The New Republic has a fantastic article attacking the obesity myth. Paul Campos, the author, calmly and methodically details the misuse and misinterpretation of epidemiological studies to show that, contrary to what's often reported, being overweight (particularly according to the deeply flawed Body Mass Index) is possibly healthy, and the most important predictor in any case is cardiovascular fitness -- weight is merely a crude stand-in. But mistaking correlation for causation when it comes to fat is but half the story. The hysteria's intensity owes much more to our cultural repulsion towards flab and the massive industry that has arisen to combat it:
Americans think being fat is disgusting. That psychological truth creates an enormous incentive to give our disgust a respectable motivation. In other words, being fat must be terrible for one's health, because if it isn't that means our increasing hatred of fat represents a social, psychological, and moral problem rather than a medical one.
The convergence of economic interest and psychological motivation helps ensure that, for example, when former Surgeon General Koop raised more than $2 million from diet-industry heavyweights Weight Watchers and Jenny Craig for his Shape Up America foundation, he remained largely immune to the charge that he was exploiting a national neurosis for financial gain. After all, "everyone knows" that fat is a major health risk, so why should we find it disturbing to discover such close links between prominent former public health officials and the dietary-pharmaceutical complex?
The issue isn't fat, but fitness. Problem is, though we all "know" a sedentary lifestyle and junk food diet are unhealthy, we spend our time combatting what we perceive as the aesthetic end point of such habits, not the root causes. And then, through diet pills, eating disorders, and neuroses, we try to slim down without shaping up.
So what should we do about fat in the United States? The short answer is: nothing. The longer answer is that we should refocus our attention from people's waistlines to their levels of activity. Americans have become far too sedentary. It sometimes seems that much of American life is organized around the principle that people should be able to go through an average day without ever actually using their legs. We do eat too much junk that isn't good for us because it's quick and cheap and easier than taking the time and money to prepare food that is both nutritious and satisfies our cravings.
A rational public health policy would emphasize that the keys to good health (at least those that anyone can do anything about--genetic factors remain far more important than anything else) are, in roughly descending order of importance: not to smoke, not to be an alcoholic or drug addict, not to be sedentary, and not to eat a diet packed with junk food. It's true that a more active populace that ate a healthier diet would be somewhat thinner, as would a nation that wasn't dieting obsessively. Even so, there is no reason why there shouldn't be millions of healthy, happy fat people in the United States, as there no doubt would be in a culture that maintained a rational attitude toward the fact that people will always come in all shapes and sizes, whether they live healthy lives or not. In the end, nothing could be easier than to win the war on fat: All we need to do is stop fighting it.
That bit about genetics isn't nearly so certain as Campos suggests, but his general gist is sound. America is an unhealthy society, and that has helped make us a fat one. But from a public health standpoint, the problems are too much time at a desk, too much processed food, too many hours at work, too little walking, and a host of other socio-cultural-political elements that incentivize poor habits, not our waistlines.