Guide to health: a randomized controlled trial of the effects of a completely web-based intervention on physical activity, fruit and vegetable consumption, and body weight

Theory-based, efficacious, long-term, completely Internet-based interventions are needed to induce favorable shifts in health behaviors and prevent weight gain. To assess nutrition, physical activity and, secondarily, body weight outcomes in the tailored, social cognitive theory Guide to Health (web-based Guide to Health, WB-GTH) program with all recruitment, assessment, and intervention performed on the Internet. The focus of the efficacy study was engaged participants who completed three or more program modules plus baseline and 6-months post-and 16-months follow-up assessments (n= 247). To be eligible, participants needed to be between 18 and 63 years of age, with a BMI between 23 and 39, sedentary to low-active but otherwise healthy. Participants had a mean age of 45.5 years (10.3), 86.2% were female, with 8.5% from minority groups, with a mean 17.5 (3.0) years of education, and had a median annual household income of about $ 85,000. Nevertheless, about 83% were overweight or obese and about 75% were sedentary (i. e., < 5,000 steps/day) or had low levels of activity (i. e., 5,000-7,499 steps/day). Participants were randomized to the WB-GTH-Basic intervention or WB-GTH-Enhanced intervention. Content, overall target behaviors, program goals, and strategies were the same in the two interventions with the difference that Basic included a generic feedback and planning approach and Enhanced included a highly tailored planning and feedback approach. Participants reported at assessments pedometer step counts to assess physical activity, bodyweight froma scale provided, and fruit and vegetable (F& V) servings were assessed from food frequency questionnaires completed online. Participants in both Basic and Enhanced at follow-up increased physical activity by about 1,400 steps/day, lost about 3% of bodyweight, and increased F& V by about 1.5 servings/day. There was evidence that the least physically active, those who were obese, and those with poorest nutrition made greater long-term improvements. Given similar outcomes for Basic and Enhanced, a relatively simple entirely Internet-based program can help people improve health behaviors and prevent weight gain.