Retention rates and weight loss in a commercial weight loss program [Erratum: 2007 Feb., v. 31, no. 2, p. 394.]

Objective: To evaluate and describe retention rates and weight loss in clients participating in a commercial weight loss program. Subjects: A total of 60 164 men and women ages 18-79 years who enrolled in the Jenny Craig Platinum program between May 2001 and May 2002. Methods: Retention rates, mean weight loss and percent weight loss were calculated on a weekly basis for the 52-week period following initial enrollment in the weight loss program. Clients were categorized based on final week of participation in the program (weeks 1-4, weeks 5-13, weeks 14-26, weeks 27-39 and weeks 40-52) and weight loss was calculated at final week. A subgroup of clients was identified based on attendance through 13, 26 and 52 weeks. Mean and percent weight loss was calculated for these subgroups of clients. Results: Of the 60 164 men and women who enrolled in the weight loss program, 73% were retained in the program after 4 weeks, 42% at 13 weeks, 22% at 26 weeks and 6.6% at 52 weeks. Clients who dropped out of the program during the first 4 weeks lost 1.1+/-1.6% (mean+/-s.d.) of their initial body weight, whereas clients who dropped out between 40 and 52 weeks lost 12.0+/-7.2%. Clients in the 13-week, 26-week and 52-week cohorts lost 8.3+/-3.3, 12.6+/-5.1 and 15.6+/-7.5% of their initial body weight, respectively. Conclusion: Weight loss was greater among clients who were retained in the program longer. The findings from this study suggest that a commercial weight loss program can be an effective weight loss tool for individuals who remain active in the program.