Studies show you'll lose lbs. on Jenny Craig, Weight Watchers

CHICAGO - Trying to slim down? Weight Watchers and Jenny Craig scored the best marks for effectiveness in a review of research on commercial diet programs, but many other plans just haven't been studied enough to evaluate long-term results.

The two plans are among the most popular and had the best evidence that dieters could lose meaningful amounts of weight and keep it off for at least a year, the review authors said.

Pooling results from several studies, the researchers found that Weight Watchers dieters lost an average of at least eight pounds and kept it off for at least 12 months vs. about 15 pounds for those using the Jenny Craig plan.

Most participants remained overweight, with weight loss of between 3 percent and 5 percent of their initial weight - but that's a range that doctors typically recommend to achieve healthful benefits including lower blood pressure and cholesterol levels.

"It's a really important first step to reach," even if it doesn't meet patients' expectations, said study author Dr. Kimberly Gudzune, an internist and researcher at Johns Hopkins University's medical school.

The study was published Monday in Annals of Internal Medicine.

The research review included 39 rigorous studies involving 11 popular diet programs that include support or counseling services and involve fees for products or services. Most studies compared the programs with standard diet information or behavioral counseling that patients get from health-care providers; long-term results for Weight Watchers and Jenny Craig were mostly better than the comparisons.

The researchers didn't attempt to make head-to-head comparisons of different diet plans.

Diet companies had no role in the research, Gudzune said.

Weight Watchers and Jenny Craig include behavioral counseling, coaching or social support - important for long-term weight-loss success, according to an Annals editorial.

Weight Watchers costs about $43 monthly, which includes costs for attending online or in-person support groups or coaching sessions. Participants can buy the company's low-calorie products or buy their own food, but each item is assigned points and dieters aim not to exceed a daily point limit.

Jenny Craig provides premade meals and costs about almost $600 monthly.