Resident Fellow  David Frum

Last week, the U.S. Centers for Disease Control released some rare good news in the struggle against obesity: For the first time in a generation, things are not getting worse.

One-third of all American men--and more than one-third of American women--are obese. Not just a little large, but seriously fat.

That's more than twice as many as in 1980. Over the past quarter-century, fatness has emerged as America's number one public-health problem--and not just America's. People are getting fatter throughout the developed world, including Canada. About one-quarter of all Canadians now bust the scales, as do one-quarter of all British people, more than one-quarter of Australians and 15% of Germans. Only the Japanese and Koreans seem exempt from this problem, at least so far.

Some might be tempted to attribute this fat explosion to the ageing of the population: As more of us become middle-aged, more of us are starting to carry around a few extra pounds. But obesity is growing as fast among children and teenagers as among adults.

Nor is obesity the same thing as being casually overweight. Health experts define obesity as a body-mass index of more than 30. To put that more visually, a woman standing 5' 6" would be considered obese if she weighed more than 186 pounds.

The health consequences of obesity are huge. The obese are more likely to suffer accidents and injury, to absent themselves from work, and to suffer depression and other mental illnesses. The CDC estimates the phenomenon is responsible for almost $100 billion in extra health-care spending per year, about one U.S. health dollar in 10.

Obesity harms the economy in other, unexpected ways as well: In 2000, U.S. airlines spent $275 million more on jet fuel than they would have had passengers weighed the same as they did in 1990. (Environmentalists will note that the airlines also emitted an extra 3.8 million tons of carbon dioxide as a result of transporting this extra human freight.)

Obesity may explain the growing gap between U.S. life expectancies and those elsewhere in the advanced world. In 1990, Americans lived almost half a year longer than the advanced-world average. By 2003, they had fallen more than half a year behind.

Never mind the proverbially healthy Swede: The average American now lives less long than the average Greek, Portuguese or Spaniard. Despite the climate, the booze and the bad roads, even the Irish now live longer than the Americans.

Nor should Canadians be complacent: While the advanced world as a whole has added three years to average lifespans since 1990, Canadians have added only two.

Why is this happening? Why so much worse in the U.S. than in the other English-speaking countries, and so much worse in the English-speaking countries than elsewhere in the developed world?

I hear you say: "People are eating too much!" Well yes, that's certainly the beginning of the answer. But only the beginning.

Food is cheaper relative to income in the United States than in any other country. Cities are less walkable; gasoline more affordable. Americans work longer hours than other English-speakers, who in turn work longer hours than Europeans, creating greater demand for prepared foods.

But above all, there is the problem of social attitudes. As people get fatter, they redefine what it means to be normal. Nobody wants to cause hurt feelings. Yet important new research finds that by accepting obesity, we are almost certainly aggravating it.

According to a major study published in the New England Journal of Medicine this summer, if even one of your friends becomes obese, your own odds of becoming obese rise by 57%. The impact of a friend's weight gain is much greater than that of a sibling or a spouse--and it holds true whether your friend lives around the corner or a five-hour drive away. The more intimate the friend, the greater the effect.

In that sense, obesity is contagious--and the battle against obesity has to begin by fighting the contagion.

Acknowledge the problem. Let schools and public health authorities speak explicitly about what constitutes healthy weight. Stop fretting about the hugely exaggerated problem of anorexia--and instead candidly tell young people that the "eating disorder" that most threatens them is eating too much, not too little.

Perhaps what is needed above all is a crusading leader, somebody who will make obesity a cause like drunk driving and anti-smoking.

And as it happens, we have the very guy: Republican presidential candidate Mike Huckabee, a former Arkansas governor who lost--and kept off--100 pounds. Huckabee has moved from nowhere in the polls to the probable Republican vice-presidential nominee on the strength of his wit and charm. Now he needs a cause. Why not this?

David Frum is a resident fellow at AEI.