Background Commercial or proprietary weight loss programs are popular obesity treatment options; however, their efficacy is unclear. Purpose To compare weight loss, adherence, and harms of commercial or proprietary weight loss programs to control/education or behavioral counseling among adults with overweight and obesity. Data sources MEDLINE and Cochrane Database of Systematic Reviews from inception to November 2014; references identified by programs Study selection Randomized controlled trials (RCT) of ≥12 weeks duration; prospective case series ≥12 months (harms only) Data extraction Two reviewers extracted information on study design, population characteristics, interventions, and mean % weight change, and assessed risk of bias. Data synthesis We included 39 RCTs. At 12 months, Weight Watchers’ participants achieved at least 2.6% greater weight loss than control/education. Jenny Craig resulted in at least 4.9% greater weight loss at 12 months as compared to both control/education and counseling. Nutrisystem participants achieved at least 3.8% greater weight loss at 3 months than control/education or counseling. Very-low-calorie programs (HMR, Medifast, Optifast) resulted in at least 4.0% greater short-term weight loss than counseling, but some attenuation of effect occurred beyond 6 months when reported. Atkins achieved 0.1–2.9% greater weight loss at 12 months than counseling. Results for SlimFast were mixed. We found limited evidence to evaluate adherence or harms for all programs and weight outcomes for other commercial programs. Limitations Many trials had short durations (<12 months), high attrition, and lacked blinding. Conclusions Clinicians could consider referring patients with overweight or obesity to Weight Watchers or Jenny Craig. Other popular programs such as NutriSystem show promising weight loss results; however, additional studies evaluating long-term outcomes are needed. Primary funding source None. Registered with PROSPERO (CRD42014007155).

OBJECTIVE -There is a concern that an "epidemic of obesity" is occurring in Western societies. One consequence of obesity is that type 2 diabetes may develop. Presumably, a great increase in body weight would continue in people with diabetes and may be accelerated due to pharmacological treatment. In this retrospective study, we tested the hypothesis that the weight gain in a diabetic population is greater than that in the general population.RESEARCH DESIGN AND METHODS -Data were obtained from the records of 205 adult men who have attended a diabetes clinic for Ն5 years. Their weight and glycohemoglobin at the last visit were compared with the initial visit data. The subjects were categorized according to treatment modalities. The mean follow-up was 9.4 years (range 5-23).RESULTS -For the group as a whole, the mean increase in body weight was 0.23 Ϯ 0.2 kg/year. BMI or initial age had little effect on the rate of weight gain. Treatment regimen used did have an effect on weight change. In subjects treated with insulin, with or without oral agents, body weight increased at a rate of 0.44 Ϯ 0.1 kg/year. In subjects treated with metformin or metformin and a sulfonylurea, there was a mean loss in weight, i.e., Ϫ0.24 Ϯ 0.09 kg/year, and with sulfonylureas alone weight increased by 0.42 Ϯ 0.2 kg/year. CONCLUSIONS -The men treated with insulin alone or insulin combined with oral agents gained weight at a rate comparable with that reported for the general population, i.e., the weight gain was not extraordinary. Metformin treatment resulted in a modest loss of weight. Diabetes Care 29:493-497, 2006

Our objective was to compare the effect of commercial weight-loss programs on blood pressure and lipids to control/education or counseling among individuals with overweight/obesity. We conducted a systematic review by searching MEDLINE and Cochrane Database of Systematic Reviews from inception to November 2014 and references identified by the programs. We included randomized, controlled trials ≥12 weeks duration. Two reviewers extracted information on study design, interventions, and mean change in systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), triglycerides, and total cholesterol and assessed risk of bias. We included 27 trials. Participants’ blood pressure and lipids were normal at baseline in most trials. At 12 months, Weight Watchers showed little change in blood pressure or lipid outcomes as compared to control/education (2 trials). At 12 months, Atkins’ participants had higher HDL-c and lower triglycerides than counseling (4 trials). Other programs had inconsistent effects or lacked long-term studies. Risk of bias was high for most trials of all programs. In conclusion, limited data exist regarding most commercial weight-loss programs’ long-term effects on blood pressure and lipids. Clinicians should be aware that Weight Watchers has limited data that demonstrate CVD risk factor benefits relative to control/education. Atkins may be a reasonable option for patients with dyslipidemia. Additional well-designed, long-term trials are needed to confirm these conclusions and evaluate other commercial programs.

Objective We examined the glycemic benefits of commercial weight-loss programs as compared to control/education or counseling among overweight and obese adults who had or who were at increased risk for type 2 diabetes mellitus (T2DM). Methods We searched MEDLINE, Cochrane Database of Systematic Reviews, and references cited by individual programs. We included randomized controlled trials (RCTs) of ≥12 weeks duration. Two reviewers extracted information on study design, population characteristics, interventions, and mean changes in hemoglobin A1c and glucose. Results We included 18 RCTs. Few trials occurred among individuals with T2DM. In this population, Jenny Craig reduced A1c at least 0.4% more than counseling at 12 months, Nutrisystem significantly reduced A1c 0.3% more than counseling at 6 months, and OPTIFAST reduced A1c 0.3% more than counseling at 6 months. Among individuals at increased risk for T2DM, few studies evaluated glycemic outcomes, and when reported, most did not show substantial reductions. Discussion Few trials have examined whether commercial weight-loss programs result in glycemic benefits for their participants, particularly among individuals at increased risk of T2DM. Jenny Craig, Nutrisystem, and OPTIFAST show promising glycemic lowering benefits for patients with T2DM, although additional studies are needed to confirm these conclusions.