Author: John Luik
Article Published: 02/03/2004
About the only thing they are eating these days at the US Centers for Disease Control is crow. That’s because the Center has had to admit that its much hyped figure of 400,000 deaths per year from obesity is dead wrong. According to a story by Betsy McKay in the Wall Street Journal the Center has determined that “mathematical errors may have inflated the study’s death toll by about 80,000 fatalities, or 20% of the total deaths.”
Critics of the study argue that even that number is conservative, claiming that the true figure of obesity caused deaths is actually closer to 200,000. According to the Journal the study, which showed deaths from obesity overtaking those from tobacco, was criticized by insiders at the CDC for its assumptions, methodology and data sources even before publication. But in the rush to justify the growing war on fat these concerns were apparently pushed aside.
While the Center was quick to claim that the mistaken estimate of obesity related deaths was merely a “statistical error” and not an attempt to falsify the data, the more one looks at the way the report was compiled the more it raises substantial scientific and ethical worries about the entire war on fat. Much of that worry comes from the fact that even after being forced to admit that its obesity death toll was widely inaccurate, the CDC was still unwilling to admit that obesity was at best a phantom killer. As the co-author of the study and Director of CDC told the Journal “The bottom line is that obesity is a leading cause of death.” But is it?
The difficulty with the idea that obesity is a cause of death is that both the logic and the statistics of death and disease simply don’t support it. For instance, obesity itself is not a disease which means that if it has a role in mortality it can only do so through some real disease like heart disease, cancer or diabetes. But the problem here is that both heart disease and cancer are diseases with multiple risk factors, indeed hundreds of them. So it is impossible to know which risk factor led to each death and thus to know what role obesity might have played in any single death.
But there are other difficulties. If obesity is causing an epidemic of deaths than you should expect to find a sharp increase from deaths from things like heart disease, cancer and diabetes. But data shows that deaths from cardiovascular disease, coronary heart disease and many cancers have actually been declining not increasing over the last decade, even while deaths from obesity have allegedly been soaring. Even the question of diabetes mortality is complicated since it is not at all clear that blood sugar levels are in fact rising and the definition of diabetes was changed from a fasting blood sugar level of 140 to 126, which overnight created millions of new diabetics. Even the CDC’s own diabetes figures- if we can trust them - show that the incidence of Type 2 ( which accounts for 90% of diabetes) increased by only .04% over the last decade in which obesity rates have allegedly increased from 45-60%.
Then there is the little matter of how the elderly figure into the death by obesity equation. We know, for instance, that in the
And speaking of data, just where did the CDC turn for its numbers? According to the Center for Consumer Freedom it relied on the methodology of a David Allison from the
The biggest problem with the CDC’s numbers of course is that they contradict a vast literature on obesity, overweight and mortality that shows that being overweight or obese does NOT translate into an increased risk for mortality. For example, in an analysis of over 500,00 men and women done by the US National Center for Health Statistics, the lowest mortality was for those individuals with BMI’s between 23-29, in fact most of the “overweight” range. Nor was this simply a freak outcome. In the famous 1999 study in JAMA that claimed to find 300,000 US obesity-related deaths, the data showed that those with BMI’s of 20-ideal- run the same mortality risk as those with BMI’s of 30- the obese.
All of this suggests that this is not merely some storm in the statistical teacup but a major credibility issue for the entire war on fat. The only basis for the massive interventions into the nation’s stomachs being proposed by the government and the public health community is that we are all getting excessively fat and our fat is killing us. But between the doubts about the CDC numbers, the evidence that most of us gain about a pound a year (most of it during the holidays according to the New England Journal of Medicine) and the huge literature that fails to find a link between overweight and premature mortality, the rationale for the war on fact looks like it is dissolving under a weight of junk science.
John Luik, a health policy analyst, is co-author with Mike Waterson, of Advertising and Markets