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An Epidemic of Obesity Myths
Timeline of a Great Unraveling

March 9, 2004 — The heads of the Department of Health and Human Services, the Centers for Disease Control and Prevention, and the National Institutes of Health announce a study published in JAMA attributing 400,000 deaths in the year 2000 to poor diet and physical inactivity.

March 31, 2004 — CDC director Julie Gerberding requests $6.9 billion from Congress for the agency’s 2005 budget, saying:
"[W]e must also remain vigilant against long-standing public health concerns like physical inactivity and poor nutrition. Together these account for an estimated 400,000 deaths per year in this country."
May 7, 2004Science magazine reports that "some researchers, including a few at CDC, dismiss [the CDC’s 400,000-deaths statistic], saying the underlying data are weak." The article continued:
"They argue that the paper’s compatibility with a new antiobesity theme in government public health pronouncements—rather than sound analysis—propelled it into print… Several epidemiologists at CDC and the National Institutes of Health (NIH) echoed [these concerns] but declined to speak on the record. �I don’t want to lose my job,’ said one CDC staffer who does research in the area. Critics also object that the authors added an arbitrary number of deaths from poor nutrition (15,000) to the obesity category. A CDC scientist says internal discussions on these issues got �very contentious’ months before publication and left some feeling that the conclusions were not debatable."
June 21, 2004 — Congressman Henry Waxman (D-CA) formally requests a Government Accountability Office investigation of the CDC’s death estimate.

June 23, 2004 — CDC National Center for Chronic Disease Prevention and Health Promotion acting director Dr. George Mensah asks the CDC’s Dr. Stephen Thacker to conduct an internal review of the 400,000-deaths study.

August 15, 2004 — CDC researchers Katherine Flegal and David Williamson and National Institutes of Health researcher Barry Graubard co-author a study in The American Journal of Epidemiology critiquing the method used in the CDC’s original study. The authors conclude:
"Existing estimates of the number of deaths attributed to overweight and obesity were calculated by using a method likely to produce biased estimates, when the effects of obesity vary by age or other characteristics. Estimates of deaths attributable to overweight and obesity arrived at by using this approach may be biased and should be viewed cautiously."
A second paper—published in The American Journal of Public Health by Flegal, Williamson, and two other CDC researchers—also criticizes the 400,000-deaths paper’s methods. The authors warn:
"Our examination suggests that given present knowledge about the epidemiology of obesity, and especially the impact of age on mortality risks associated with obesity, it may be difficult to develop accurate and precise estimates. We urge caution in the use of current estimates on the number of deaths attributable to obesity and also urge researchers to devote greater efforts to improve the data and methods used to estimate this important public health statistic."
Significantly, both studies were submitted for publication in 2003, months before the 400,000-deaths study appeared in JAMA.

October 2004 — The CDC committee reviewing the 400,000-deaths study submits its findings to the agency’s Chief of Science. The report is not released publicly.

November 23, 2004 — The Wall Street Journal publishes a front-page story on errors in the 400,000-deaths study.

December 3, 2004 — A follow-up article in The Wall Street Journal reveals additional problems with the CDC’s methodology:
"Critics of the study say the estimate was intiated not just by the statistical mistakes the CDC acknowledged last week, but also by the authors’ scientific approach. The number of obesity-related deaths could be less than half of the 400,000 estimated in the . awed CDC study, according to some scientists familiar with the debate."
University of Alabama professor David Allison, who developed the methodology used in the CDC study, admits in the story that measuring obesity-attributable deaths "is an evolving science."

January 18, 2005 — The CDC publishes an erratum in JAMA admitting to a mathematical error. The estimate of overweight- and obesity-attributable deaths is lowered to 365,000 per year.

January 19, 2005The Wall Street Journal reports on the CDC’s correction, noting:
"The CDC hopes to put behind it not only the embarrassment of the computational errors but the controversy over the high-profile study that began simmering inside the agency even before it was published. Some scientists at the CDC expressed misgivings about the study’s methodology and findings before publication, and complained that their comments were ignored, according to internal documents and people familiar with the debate. They warned that the approach the authors were using didn’t take into account recent advances in methodology and could intiate the final obesity tally."
The Journal also reports that the CDC refused to release the full internal report:
"After criticism of the original study surfaced among scientists last spring, CDC director Julie Gerberding, one of the study’s four authors, ordered an inquiry. That probe has also been completed, though the CDC wouldn’t release a copy of its final report yesterday."
February 9, 2005 — The CDC’s internal review committee releases a summary of its report, which concludes that the underlying methodology used to estimate obesity-attributable deaths had significant limitations:
"The paper published by Mokdad, et al., Actual Causes of Death in the United States, 2000, has provoked significant controversy both inside and outside the agency. While there was at least one error in the calculations and both the presentation of the paper and limitations of the approach could have been expressed more clearly, the fundamental scientific problem centers around the limitations in both the data and the methodology in this area." (emphasis added)

The report also notes: "The scientists expressed concerns and did meet with some of the authors but they were not convinced that their perspectives were listened to or that requests for data were acknowledged."

February 25, 2005 — Responding to an op-ed by the Center for Consumer Freedom calling on the CDC to formally retract its embattled 400,000-deaths study, CDC Chief of Science Dixie Snider writes in The Atlanta Journal-Constitution: "…we cannot and should not let this discussion of scientific methodology detract from the real issue." According to the CDC’s website, Snider’s job is "maintaining the integrity and productivity of CDC’s scientists by resolving controversial scientific issues."

In spite of the fanfare with which the CDC announced its original finding of 400,000 annual obesity-related deaths, Snider adds, "we should not let the focus on deaths attributable to obesity distract us from this serious health issue."

February 28, 2005 — Following Snider’s astounding comments, the editorial board of The Washington Times joins CCF in calling on the CDC to publicly retract the flawed study. Describing Snider’s comments as "dangerous reasoning," the Times editorial argues:


April 20, 2005 — A team of researchers from the CDC and the NIH publish a bombshell study in JAMA attributing 25,814 deaths to obesity and overweight annually. The study stands in stark contrast to the CDC’s original estimate, which was 15 times higher. CDC Chief of Science Dixie Snider says the agency won’t take a position on the new study, insisting, "We’re too early in the science." The Associated Press reports:
"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."
April 22�May 10, 2005 — Opinion leaders across the country take the CDC to task for its handling of the obesity-death estimate. The editorial board of The New York Times writes:


A Washington Post editorial wrote:


May 6, 2005Science magazine reports: "Scientists agree that Flegal’s study is superior."

May 19, 2005Scientific American prints an article titled "Obesity: An Overblown Epidemic?" questioning much of the hype about obesity.

May 25, 2005 — The CDC responds to a Freedom of Information Act request by CCF and releases the agency’s internal review committee report.

In the report, a number of the committee members suggested that the CDC submit an official correction to JAMA regarding the methodological problems. One wrote: "If possible, the proper formula should be used to calculate the deaths attributed to obesity. If using the published assumptions but the more suitable equation leads to different estimates, an erratum should be submitted." Yet the CDC’s subsequent erratum to JAMA, which lowered the estimate to 365,000 deaths, only addressed mathematical errors—and not the substantial methodological problems raised in the review committee’s report.

The report also indicates that the authors of the original study apparently knew they were using the "wrong formula" before the study was published.

May 31, 2005 — In a new "frequently asked questions" document posted on the agency’s Web site, the CDC writes: "Is CDC changing its estimate of obesity-related deaths? Yes. We are no longer going to use the previous annual estimate of 365,000 deaths from poor nutrition and physical inactivity. Instead, CDC will state, �The latest study based on a nationally representative sample of U.S. adults estimates that about 112,000 deaths are associated with obesity each year in the United States.’"

June 2, 2005 — CDC Director Julie Gerberding hosts a press conference aimed at "clearing the confusion" about the CDC’s role in addressing overweight and obesity. Saying she is "very sorry for the confusion that these scientific discussions have had," Gerberding emphasizes that "It is not OK to be overweight." Gerberding also insisted: "We don’t want people to artificially hide controversies. We want to get them out in the open." Her commitment to being "out in the open" comes only a few days after internal CDC documents reveal that much of the internal debate over the validity of the CDC’s original study was ignored by the authors. Gerberding was one of these authors.