Systematic Review: An Evaluation of Major Commercial Weight Loss Programs in the United States

A joint task force of the National Heart, Lung, and Blood Institute and the North American Association for the Study of Obesity recently issued a guide to the assessment and treatment of obesity (1). It proposed a treatment algorithm in which diet, exercise, and behavior therapy are the cornerstone of weight management. Primary care providers, however, often feel ill equipped to provide the lifestyle modification counseling needed to facilitate weight management (2). As a result, numerous commercial and proprietary weight loss programs have been introduced (3). Practitioners are frequently asked about these programs or may wish to refer overweight persons to them. However, little published information is available to guide practitioners or consumers in the selection of a commercial weight loss program. The advertising claims of commercial programs are monitored by the Federal Trade Commission rather than the U.S. Food and Drug Administration. Programs are not required to submit data on safety or efficacy. However, the Federal Trade Commission may intervene, as it did in the early 1990s (4), when it suspects that manufacturers are making false or misleading claims. We evaluated the largest commercial and organized self-help weight loss programs in the United States by using the criteria proposed by an expert panel that was convened by the Federal Trade Commission (5). The panel recommended that commercial weight loss programs disclose information about 4 aspects of their interventions: key components of the program, qualifications of staff, costs, and risks of treatment. (Several panel members called for disclosure of outcome data, but some industry representatives indicated that they did not have adequate resources or expertise to provide such data.) These recommendations resulted in publication of the Voluntary Guidelines for Disclosure by Commercial Programs, which were designed to help consumers make informed decisions in selecting a weight loss program (5). Methods Data Sources We searched the Web sites of commercial weight loss programs for disclosure of program components and costs. If this information was not provided, we telephoned company representatives at corporate headquarters. If the representatives could not estimate program costs (principally because of geographic variation), we contacted programs in Philadelphia, Pennsylvania, for estimates. We obtained data on program efficacy by searching the MEDLINE database and manually searching the bibliographies of retrieved articles. These data were supplemented by references from a recent book (6), a descriptive review (7), a summary of industry data (8), and lists of publications received from 2 companies. This review includes any commercial program, available in the United States nationwide, for which a published evaluation of its efficacy met our criteria (specified below). We also describe the components of several national programs that have not been formally evaluated but treat large numbers of persons. Only programs that require regular in-person or online visits were considered. We included 2 organized self-help programs that offer weekly group meetings but, in contrast to commercial programs, are led by lay volunteers and are not for profit. We excluded commercial self-help approaches based on popular books, meal replacement plans, or similar products. Study Selection We searched the MEDLINE database for articles published between 1 January 1966 and 1 October 2003 by using the Medical Subject Headings obesity and weight loss, combined with each of the following terms: diet, reducing; nutrition; behavior therapy; cognitive therapy; exercise; Internet; and self-help groups. A keyword search was also conducted by combining the terms weight loss and commercial, and weight loss and proprietary. We included only studies that treated adults. Randomized trials were excluded if they were conducted outside the United States, assessed fewer than 10 participants, did not state the duration of treatment, or lasted less than 12 weeks. In addition, we included only studies in which the program was assessed under the same conditions in which it is offered to the public. For example, we excluded randomized, controlled trials of very-low-calorie diets that were conducted by investigators at academic institutions, using their own treatment protocols (9-15). We included several case series of medically supervised very-low-calorie diets because only 1 randomized trial met our review criteria. We excluded retrospective case series because such studies obtained follow-up weights for a subset of participants and then reported end-of-treatment results only for this subset, yielding biased data. We excluded case series if they did not provide the total number of patients who began treatment and instead reported only on those who completed treatment. To further increase the quality of the case series selected, we required these studies to include at least a 1-year follow-up assessment after treatment. We reviewed more than 1500 abstracts or titles of articles. We excluded more than 1400 studies because they did not assess commercial programs or were conducted outside the United States. Of the remaining 108 studies, we excluded 73 because they provided only 1 component (for example, diet) of the commercial program or because follow-up was inadequate, 10 because they lasted less than 12 weeks, 10 because they did not report the number of persons who enrolled in the program to arrive at the number described, and 5 because of miscellaneous reasons (for example, they were earlier evaluations of the same group of patients in a later study). Ten studies met our criteria to be reviewed in detail. Data Extraction Both authors reviewed the studies independently; they concurred on inclusion or exclusion in every instance. We extracted data on study type, percentage of participants who completed treatment, weight lost, duration and quality of follow-up, and maintenance of weight loss. This review examines only changes in weight. Data were insufficient to assess changes in obesity-related comorbid conditions that may have improved with weight loss. Data Synthesis We used a classification system described elsewhere (16) to characterize programs as nonmedical, medically supervised, or self-help. We added the further category Internet based. Program components, costs, and efficacy data were summarized for each program, and the results were evaluated. Statistical analyses were not performed because of the limited quantity and quality of the data. Role of the Funding Source The project was supported in part by training grants 2-T32-HP-010026 and K24-DK-065018 from the National Institutes of Health. The funding source had no role in the design, conduct, or reporting of the review. Data Synthesis Nonmedical Commercial Weight Loss Programs Staff at nonmedical commercial programs include former clients, laypersons trained by the parent company, or degree-trained professionals (such as dietitians) (Table 1). These programs do not provide physician supervision. Thus, persons with obesity-related medical complications must be monitored by their own primary care provider when participating in such interventions. Nonmedical commercial programs aim to induce weight loss of 0.4 to 0.9 kg/wk (1 to 2 lb/wk), which is considered a safe rate (1, 17). Table 1. Key Components of Selected Commercial and Organized Self-Help Weight Loss Programs Currently, the 3 largest nonmedical commercial programs in the United States are Weight Watchers, Jenny Craig, and L A Weight Loss (18-20). Tables 1 and 2 show the treatment components and costs of these programs. All 3 programs prescribe a moderately restricted diet and provide behavioral counseling, including recommendations for physical activity. However, the programs differ substantially. Weight Watchers holds large group sessions, whereas Jenny Craig and L A Weight Loss provide individual counseling. Jenny Craig also offers telephone counseling 24 hours a day, 7 days a week, as needed. Jenny Craig requires clients to purchase the company's prepackaged meals, whereas participants in Weight Watchers and L A Weight Loss consume a self-selected diet of conventional foods. The timing of payment also differs: Participants in Weight Watchers may pay weekly, whereas participants in Jenny Craig and L A Weight Loss must provide substantial payment up front (Table 2). Table 2. Estimated Program Costs for Commercial and Organized Self-Help Weight Loss Programs Outcome Data Randomized Trials. Weight Watchers has sponsored 3 randomized, controlled trials of its program. We found no such evaluations of Jenny Craig or L A Weight Loss. In a multicenter study, Heshka and colleagues (21) randomly assigned 423 participants to attend Weight Watchers weekly or to participate in a self-help intervention that included 2 visits with a dietitian (Table 3). The overall attrition rate was 27% at 2 years and was similar in both groups. Participants in Weight Watchers lost 5.3% of their initial weight at 1 year and maintained a loss of 3.2% at 2 years, compared with 1.5% and 0%, respectively, among those who received the self-help intervention (P< 0.001 at both time points). Participants in Weight Watchers who attended the most group sessions over the 2-year study period maintained the largest weight losses at the end of this period; this finding underscores the importance of adherence to behavior strategies. Table 3. Summary of Results for Commercial and Organized Self-Help Weight Loss Programs In a single-site study, 48 women with a history of breast cancer were randomly assigned to receive usual care, attend a weekly group Weight Watchers meeting, undergo individual counseling with a dietitian, or receive both of the latter 2 interventions (22). The attrition rate across the 4 groups was 19% at 1 year; the investigators did not state whether this rate differed among groups. At 1 year, p