducted to examine the relationships between motivational variables, segmented PA and SB, and BMI% with indirect effects calculated via bootstrapped mediation analyses. RESULTS: The relationships between motivational variables and segmented PA and SB were stronger than relationships between segmented PA and SB and BMI%. Three mediated paths were observed: self-efficacy and BMI% using sedentary YAP as the mediator (IE = -0.38, 95%CI: -0.65, -0.18), enjoyment and BMI% using weekend YAP as the mediator (IE = -0.62, 95%CI: -1.14, -0.12) and social support and BMI% using weekend YAP as the mediator (IE = -0.53, 95%CI: -1.00, -0.07). CONCLUSIONS: The relationship between adolescent motivational variables and segmented PA and SB is relatively strong and specific motivational variables’ relationships with BMI% is mediated through segmented PA and SB. This is one of the few studies to examine these relationships using a large U.S. sample of adolescents, supporting strong external validity evidence to the U.S. adolescent population. It also adds to the knowledge base regarding the relative strength of the inter-relationships among the observed variables. The relationships among motivation, PA, and health outcomes are complex and this study provides some new information that can be used to promote PA and reduce SB in the adolescent population.