According to an updated evidence review of 11 commercial weight-loss programs, only Weight Watchers and Jenny Craig showed evidence for effective long-term weight loss. The review was published April 7 in Annals of Internal Medicine.
More than one-third of U.S. adults are obese, according to CDC statistics.
The U.S. Preventive Services Task Force recommends clinicians screen all adults for obesity and offer or refer overweight or obese patients to intensive, multicomponent behavioral interventions for weight loss.
Several commercial weight loss programs meet the recommended criteria, but their efficacy is unclear, according to the study background.
Researchers reviewed published research to compare weight loss, adherence and harms of 11 commercial or proprietary weight loss programs with a control group that received education only or behavioral counseling. Data for the study came from a search of Medline and the Cochrane Database of Systematic Reviews. To be included in the review, studies needed to be randomized controlled trials that lasted at least 12 weeks, or, to evaluate harms, prospective case series of a year or longer.
All of the programs studied emphasized nutrition and behavioral counseling or social support components with or without physical activity. Of those, Weight Watchers, Jenny Craig, Nutrisystem, Health Management Resources, Medifast, OPTIFAST, Atkins, The Biggest Loser Club, eDiets, Lose It! and SlimFast had trials that met inclusion criteria. Researchers included a total of 45 studies, 39 of which were randomized controlled trials.
The researchers found only Jenny Craig and Weight Watchers showed evidence the programs helped people lose weight and then keep it off for a year or longer. At 12 months, Weight Watchers participants saw at least 2.6% greater weight loss than members of the control/education group, the review found. Jenny Craig participants saw at least 4.9% greater weight loss at 12 months than those assigned to the control/education and counseling groups, findings showed. Other popular programs, such as NutriSystem, showed promising weight-loss results in the short-term — at least 3.8% greater loss at three months than control/education and counseling — but additional research is needed to determine long-term results, the researchers found.
In an accompanying editorial, Christina C. Wee, MD, MPH, wrote it was not surprising that highly structured programs with in-person social support, such as Weight Watchers and Jenny Craig, seem more effective.
“Nevertheless, even with such programs, weight loss is modest and likely below patients’ expectations,” Wee wrote in the editorial. “Unrealistic expectations may affect patients’ willingness to adhere to and pay for these programs.”
Study abstract: http://annals.org/article.aspx?articleid=2214178