Weight loss poses risk, study says
Overweight people who are otherwise healthy may increase their risk of dying by intentionally losing weight, according to provocative new research.
A study of 2,957 twins in Finland found that those who were overweight who lost weight on purpose were about 86 percent more likely to die for any reason over the next 18 years compared with those whose weight remained stable.
The researchers cautioned, however, that only 268 people in the study died, a number too small to justify any firm recommendations about whether overweight people should try to lose weight.
Skeptics who think health authorities have exaggerated the risks of being overweight said the findings offer fresh support. Other researchers, however, said the study’s weaknesses undercut the findings, and there is overwhelming evidence that being overweight increases the risk of a host of health problems.
The researchers who conducted the study said they hope the results will stimulate more research into the relative risks and benefits of losing weight.
“We think that our findings are scientifically significant because they clearly demonstrate that the relation between intentional weight loss and subsequent health effects is complex and needs much more research,” said Thorkild I.A. Sorensen of Copenhagen University Hospital.
Sorensen and his colleagues studied twins who had undergone detailed questioning in 1975 about various health issues, including whether they intended to try to lose weight. Over the next 18 years, those who were overweight and lost weight on purpose ended up being more likely to die than those who did not slim down, and the risk increased with the amount of weight lost, the study found. The increased risk held true even after the researchers took into consideration factors such as how much the subjects exercised, what they ate and whether they had any health problems.
“We cannot say that they should not lose weight, only that we, due to our findings, are in doubt about the possible adverse long-term effects,” Sorensen said in an e-mail.
The study was published in the Public Library of Science journal PLoS Medicine. Sorensen said his team previously tried to publish the study in other journals, including the New England Journal of Medicine and the Journal of the American Medical Association.
“We were left with the impression that they perhaps did not like to distribute such (a) message,” Sorensen wrote.
Other researchers praised the study for exploring the question.
“It is one of the few studies that addresses this issue,” said Katherine Flegal of the federal Centers for Disease Control and Prevention, who ignited a controversy in April when she published a study that concluded that her agency had overestimated the negative effects of obesity. “It suggests there may be more to this than people think.”