Compared to no intervention or minimal interventions (pamphlets, usual care), interactive computer-based interventions are an effective intervention for weight loss and weight maintenance. Compared to in-person interventions, interactive computer-based interventions result in smaller weight losses and lower levels of weight maintenance. The amount of additional weight loss, however, is relatively small and of brief duration, making the clinical significance of these differences unclear.
Weight management using the internet a randomized controlled trial.
Most weight-loss research targets obese individuals who desire large weight reductions. However, evaluation of weight-gain prevention in overweight individuals is also critical as most Americans become obese as a result of a gradual gain of 1-2 pounds per year over many years.
                This study evaluated the efficacy of an Internet-based program for weight-loss and weight-gain prevention with a two-group, prospective, randomized controlled trial. A military medical research center with a population of 17,000 active-duty military personnel supplied 446 overweight individuals (222 men; 224 women) with a mean age of 34 years and a mean BMI of 29. Recruitment and study participation occurred 2003-2005 and data were analyzed in 2006. Participants were randomly assigned to receive the 6-month behavioral Internet treatment (BIT, n=227) or usual care (n=224). Change in body weight, BMI, percent body fat, and waist circumference; presented as group by time interactions, were measured.
                After 6 months, completers who received BIT lost 1.3 kg while those assigned to usual care gained 0.6 kg (F((df=366))=24.17; I<0.001). Results were similar for the intention-to-treat model. BIT participants also had significant changes in BMI (-0.5 vs +0.2 kg/m(2); F((df=366))=24.58); percent body fat (-0.4 vs +0.6%; F((df=366))=10.45); and waist circumference (-2.1 vs -0.4 cm; F((df=366))=17.09); p<0.001 for all.
                Internet-based weight-management interventions result in small amounts of weight loss, prevent weight gain, and have potential for widespread dissemination as a population health approach.
                NCT00417599.