Guide to health: Nutrition and physical activity outcomes of a group-randomized trial of an internet-based intervention in churches

Abstract
Background: Theory-based interventions accessible to large groups of people are needed to induce favorable shifts in health behaviors and body weight.Purpose: The aim was to assess nutrition; physical activity; and, secondarily, body weight in the tailored, social cognitive Guide to Health (GTH) Internet intervention delivered in churches.Methods: Participants (N=1,071; 33% male, 23% African American, 57% with body mass index ≥25, 60% sedentary, Mdn age=53 years) within 14 Baptist or United Methodist churches were randomized to the GTH intervention only (GTH-Only; 5 churches), with church-based supports (GTH-Plus; 5 churches), or to a waitlist (control; 4 churches). Verified pedometer step counts, measured body weight, fat, fiber, and fruit and vegetable (F&V) servings from food frequency and supermarket receipts were collected at pretest, posttest (7 months after pretest), and follow-up (16 months after pretest).Results: Participants in GTH-Only increased F&V at post (∼1.50 servings) compared to control (∼0.50 servings; p=.005) and at follow-up (∼1.20 vs. ∼0.50 servings; p=.038) and increased fiber at post (∼3.00 g) compared to control (∼1.5 g; p=.006) and follow-up (∼3.00 g vs. ∼2.00 g; p=.040). GTH-Plus participants compared to control increased steps at post (∼1,500 steps/day vs. ∼400 steps/day; p=.050) and follow-up (∼1,000 steps/day vs. ∼−50 steps/day; p=.010), increased F&V at post (∼1.5 servings; p=.007) and follow-up (∼1.3 servings; p=.014), increased fiber at post (∼3.00 g; p=.013), and follow-up (∼3.00; p=.050) and decreased weight at post (∼−0.30 kg vs. ∼+0.60 kg; p=.030).Conclusions: Compared to control, both GTH treatments improved nutrition at posttest, but church supports improved physical activity and nutrition at posttest and follow-up, suggesting environmental supports may improve Internet-based interventions.