Primary Care Referral to a Commercial Provider for Weight Loss Treatment Versus Standard Care: A Randomised Controlled Trial

Study Questions:

Does referral by a primary care provider to a commercial weight loss program result in effective weight reduction?


This was a nonblinded, randomized, controlled trial of overweight and obese adults recruited from primary care practices in three countries. Participants were recruited from 39 primary care practices in Germany, 70 practices in Australia, and six practices in the United Kingdom between Sept 10, 2007, and November 28, 2008. Subjects were randomly assigned to usual care or 12 months of a free membership to a commercial weight loss program (Weight Watchers). Follow-up continued for 12 months. The primary outcome of interest was change in weight. Additional outcomes included blood pressure, lipid profiles, and waist circumference.


A total 772 subjects were enrolled in the study, of which 377 subjects were randomized to the Weight Watchers commercial program. A total of 230 participants (61%) in the commercial intervention completed the 12-month assessment, and 214 (54%) of the usual care group completed the 12-month program. Participants in the commercial program lost more weight than those in the usual care group. The mean weight change at 12 months was 5.06 kg (standard error, 0.31) for those in the commercial program compared to –2.25 kg (0.21) for those receiving usual care (adjusted difference, –2.77 kg; 95% confidence interval [CI], –3.50 to –2.03). Participants assigned to the commercial program had increased odds of losing 5% or more (odds ratio [OR], 3.0; 95% CI, 2.0-4.4) and 10% or more (OR, 3.2; 95% CI, 2.0-5.3) initial weight at 12 months than did those assigned to standard care. Participants in the commercial program had significantly greater improvements in insulin and ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol than did those assigned to standard care. Improvements in glucose, and HDL and low-density lipoprotein cholesterol levels among those in the commercial program were observed, which did not research statistical significance. Small reductions in blood pressure in both treatment groups were also observed; no significant difference between the groups was noted. Participants reported no adverse events related to trial participation.


The investigators concluded that referral to a commercial weight loss program can improve weight loss among patients who are obese or overweight.


This study suggests that commercial programs can assist patients to lose weight. However, the dropout rate in this study was high, suggesting large-scale adoption may be limited. Furthermore, the cost of such programs may be a factor for many patients. Last, despite the popularity of programs such as Weight Watchers in the United States, the rates of overweight and obese adults continue to grow. This suggests that additional measures beyond referral to a commercial program are needed.

Clinical Topics: Dyslipidemia, Lipid Metabolism, Nonstatins

Keywords: Overweight, Weight Loss, Referral and Consultation, Vascular Diseases, Body Weight, Blood Pressure, Cholesterol, Waist Circumference, Weight Reduction Programs, Obesity, Confidence Intervals, Primary Health Care

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