Objective: Internet weight loss programs have become widely available as alternatives to standard treatment, but few data are available on their efficacy. This study aimed to investigate the effectiveness of a structured behavioral weight loss website (VTrim) vs. a commercial weight loss website (eDiets.com).
Research methods and procedures: A randomized, controlled trial was conducted from February 2003 to March 2005, in 124 overweight and obese subjects ages 18 years and older with a BMI of 25 to 39.9 kg/m2 (mean age, 47 +/- 9 years; BMI, 32 +/- 3 kg/m2; 20% men). Analyses were performed for the 88 subjects who had complete follow-up data. Participants were randomly assigned to 12-month VTrim (n = 62) or eDiets.com (n = 62) intervention. VTrim participants had access to a therapist-led structured behavioral weight loss program delivered on-line. eDiets.com subjects had access to a self-help commercial on-line weight loss program. Body weight, social support, and use of website components were measured at 0, 6, and 12 months.
Results: Repeated-measures analyses showed that the VTrim group lost significantly more weight than the eDiets.com group at 6 months (8.3 +/- 7.9 kg vs. 4.1 +/- 6.2 kg; p = 0.004) and maintained a greater loss at 12 months (7.8 +/- 7.5 kg vs. 3.4 +/- 5.8 kg; p = 0.002). More participants in the VTrim group maintained a 5% weight loss goal (65% vs. 37.5%; p = 0.01) at 12 months.
Discussion: An on-line, therapist-led structured behavioral weight loss website produced greater weight loss than a self-help commercial website. Because commercial sites have great potential public health impact, future research should investigate the feasibility of incorporating a more structured behavioral program into a commercial application.