Day By Day

Tuesday, April 19, 2005

The Dangers of obesity have been overblown, so says the CDC and JAMA

Whoops, they did it again. The Center for Disease Control [CDC] has reversed itself on the dangers of obesity. AP 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 new analysis found that obesity — being extremely overweight — is indisputably lethal. But like several recent smaller studies, it found that people who are modestly overweight actually have a lower risk of death than those of normal weight. [empasis mine]

Biostatistician Mary Grace Kovar, a consultant for the University of Chicago's National Opinion Research Center in Washington, said "normal" may be set too low for today's population. Also, Americans classified as overweight are eating better, exercising more and managing their blood pressure better than they used to, she said.
A related study, also in Wednesday's JAMA, found that overweight Americans are healthier than ever, thanks to better maintenance of blood pressure and cholesterol levels. Diabetes is on the rise among people in all weight categories, however.

Flegal said the two studies raise questions about what definitions to use for obesity and "where to draw the line." Under current government standards, a BMI, or weight-to-height measurement, of 25 or higher is overweight; 30 and above is obese.

In recent years, the government has spent millions of dollars fighting obesity and publicizing the message that two out of three American adults are overweight or obese, and at higher risk for heart disease, arthritis and diabetes. [emphasis mine]

Once again the US government, basing their policy on the testimony of medical experts, has launched a major scare campaign aimed at changing public behavior. Now we find out that the experts are wrong. This is not the first time this has happened. Remember the anti-cholesterol campaign of a few years ago?

What will they do now? From past experience they will do an Emily Litella and just say "never mind." But real damage has been done. Because of government action the lives of hundreds of millions of people have been altered, new costs have been placed on health care, food, insurance, and a host of other activities and products.

About a quarter of a century ago Charles E. Lindblom and David K. Cohen published a wonderful little book, Usable Knowledge (New Haven, Conn.: Yale University Press, 1979), in which they argued that expert knowledge in science, and especially in the social and medical sciences, is constantly in flux and therefore has limited utility as a guide for social policy.

It is easy for scientists to quickly shift their opinion -- indeed they often do -- to account for new ideas or evidence, but governments cannot do the same. Once policies are set in place they develop institutional inertia and constituencies emerge. People's lives are permanently affected. Entire agencies are created. Long term costs are assumed. These are real consequences affecting real people in large numbers.

The total cost is not just the millions that the government spent on publicizing the policy -- it involves the tens and even hundreds of billions of dollars in costs and time imposed on people and businesses induced to alter their activities to conform with government policies. Think of the medical costs, the insurance costs, the food costs, etc. heaped on consumers. Think of the industries that were affected negatively by the government's crusade against certain food types. The costs of irresponsible policies are staggering.

And there is a higher cost involved. Every time the government undertakes one of these massive attempts to control the lives of citizens it is putting its credibility on the line. But time and again the government scare campaigns have proven to be ill-founded. And each time it happens the credibility of the government is undermined. This repeated and hugely publicized failure of policy has contributed significantly to the pervasive mistrust of government that characterizes our modern political culture.


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