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).
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