This may come as no surprise, but most weight-loss programs, despite what they say, don't work, researchers officially announced in a new study.
According to findings recently published in the journal Annals of Internal Medicine, only a few dozen commercial weight-loss programs have shown that their users lose more weight compared to those who don't use them. This could help physicians guide obese and overweight patients who want to try their hand at popular programs such as Atkins or SlimFast.
"Primary care doctors need to know what programs have rigorous trials showing that they work, but they haven't had much evidence to rely on," Kimberly Gudzune, an assistant professor of medicine and a weight-loss specialist at the Johns Hopkins University School of Medicine, said in a statement. "Our review should give clinicians a better idea of what programs they might consider for their patients."
The researchers reviewed 4,200 studies for solid evidence of their effectiveness, and found that of 32 major commercial weight-loss programs marketed nationwide, only 11 have been rigorously studied in randomized controlled trials. And from these studies, apparently only two programs met the scientific gold standard of reliability - meaning that, on average, participants lost more weight after one year in these programs than people who were either dieting on their own, got printed health information, or received other forms of education and counseling sessions.
What's more, people enrolled in these programs only lost a "moderate" amount of weight, which is between three and five percent more compared to a control group.
The weight-loss programs looked at in this study were high-intensity programs such as Weight Watchers, Jenny Craig and NutriSystem - which incorporate goal setting, self-monitoring, nutritional information and counseling - and low-calorie meal replacement programs like HMR, Medifast and OPTIFAST. Five self-directed programs were also examined, including Atkins and SlimFast.
"Clinicians could consider referring patients who are overweight or obese to Weight Watchers or Jenny Craig. Other popular programs, such as NutriSystem, show promising weight-loss results, but additional studies evaluating long-term outcomes are needed," the researchers wrote.
Most studies, the researchers also noted, don't look at weight loss 12 months and beyond, which is important in order to determine whether or not participants were able to maintain their weight loss over the long term.
"We want people to experience the health benefits of weight loss - lower blood pressure, cholesterol and blood sugar, and lower risk of developing diseases like diabetes," added study co-author Jeanne Clark. "Those benefits are long-term goals; losing weight for three months, then regaining it, has limited health benefits."
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