TCS Daily

They Don't Embarrass Easily

By John Luik - April 26, 2005 12:00 AM

A few years ago The New York Times ran a cartoon that showed two Washington DC policy experts having a conversation. "In Washington the search for truth is a creative process. First, you create a premise. Next you create a statistic to back it up. Then you create an audience by repeating it over and over again, until the media pick it up. That's when you know that you've done it."

"Done what?"

"Created a fact!"

Just add Atlanta -- the home of the Centers for Disease Control -- to Washington and you have a pretty good idea of how obesity science and policy are made these days. Despite the fact that the CDC has been caught out creating "statistics" to back up the "fact" of an obesity epidemic, it appears to be neither embarrassed nor remorseful. As the Associated Press reported:

"CDC Director Dr. Julie Gerberding said because of the uncertainty in calculating the health effects of being overweight, the CDC is not going to use the brand-new figure of 25,814 in its public awareness campaigns and is not going to scale back its fight against obesity."

So let's get this straight. When the CDC's numbers said that obesity was overtaking tobacco as the leading cause of death, allegedly killing 400,000 Americans a year, it was all right to use that 400,000 figure non-stop to scare us into losing weight. But when the real number turns out to be just short of 26,000 then the CDC is so worried about "uncertainty" that they aren't going to use the figure. Obviously, Dr. Gerberding did not get her doctorate in logic.

The reason, of course, that Dr. Gerberding does not want to use the supposed 25,814 deaths (remember, we're not even certain there are this many) from obesity as the basis for a new campaign in the war on fat is that, well, as things go, it just isn't terribly useful. Gerberding knows that it is pretty hard to talk about an epidemic if you've only got 25,000 victims, and without talk of an epidemic it's pretty difficult to get the media's attention, Washington's money and, most importantly, push through a host of coercive policy measures that tell Americans what they can and what they cannot eat.

But notice, the good doctor isn't going to let a few hundred thousand fewer deaths stop a good thing. Despite the lack of credible statistics, we just "know" that obesity is still killing millions of Americans -- even if we can't find where they live -- and there is no reason to "scale back" the fight against obesity. Now that's what makes the CDC and much of official Washington such scary places. Typically a good public policy process first finds clear evidence of a substantial problem and then goes about finding a policy solution. Evidence drives and shapes policy. But here we have policy "creating" evidence. Even though the supposed justification for intervening into the lives of millions of Americans is now defunct, the claim that fat causes early death is still made and the campaign against obesity still goes forward.

Of course, what Dr. Gerberding was too modest to tell the Associated Press is that the 25,814 figure is not destined to survive for long as it is just too inconvenient. Already someone, somewhere, has started the tedious but very necessary work of crunching some more acceptable number that will bolster the "fact" of obesity=premature death back into headline-grabbing territory. But just to make that enterprise as difficult as possible, here are a few non-Washington statistics from the last 50 years about the alleged dangers of being overweight and obese.

First, take the study that really started the "obesity epidemic", the 1999 JAMA published research "Annual Deaths Attributable to Obesity in the United States" which suggested that being overweight was responsible for about 300,000 deaths a year in the US. If you look at this data you find that individuals with BMI's of 25 -- overweight -- have a lower risk of dying prematurely than those with BMI's of 20 or normal weight. Again, those with BMI's of 20 have the same risk of premature death as those with a BMI of 30 -- obese.

Second, take another widely cited study, "Overweight, Obesity and Mortality from Cancer" (New England Journal of Medicine, 2003) which like the JAMA article generated huge headlines with its claim to provide a definitive account of the obesity-cancer relationship. The authors claimed that up to 90,000 cancer deaths a year could be avoided if every adult kept his or her BMI below 25. Yet the data actually shows something quite different. People with BMI's of 18.5-24.9 - normal -- had a cancer mortality rate of 4.5 deaths per 1000 study subjects while individuals with BMI's of 25-29.0 -- the overweight -- had a cancer mortality rate of 4.4 deaths per thousand -- actually lower. In other words, for the 100 millions plus Americans who are classified as overweight there was a negative correlation between being overweight and dying from cancer.

Nor are these findings flukes. Ancel Keys, the proponent of the cholesterol-heart disease theory, who over 25 years looked at fat and mortality rates in Japan, Greece, Italy, Yugoslavia, the Netherlands, Finland and the United States came to similar conclusions. Published as the Seven Country Study in 1980, Keys found the risk of premature mortality due to excessive weight increased only at the extremes of over and under weight. A recent study looking at a group of Europeans from his original data found men with BMI's of less than 18.5 -- that is thin men -- had almost twice the mortality rate of either normal or overweight men, even controlling for smoking. The study further found that being overweight -- a BMI of 25-29.9 -- had no effect on mortality and even those men who were obese still had lower death rates than the thin men.

A similar pattern was found in a 1996 US study that re-analyzed data from previous studies involving more than 600,000 subjects. The study found white males with BMI's in the normal range of 19-21 had the same mortality rate as those with BMI's of 29-31 -- overweight and obese. Again, for non-smoking white males, the lowest mortality rate was found with BMI's of 23-29, a range that includes the overweight.

Perhaps as we wait for the next set of statistics that purports to show us dying by the thousands from our fat we can console ourselves with the one genuine fact in this sorry mess which is that we have more to be worried about in junk science than in junk food.

The author is a health policy writer living in Canada.


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