Abstract PO-188: The relationship of intervention attendance, changes in self-efficacy, social support, health behaviors, and weight loss outcomes among overweight Appalachian adults

Objectives: To determine whether self-efficacy and social support mediate the association between intervention attendance and changes in health behaviors; and to quantify the dose-response relationship between changes in health behaviors and weight loss outcomes. Methods: Data were from a group-randomized trial that compared a 1-year faith-based weight loss intervention to an active control group among overweight Appalachian adults in churches. Participants from the weight loss group who completed the 12-month assessment were included. Intervention attendance was defined as the percentage of sessions attended. Baseline and 12-month data on weight, self-efficacy for physical activity (SEPA), social support for eating healthy (SSEH), social support for physical activity (SSPA), exercise, and dietary intake were used. Mixed effect models were used to control for the random-effect of geographic regions. Results: Among the 243 included participants, most were female (76.2%), white (97.5%), and married or living with a partner (81.2%). After the 12-month intervention, participants lost 1.12±0.33kg weight, increased 0.44±0.13 servings/day of fruit and vegetable, reduced 321.55±41.99kcal/day of caloric intake, improved SSEH from family and friends, and increased SSPA from the church family (all P<0.05). Each 10% increase in intervention attendance was associated with higher odds of increased SSEH from family (OR=1.17, 95% CI=1.06-1.30) and friends (OR=1.16, 95% CI=1.04-1.28), and higher odds of increased SSPA from the church family (OR=1.27, 95% CI=1.12-1.44). SSPA from the church family mediated 96.7% of the association between intervention attendance and total exercise MET·min/week. Although intervention attendance was associated with increased walking MET·min/week, SEPA, SSPA from family/friends/church did not mediate the association. Additionally, with every 100 kcal decrease in caloric intake, weight and BMI decreased at 12-months (0.15±0.05kg, P=0.002; 0.058±0.017kg/m², P=0.001). After adjusting for exercise, each 100 kcal decrease in caloric intake was associated with a decrease in weight and at 12-months (0.17±0.05kg, P=0.001; 0.065±0.019kg/m², P=0.001). Conclusion: Social support from the church family plays an important role in increasing physical activity. There was a dose-response relationship between daily caloric intake and weight loss among Appalachian residents. Strategies to improve social support and reduce caloric intake are needed to improve the efficacy of weight loss through lifestyle modifications for this population. Citation Format: Xiaochen Zhang, Ryan D Baltic, Abigail Shoben, Electra D. Paskett. The relationship of intervention attendance, changes in self-efficacy, social support, health behaviors, and weight loss outcomes among overweight Appalachian adults [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-188.