Big Reasons for Fat Skepticism

A version of this article appeared on, December 2, 2004.

The Centers for Disease Control announced recently that the often-mentioned figure of 400,000 American deaths each year due to obesity is based on a study that’s plagued by methodological errors. The CDC estimates that the number may be off by 20 percent, but longtime critics of the figure say it may be closer to four times the number of early deaths attributable to obesity.

The CDC’s announcement represents a tidy anecdote for what’s wrong with the fat debate. The problem, put simply, is that hysteria sells. It sells research to grant writers, it sells executive summaries to media outlets, and it sells newspapers to the public.

Anyone who took a close look at the 400,000 number could see obvious flaws in its computation. In the New York Times, the University of Chicago’s Dr. Eric Oliver pointed out that there are only 2 million deaths each year in the United States, total. Since obesity has little effect on the mortality rates of people over 65, and since 70 percent of annual deaths are among people over 65, in order for the 400,000 figure to be correct virtually every single death among people under 65 would have to have been caused by obesity.

There were other obvious problems. The Journal of the American Medical Association study that came up with the number was a meta-study, which examined other studies dating back as early as the 1940s and then extrapolated the data to today’s population. Obviously, several ailments that killed us 60 years ago are treatable and preventable today. Most remarkably, the study’s researchers admitted that their calculations “assume that all excess mortality in obese people is due to their adiposity.”

That’s an astounding concession. It means that every person in the study’s data who was obese and died early was assumed to have died because of obesity. There are thousands of things that could cause an obese person to die early — getting hit by a car or succumbing to cancer, for instance — that aren’t related to weight at all.

Despite these obvious flaws, the 400,000 figure was recited ad nauseum by government officials, nutrition activists, and the media. Researchers such as the University of Virginia’s Glen Gaesser and Dr. Katherine Flegal had been criticizing the figure since it was published, yet they were rarely consulted or quoted in press accounts.

A Lexis search finds over 1,500 mentions of “obesity” and “400,000” in the last two years. And that does not include mentions of “obesity will soon overtake smoking as America’s number-one killer,” a statement widely perpetuated in the obesity debate that was also based on those alleged 400,000 deaths.

Dig a little more into America’s health statistics and you’ll find that despite our expanding waistlines, we’ve never been healthier. Heart disease, stroke, and cardiovascular disease are all down dramatically in the last 20 years. Mortality rates in nine of the ten types of cancer most associated with obesity have dropped in the last 15 years. Overall cancer rates and deaths from cancer have dropped every year for the last ten years.

We’re living longer, too. In fact, while black men and black women have seen greater increases in obesity rates than their white counterparts over the last 15 years, they’ve also seen greater increases in life expectancy. The only ailment that is more common in the last 20 years is diabetes, and that can be at least partly attributed to an aging population or changes in the definition and collection methods of diabetes statistics.

If all the obesity hype is true, we should at least be seeing the front end of this pending health care disaster by now. It simply isn’t happening.

The troubling thing about the 400,000 fiasco is the way nutrition activists and politicians relied on such a flimsy number to call for drastic new laws and regulations, and that the media reported it with barely an ounce of skepticism.

Radley Balko is a policy analyst for the Cato Institute.