Researchers: Chronic Dieting Doesn’t Appear Dangerous After All
CHICAGO (AP) _ Yo-yo dieting, or losing weight only to gain it back, doesn’t appear to be dangerous after all, researchers reported Wednesday.
A task force of nutritionists, behavioral scientists and researchers from the National Institutes of Health reviewed nearly 30 years of data and found much of it flawed.
The panel said in The Journal of the American Medical Association that it’s more dangerous to be overweight than to worry about unfounded health risks from yo-yo dieting.
″It’s now gotten to the point where many people are saying it’s better to be overweight, despite the fact we know obesity is associated with″ problems ranging from heart disease to cancer, said Dr. Susan Z. Yanovski, a task force member and researcher at NIH in Bethesda, Md.
The past research indicated yo-yo dieting may disrupt metabolism, increase body fat and lead to heart problems and other health risks.
But the 13-member National Task Force on the Prevention and Treatment of Obesity found otherwise.
″There is no convincing evidence that weight cycling in humans has adverse effects on body composition, energy expenditure, risk factors for cardiovascular disease or the effectiveness of future efforts at weight loss,″ the report said.
Yanovski said in a telephone interview that previous studies failed to consider all factors associated with chronic dieting. Most of the past research failed to determine the effects in significantly obese people, the task force said.
And previous studies didn’t take into account unintentional weight loss due to unsuspected medical problems, such as cancer. Other health problems that caused weight loss and gain could have been attributed to the dieting itself, the panel said.
Forty percent of women and 25 percent of all men in the United States have reported trying to lose weight at some point in their lives.
More study taking into account all factors is needed to determine any long- term health effects of yo-yo dieting, the researchers said.
″The good news is that small weight losses, even five or 10 pounds, can have significant health benefits,″ Yanovski said.
Dr. Edward Mascioli, a Harvard Medical School nutrition expert who wasn’t involved in the review, said he supports the task force’s conclusions.
″I’ve felt all along that the data was lacking,″ he said.
Some studies ″have shown a decrease in risk factors with weight loss, but if they regain the weight, those risk factors come back,″ Mascioli said.
That, he said, doesn’t mean there is an inherent danger in losing and regaining weight. Rather, Mascioli said, the risk lies in being overweight in the first place.