Trying to lose weight can be a lonely experience. That's why many people turn to commercial weight-loss programs. But not all are created equal: A new study published in the Annals of Internal Medicine finds that Weight Watchers and Jenny Craig are the most effective programs for long-term weight loss.
“A lot of folks may consider trying out different programs, but it really has been unclear which ones have scientific evidence [supporting their efficacy],” says Dr. Kimberly Gudzune, assistant professor of medicine at Johns Hopkins University School of Medicine and an author of the study. “Out of 11, only two programs showed significant weight loss over 12 months."
Gudzune and her colleagues analyzed 39 randomized-controlled research trials for 11 commercially-available programs, from market leaders to self-directed programs. The programs they tracked include: Weight Watchers; Jenny Craig, NutriSystem, HMR, Medifast, OPTIFAST; Atkins; The Biggest Loser Club; eDiets, Lose It!; and SlimFast.
The researchers didn’t track diets like the DASH diet or the Mediterranean diet because those encourage healthful eating rather than weight loss.
- Only Jenny Craig and Weight Watchers had studies that showed weight loss that lasted 12 months or longer.
- People on these programs lost more weight than people who were in a control group, which included education and counseling.
- At a year, people using Weight Watchers experienced at least 2.6 percent greater weight loss than those who were in a control group; people using Jenny Craig experience at least 4.9 percent greater weight loss. The report didn't translate the weight loss in to how many pounds lost on average.
Weight Watchers, which costs $43 a month, helps people track their food and exercise through a points system. For $570 a month, Jenny Craig provides low-calorie, premade meals — breakfast, lunch, dinner and snacks — and support from a coach.
“No real surprises here in terms of what it shows,” says Leslie Bonci, director of sports nutrition at UPMC Center for Sports Nutrition, who was not involved in the study. “Weight Watchers not only stood the test of time, [it’s] far more reasonable than many programs.”
While Bonci sees many patients experience success with Jenny Craig, some people can’t maintain the weight loss when they start preparing their own meals.
“It’s easy when you are on it because someone gives you the food," she says. "The challenge is when you are off of it."
One of the paper’s strengths is that it clears up confusion around weight loss products, says Kristin Kirkpatrick, manager of wellness nutrition services at Cleveland Clinic Wellness Institute, who was not involved in the study.
“The weight loss industry is forever growing and it’s difficult for consumers to sort through the option and choose a plan that works,” she says. “It’s most important to find a program that fits best with your lifestyle and aligns with your overall goals.”
While the study provides data about commercial products, Dr. David Katz, director of Yale University Prevention Research Center, who was not involved with the study, says that more research needs to be conducted.
“There is clearly some weight loss benefit to a structured program as opposed to ‘no program,’” Katz writes via email.
But, there’s nothing suggesting that weight loss from these programs can be maintained past a year. One of the problems, Katz says, is that people learn how to eat on a specific plan but then face a culture obsessed with junk food.
“I’m hoping that this study actually inspires more patients to talk to their doctors about losing weight,” says Gudzune. “There is not a one-size fits all strategy [for weight loss]. For some people that maybe a commercial program.”
This article was originally published Apr. 6, 2015 at 5:30 p.m. ET.