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 > or = 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 (approximately 1.50 servings) compared to control (approximately 0.50 servings; p = .005) and at follow-up (approximately 1.20 vs. approximately 0.50 servings; p m = .038) and increased fiber at post (approximately 3.00 g) compared to control (approximately 1.5 g; p = .006) and follow-up (approximately 3.00 g vs. approximately 2.00 g; p = .040). GTH-Plus participants compared to control increased steps at post (approximately 1,500 steps/day vs. approximately 400 steps/day; p = .050) and follow-up (approximately 1,000 steps/day vs. approximately - 50 steps/day; p = .010), increased F&V at post (approximately 1.5 servings; p = .007) and follow-up (approximately 1.3 servings; p = .014), increased fiber at post (approximately 3.00A g; p = .013), and follow-up (approximately 3.00; p = .050) and decreased weight at post (approximately - 0.30 kg vs. approximately + 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.