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April 19, 2005, 2:58PM CDC: Dangers of being overweight overstated
Associated Press CHICAGO — Being overweight is nowhere near as big a killer as the
government thought, ranking No. 7 instead of No. 2 among the nation's leading
preventable causes of death, according to a startling new calculation from the
CDC. The Centers for Disease Control and Prevention estimated today that packing
on too many pounds accounts for 25,814 deaths a year in the United States. As
recently as January, the CDC came up with an estimate 14 times higher: 365,000
deaths. The new analysis found that obesity — being extremely overweight — is
indisputably lethal. But like several recent smaller studies, it found that
people who are modestly overweight actually have a lower risk of death than
those of normal weight. Biostatistician Mary Grace Kovar, a consultant for the University of
Chicago's National Opinion Research Center in Washington, said
"normal" may be set too low for today's population. Also, Americans
classified as overweight are eating better, exercising more and managing their
blood pressure better than they used to, she said. The study — an analysis of mortality rates and body-mass index, or BMI —
was published in Wednesday's Journal of the American Medical Association. Based on the new calculation, excess weight would drop from the second
leading cause of preventable death, after smoking, to seventh. It would fall
behind car crashes and guns on the list of killers. Calculating the health effects of obesity has been a major source of
controversy at the CDC. Last year, the CDC issued a study that said being overweight causes 400,000
deaths a year and would soon overtake tobacco as the top U.S. killer. After
scientists inside and outside the agency questioned the figure, the CDC admitted
making a calculation error and lowered its estimate three months ago to 365,000. CDC Director Dr. Julie Gerberding said because of the uncertainty in
calculating the health effects of being overweight, the CDC is not going to use
the brand-new figure of 25,814 in its public awareness campaigns and is not
going to scale back its fight against obesity. "There's absolutely no question that obesity is a major public health
concern of this country," she said. Gerberding said the CDC will work to
improve methods for calculating the consequences of obesity. Dr. JoAnn Manson, chief of preventive medicine at Brigham and Women's
Hospital in Boston, said she is not convinced the new estimate is right. "I think it's likely there has been a weakening of the mortality effect
due to improved treatments for obesity," she said. "But I think this
magnitude is surprising and requires corroboration." The analysis was led by Katherine Flegal, a senior research scientist with
the CDC's National Center for Health Statistics. The study that had to be
corrected was conducted by a different arm of the CDC, the Division of Adult and
Community Health, and its authors included Gerberding. One major reason for the far lower number in this latest study is that it
used more recent data, researchers said. "This analysis is far more sophisticated," said Kovar, who was not
involved in the new study. "They are very careful and are not overstating
their case." A related study, also in Wednesday's JAMA, found that overweight Americans
are healthier than ever, thanks to better maintenance of blood pressure and
cholesterol levels. Diabetes is on the rise among people in all weight
categories, however. Flegal said the two studies raise questions about what definitions to use for
obesity and "where to draw the line." Under current government
standards, a BMI, or weight-to-height measurement, of 25 or higher is
overweight; 30 and above is obese. |