I never thought I'd see the day when Stanton Glantz and I would be happy about the same thing. But apparently the anti-smoking fanatic shares my glee at the CDC's embarrassing admission that it miscalculated the number of deaths attributable to obesity. To be more precise, the 400,000 figure was supposed to reflect all deaths associated with "poor diet and physical inactivity," not just excessive weight per se, leaving open to debate the relative contributions of fitness vs. fatness. But it was widely cited and accepted as an estimate of annual mortality from extra pounds.
Now the CDC says its researchers made a calculation error and will offer a substantially lower estimate in an upcoming issue of JAMA, where the original study was published last March. But as The New York Times (belatedly) notes, it was apparent that something was screwy with the number even before the CDC fessed up:
[University of Chicago political scientist Eric] Oliver, for example, said obesity, like tobacco, had little effect on mortality in people over 65. So with two million deaths a year in the United States, 70 percent of which are among people over 65, virtually every younger person who dies would have to die from obesity. "The numbers simply don't add up," he said.
In the September American Journal of Public Health, another team of CDC researchers published a critique of the method their colleagues used to generate the 400,000 figure. "Most deaths occur among older adults," they noted. "Estimates of deaths attributable to obesity can vary widely depending on the assumptions about relative risks of mortality associated with obesity among the elderly. Thus, it may be difficult to estimate deaths attributable to obesity with adequate accuracy and precision."
Glantz says the overestimation was due to "a very, very fundamental mistake that was made in the paper, which they have done nothing to address….This is not some esoteric little detail over which there is huge uncertainty."
Accuracy and precision are not exactly Glantz's forte, of course. If they were, he would not be so quick to embrace the claim that smoking bans cut heart attacks in half or the assertion that giving films in which characters smoke an R rating "would cut movie smoking's effect on kids in half, saving 50,000 lives a year in the U.S. alone."
No, what upset Glantz and his fellow anti-smoking activists (as the Times explains) was that obesity threatened to steal their "public health" thunder (and funding) by racking up a higher official death toll than smoking. Some might be dismayed at such squabbling among lifestyle dictators, but it's music to my ears.