Development of Internet weight loss programs may be a viable method for reducing the public health burden of obesity. The purpose of this study was to evaluate the efficacy of the Internet for delivery of weight control programs. Participants (10M, 81F; age=40.9; BMI=29.0) were randomly assigned to receive Internet Behavior Therapy (IBT, n=46) or an Internet Education program (IEd, n=45). Participants in IEd were given an initial face-to-face meeting and directed to weight loss related websites they could use to develop their own weight loss program, but were given no further help to do this. Participants in IBT received this meeting, access to the same website resources plus additional behavioral procedures, all delivered via Internet and e-mail, including a sequence of weekly behavioral weight loss lessons; prompting for submission of weekly self-monitoring diaries; personalized feedback; and an on-line bulletin board for social support.

Attrition (15%) was not different between conditions. Weight losses measured at 12 weeks were significantly greater for IBT (-9.0 lbs ± 5.9lbs) than IEd (-2.98 lbs ± 5.7lbs; p<.001). Furthermore, significantly more participants in IBT lost ≥ 1 pound per week (32% IBT vs. 13% ISH; p<.05). Participants in IBT also logged into the website significantly more often than those in IEd (19.7 ± 10.3 times vs. 9.6 ± 10.5 times; p<.001). Simply providing access to weight loss related websites produced minimal weight loss. However, an Internet program incorporating behavioral procedures appears a promising new weight loss approach.