Context: Rapid increases in access to the Internet have made it a viable mode for public health intervention. No controlled studies have evaluated this resource for weight loss.
Objective: To determine whether a structured Internet behavioral weight loss program produces greater initial weight loss and changes in waist circumference than a weight loss education Web site.
Design: Randomized, controlled trial conducted from April to December 1999.
Setting and participants: Ninety-one healthy, overweight adult hospital employees aged 18 to 60 years with a body mass index of 25 to 36 kg/m(2). Analyses were performed for the 65 who had complete follow-up data.
Interventions: Participants were randomly assigned to a 6-month weight loss program of either Internet education (education; n = 32 with complete data) or Internet behavior therapy (behavior therapy; n = 33 with complete data). All participants were given 1 face-to-face group weight loss session and access to a Web site with organized links to Internet weight loss resources. Participants in the behavior therapy group received additional behavioral procedures, including a sequence of 24 weekly behavioral lessons via e-mail, weekly online submission of self-monitoring diaries with individualized therapist feedback via e-mail, and an online bulletin board.
Main outcome measures: Body weight and waist circumference, measured at 0, 3, and 6 months, compared the 2 intervention groups.
Results: Repeated-measures analyses showed that the behavior therapy group lost more weight than the education group (P =.005). The behavior therapy group lost a mean (SD) of 4.0 (2.8) kg by 3 months and 4.1 (4.5) kg by 6 months. Weight loss in the education group was 1.7 (2.7) kg at 3 months and 1.6 (3.3) kg by 6 months. More participants in the behavior therapy than education group achieved the 5% weight loss goal (45% vs 22%; P =.05) by 6 months. Changes in waist circumference were also greater in the behavior therapy group than in the education group at both 3 months (P =.001) and 6 months (P =.005).
Conclusions: Participants who were given a structured behavioral treatment program with weekly contact and individualized feedback had better weight loss compared with those given links to educational Web sites. Thus, the Internet and e-mail appear to be viable methods for delivery of structured behavioral weight loss programs.