The mediating role of social support in behavioral changes and weight loss outcomes among overweight Appalachian adults

Social support plays a key role in behavioral changes, especially in Appalachian populations. We examined the mediating effect of social support in behavioral changes and corresponding weight loss outcomes among Appalachian adults. Data were from a group-randomized trial that compared a 12-month faith-based weight loss intervention to an active control group among overweight Appalachian adults in churches. Participants from the weight loss intervention who completed the 12-month assessment were the focus of this analysis. Baseline and 12-month data on weight, social support for eating habits (SSEH) and physical activity (SSPA) from family, friends, and church family, physical activity, and dietary intake were collected. Logistic and linear regression models evaluated mediating effects of SSEH and SSPA on the association between intervention attendance and behavioral changes and corresponding weight loss outcomes. Most participants (n = 243) were female (76.2%), white (97.5%), and married or living with a partner (81.2%). After the 12-month intervention, participants lost weight (1.1 +/- 0.3 kg), increased fruit and vegetable intake (0.4 +/- 0.1servings/day), reduced caloric intake (322.9 +/- 42.2 kcal/day), improved SSEH from family, and increased SSPA from the church family (all P < 0.05). Increased SSEH from family mediated 62% of the association between intervention attendance and fruit and vegetable servings per day. Each 100 kcal decrease in caloric intake was associated with decreased weight and BMI at 12-months (0.2 +/- 0.1 kg, P = 0.003; 0.1 +/- 0.02 kg/m2, P = 0.002). Our study demonstrated the mediation effect of social support for healthy eating on the association between intervention attendance and fruit and vegetable intake, which underscored the critical role of social support and calorie intake among Appalachian populations in losing weight. The study was preregistered at clinicaltrials.gov (#NCT02121691).