A randomized controlled trial of a commercial internet weight loss program.

Objective: To assess, in a 1-year randomized controlled trial, the efficacy of eDiets.com (a commercial Internet weight loss program) in improving weight, cardiovascular health, and quality of life.

Research Methods And Procedures: Participants were 47 women with a mean age of 43.7 +/- 10.2 (SD) years and a mean BMI of 33.5 +/- 3.1 kg/m2. They were randomly assigned to either: 1) eDiets.com, a commercial Internet-based program available to the public; or 2) a weight loss manual (i.e., LEARN Program for Weight Control 2000). At baseline, participants in both groups met briefly with a psychologist who instructed them to follow the components of their program as closely as possible. Additional brief visits were provided at weeks 8, 16, 26, and 52 to review their progress. Change in weight was the main outcome measure.

Results: At week 16, participants in eDiets.com lost 0.9 +/- 3.2% of initial weight compared with 3.6 +/- 4.0% for women assigned to the weight loss manual. At week 52, losses increased to 1.1 +/- 4.0% and 4.0 +/- 5.1%, respectively. Results of a last-observation-carried-forward analysis found that women in the manual group lost significantly (p < 0.05) more weight (at both times) than those treated by eDiets.com. (Results, however, of baseline-carried-forward and completers analyses did not reach statistical significance.) There were no significant differences between groups in changes in cardiovascular risk factors or quality of life.

Discussion: This study provides consumers with important information about the probable benefits they can expect from participating in a popular Internet-based weight loss program.