Friday, April 22, 2005


First note this challenge from the CCF:

Stop stonewalling:

"The Centers for Disease Control and Prevention (CDC) still insists on using its deeply flawed study purportedly showing that obesity kills 400,000 Americans each year. And so the Center for Consumer Freedom must ask them again to set the record straight. The CDC should get the weight of its blemished obesity study off its chest, and help prevent frivolous and unnecessary regulation and litigation. Click here for a complete timeline of events surrounding the CDC's study. [timeline] ... Even as a mountain of evidence -- growing by the day -- further strains the CDC's credibility, the agency has yet to retract its flawed and most likely politically motivated obesity deaths number. We're left demanding: CDC, come clean, and stop using this flawed and exaggerated statistic."

Then this:


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 Tuesday 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. In recent years, the government has spent millions of dollars fighting obesity and publicizing the message that two out of three American adults are overweight or obese, and at higher risk for heart disease, arthritis and diabetes.


And finally this:


Being overweight may not be as dangerous as it is generally portrayed, a new study in the United States has found. Those who are only moderately overweight have a lower relative risk of death than those of supposedly optimum weight, the results show. Modest obesity - a body mass index of 30 to 35 - increases the risks of dying only slightly, leaving only the grossly obese, with a body mass index greater than 35, with a greatly increased risk.

While it may be fashionable to be extremely skinny, it does nothing to prolong life. The risks of dying among people with a body mass index of less than 18.5 are slightly increased. The results, published in the Journal of the American Medical Association, have been lauded by some specialists as a useful corrective to the national panic in America over obesity. Steven Blair, of the Cooper Institute in Dallas, Texas, said: "I love it. There are people who have made up their minds that obesity and overweight are the biggest public health problem we have to face. These numbers show that maybe it's not so big."

However, the study, by a team led by Katherine Flegal, of the US National Centre for Health Statistics, is limited in its conclusions. It looked only at deaths, not at disease or disability, which generally increase with weight. Earlier studies have shown that being moderately overweight is not necessarily a bad thing and that being grievously thin is a hazard, so the new results will not astonish experts. Nevertheless, the study is larger and more comprehensive than earlier ones.

The team used data from three US National Health and Nutrition Examination Surveys, carried out in the 1970s, 1980s and 1990s. These surveys measured body mass index in a representative sample of the American population, then followed them, recording deaths as they occurred.

More here

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