Obesity Causes Fewer Deaths Than Previously Estimated, CDC Analysis Finds
Obesity is responsible for 112,000 deaths annually in the United States, and overweight people might live longer than people classified as being of normal weight, according to a CDC and National Cancer Institute study published Wednesday in the Journal of the American Medical Association, the Wall Street Journal reports. Researchers led by CDC senior epidemiologist Katherine Flegal analyzed data from several major federal health studies conducted between 1976 and 2000 (McKay, Wall Street Journal, 4/20).
Data was controlled for factors such as smoking, age, race and alcohol consumption using a complex analytical method based on a popular method for predicting cancer rates. Weight groups were based on body-mass index calculations.
According to the study, obesity and extreme obesity cause about 112,000 deaths annually, but being overweight was found to prevent about 86,000 deaths per year. Based on those figures, the net U.S. death toll from excess weight is 26,000 per year. By contrast, researchers found that being underweight results in 34,000 deaths per year (Kolata, New York Times, 4/20).
Flegal noted that there might have been a large number of frail elderly people in the normal-weight category, which might have affected the findings (Wahlberg, Atlanta Journal-Constitution, 4/20). The new study does not offer a reason why being slightly overweight correlated with a reduced risk of death.
Study co-author David Williamson of CDC said that most people are over age 70 when they die, and some excess weight appears to have a protective effect in old age. However, Williamson also noted that the reasons behind the "paradox" are theoretical at this point, saying, "It's raw conjecture" (New York Times, 4/20).
The new study's figures are "much lower" than a CDC report released in March 2004 that found about 400,000 deaths were related to obesity, poor diet and inactivity. That number was later reduced to 365,000 deaths after scientists found problems with the calculation methods (Hellmich, USA Today, 4/20).
The Journal reports that the most recent analysis "cast[s] even more doubts" on CDC's 2004 study (Wall Street Journal, 4/20). Flegal said the new numbers are lower because "we had different data, and our data were more recent" (USA Today, 4/20).
Donna Stroup, director of CDC's Coordinating Center for Health Promotion and an author of the 2004 study, said the agency is waiting to take an official position on excess weight and mortality risks until it hears the conclusion of an advisory panel that reviewed the two studies in December to determine which is more accurate. She added that she hopes the debate will not detract from efforts to lower obesity rates and encourage healthier lifestyles (Atlanta Journal-Constitution, 4/20).
According to the new study, obesity ranks seventh as a preventable cause of death in the United States. According to the estimates from the previous CDC research, obesity ranks as the second-leading cause (Howard Price, Washington Times, 4/20).
The new study analyzed only the risk of death and not of disability or disease related to excess weight (New York Times, 4/20). Researchers noted that the risk of death from obesity appears to be declining over time because of advances in treating heart disease, which is one of the main causes of obesity-related death (Mestel, Los Angeles Times, 4/20).
A separate paper by Williamson and CDC's Edward Gregg, also published in JAMA, examines how high blood pressure and high cholesterol levels are less prevalent than they were 30 to 40 years ago because of developments in medication to control the conditions.
Public health experts and researchers "had a full gamut of responses to the unexpected findings," the New York Times reports (New York Times, 4/20).
Flegal said, "Our numbers suggest that weight-related mortality is not as great as previously thought. But our study just looks at part of the picture. We didn't look at issues such as quality of life. These results shouldn't be overinterpreted to mean that we can all rest easy" (Barnum, San Francisco Chronicle, 4/20). She added, "I'm not sure what the public should take from it. I don't see it as the final answer to anything" (Bor/Roylance, Baltimore Sun, 4/20).
Paul Campos, a University of Colorado law professor, said, "I think this is just a bombshell. The real undeniable fact is the entire overweight definition ... is a complete spurious definition" (Los Angeles Times, 4/20).
University of Southern California sociology professor Barry Glassner said, "The take-home message from this study, it seems to me, is unambiguous. What is officially deemed overweight these days is actually the optimal weight" (New York Times, 4/20).
However, Walter Willett, chair of the department of nutrition at the Harvard School of Public Health, criticized the study's methodology, saying, "I think the papers are really naive, deeply flawed and seriously misleading. [Obesity] is a huge problem, it's getting worse fast and there's no turnaround in sight" (Los Angeles Times, 4/20).
Stroup said, "Regardless of what number you want to use, this is only a tip of the iceberg on the problem of obesity. The medical cost related to obesity is more than $93 billion a year, and we know these folks are at much greater risk of poor quality of life" (USA Today, 4/20).
The study is available online.
Instead of "focusing on gaps in personal responsibility, today's culture of complaint blames nefarious outside forces imposing bad dietary decisions on unwitting individuals as the main cause of obesity," Gary Andres writes in a Washington Times opinion piece. CATO Institute analyst Radley Balko believes such focus will lead to government regulation of restaurants and food companies and "increased litigation prompted by exotic legal theories for trial lawyers," Andres states.
However, according to a recent Dutko Worldwide survey, an "overwhelming majority of voters" believe "looking in the mirror reveals both the cause and the effect of our country's battle of the bulge," he concludes (Andres, Washington Times, 4/20).