Almost No Evidence Exists To Prove Effectiveness of Commercial Weight-Loss Programs, Study Finds
Almost no evidence exists to show that most commercial weight-loss programs are effective in reducing weight, according to a study in the Annals of Internal Medicine, the New York Times reports.
Thomas Wadden, director of the weight and eating disorders program at the University of Pennsylvania, and colleagues examined information on prices, methods and results for nine commercial weight-loss programs -- including eDiets, Jenny Craig, Optifast and Weight Watchers -- as well as self-help programs like Overeaters Anonymous.
Wadden and colleagues looked at studies published from 1966 to 2003 and found 108 that assessed commercial weight-loss programs. Of those, 10 met their scientific criteria, such as tracking enrollees for at least 12 weeks and assessing outcomes after a year. The study found that Weight Watchers was the only program to have published reliable data using randomized trials to show that participants weighed less a few months after beginning the program than people who did not participate, "and even in the Weight Watchers study ... the results were modest," the Times reports.
Although researchers found no adequate evaluations of Jenny Craig, Kent Coykendall, a vice president of strategic planning and business development at Jenny Craig, said there was "a plethora of real data on real people in the real world under real circumstances" (Kolata , New York Times, 1/4). The study's authors "stressed" that the study "should not be viewed as an attack on diet programs," the AP/Long Island Newsday reports.
"There are no data on weight loss when you go to a health club, either," Wadden said, adding, "We hope that doctors and patients will use this information to make more informed decisions" (Loviglio, AP/Long Island Newsday, 1/3).
An abstract of the study is available online.
A separate study, published in the December issue of the Journal of General Internal Medicine, found that 33% of obese people and 19% of overweight people would risk death for an effortless 10% loss in weight, the New York Times reports. By comparison, 4% of normal-weight people said they would risk death for a 10% weight loss.
In addition, 31% of obese patients and 8.3% of overweight patients said they would trade up to 5% of their remaining lives to lose 10% of their weight. The study, conducted by Harvard Medical School internist Christina Wee and colleagues, surveyed 366 patients, 33% of whom were overweight and 27% of whom were obese.
Wee said it "was very surprising" to her that patients wanted so badly to lose even modest amounts of weight (Kolata , New York Times, 1/4).
The study is available online.