Date of Award


Document Type

Open Access Dissertation




Clinical-Community Psychology

First Advisor

Dawn K. Wilson


This study examined the effects of a family-based intervention for improving moderate-to-vigorous physical activity (MVPA), sedentary behavior (SB), and fruit and vegetable (F&V) intake in African American adolescents. The intervention (Project SHINE: Supporting Health Interactively through Nutrition and Exercise) integrated Social Cognitive (SCT), Self Determination (SDT), and Family Systems Theories (FST) to improve healthy physical activity and dietary behaviors. Behavioral strategies from SCT (i.e., self-monitoring, goal-setting, self-regulatory skill-building), elements involved in facilitating intrinsic motivation for health behavior change from SDT (i.e., autonomy, competence, belongingness), and positive parenting practices from FST for integrating parent and peer systems (e.g., parental monitoring, parent-adolescent communication, parental management of peers) were combined to promote the development of a positive social environment supportive of improvements in adolescent MVPA, SB, and F&V intake. A total of 89 adolescents (12.5±1.4 yrs; 61% girls; 48% obese) and their caregivers (41.5±8.5 yrs; 92% females; 74% obese) were randomized to either the 6-week parenting intervention or general health program. Process evaluation measures were developed to assess intervention social climate and behavioral skills implementation. Data were collected at baseline and post-intervention and included demographics, anthropometrics (height, weight), 7-day acclerometry estimates of MVPA, self-reported SB (e.g., screen time, sitting, inactive hobbies), and psychosocial scales. Missing data were handled using multiple imputation (m=20), and multilevel regression models predicting post-intervention outcomes accounted for individuals nested within 10 groups. Models examined between-group differences in behavioral (i.e., MVPA, SB, F&V intake) and psychosocial outcomes (e.g., parent-adolescent communication, parental monitoring, parental management of peers) as well as whether changes in psychosocial scales were predictive of changes in behavioral outcomes. Process evaluation data indicated the intervention was implemented with adequate dose and fidelity and modest reach. There was a significant intervention effect on adolescent SB (B = -28.76, SE = 9.65, t = 2.98, p < .01), such that adolescents in the intervention condition reported ~28 less weekly hours of SB than did those in the comparison condition. No effects were found for adolescent MVPA or F&V intake. With regard to psychosocial outcomes, there was a significant intervention effect on parent-reported health communication (B = 0.52, SE = 0.15, t = 3.47, p < .01) and parent support for diet (B = 0.49, SE = 0.22, t = 2.19, p < .05) as well as trends for adolescent-reported health communication (B = 0.33, SE = 0.18, t = 1.83, p < .10) and parent support for physical activity at post intervention (B = 0.42, SE = 0.24, t = 1.75, p < .10). None of the other psychosocial variables were significantly different between groups at post intervention and changes in psychosocial variables did not predict changes in adolescent SB. Secondary analyses examining parent MVPA and F&V intake resulted in a significant effect of the intervention on parent MVPA (B = 9.43, SE = 4.21, p < .05), such that parents in the intervention condition engaged in ~8 more minutes per day of MVPA than did those in the comparison condition. Overall, findings suggest that an intervention designed to promote positive parenting practices, including communication around health, and behavioral skills may facilitate improvements in adolescent SB and parent MVPA.