Commercial Programs' Online Weight-Loss Claims Compared to Results from Randomized Controlled Trials

To characterize weight-loss claims and disclaimers present on websites for commercial weight-loss programs and compare them with results from published randomized controlled trials (RCTs).

A content analysis of all home pages and testimonials available on the websites of 24 randomly selected programs was performed. Two team members independently reviewed each page and abstracted information from text and images to capture relevant content, including demographics, weight loss, and disclaimers. A systematic review was performed to evaluate the efficacy of these programs by searching MEDLINE and the Cochrane Database of Systematic Reviews, and the mean weight change from each RCT included was abstracted.

Overall, the amount of weight loss portrayed in the testimonials was extreme across all programs examined (range median weight loss 10.7-49.5 kg). Only 10 out of the 24 programs had eligible RCTs. Median weight losses reported in testimonials exceeded that achieved by trial participants. Most programs with RCTs (78%) provided disclaimers stating that the testimonial's results were nontypical and/or gave a range of typical weight loss.

Weight-loss claims within testimonials were higher than results from RCTs. Future studies should examine whether commercial programs' advertising practices influence patients' expectations or satisfaction with modest weight-loss results.