Philip James and Neville Rigby say that obesity needs urgent action, while Paul Campos thinks we have much bigger worries on our plate

Recently, I published a brief opinion piece in which I criticised those of my fellow Americans who drive gigantic automobiles with "Support Our Troops" bumper stickers affixed to them. I suggested that consuming less gasoline might be more supportive than engaging in hypocritical jingoistic posturing.

This was not exactly a novel suggestion, so I was taken aback by the passionate response the piece elicited. To date, I have received more than 1,000 emails from around the world. Perhaps two thirds of these messages have agreed with the column's thesis; but the dissenters have made up for their minority status with some astonishing outbursts of verbal abuse.

All this brings to mind an argument I made earlier this year in my book The Obesity Myth , concerning why Americans seem so obsessed with the supposed dangers of weighing even a little more than average. I speculated that one way of understanding America's obsession with "obesity" is as a symptom of a deeper fear that we are threatening to consume the entire planet.

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For upper-class Americans in particular, it's easier to deal with anxiety about excessive consumption by obsessing about our weight rather than confronting more serious threats to our social and political health.

Upper-class Americans are much thinner than our working class and poor brethren, and we consume much more. We may drive grotesque SUVs that pour untold tons of pollutants into the atmosphere; we may consume a vastly disproportionate share of the world's scarce resources; we may support a foreign policy that consists of throwing America's military weight around without regard to objections from our allies - but at least we don't indulge in super-sizing our meals at McDonald's, or similar »å¨¦³¦±ô²¹²õ²õ¨¦ venues.

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Understanding the current hysteria over the supposed "obesity epidemic" as a kind of moral panic, driven by social anxieties that have little or nothing to do with the health risks associated with fat, helps explain the otherwise puzzling irrationality that marks our policies toward weight and health.

Consider the following facts, all of which are documented at length in my book, and many of which even the most fanatical anti-fat warriors don't bother to dispute: First, except at statistical extremes, the association between weight and health is weak. In particular, the so-called "overweight" category, containing those who have a body mass index of between 25 and 30 (for an average-height woman, this is between 66 and 79kgs), is completely phony, with no statistical support from medical science. So-called "overweight" people do not have shorter life expectancies or worse overall health than so-called "ideal-weight" people.

Second, even at weight levels that feature an association between higher weight and higher health risk, the extent to which higher weight causes this increased risk is very poorly established. Because "overweight" and "obese" people are also far more likely than average to face many well-established health risks - most notably poverty, sub-standard healthcare and poor nutrition, higher levels of stress, and various forms of discrimination - it is extremely difficult to establish how much, if any, of the weak correlation between "obesity" and health causes poor health, or is merely a marker for these and other risk factors.

Third, attempts to turn fat people into thin people almost always fail. One consequence of this is that there is very little evidence that weight loss in itself provides health benefits, while there is a great deal of evidence that losing weight and regaining it again (the outcome of almost all weight loss attempts) is harmful to health. It may well be that much or all of the health risk associated with "obesity" is actually a product of the perverse cures prescribed for an imaginary disease. On the other hand, getting sedentary people of all shapes and sizes to become more active is extremely beneficial to their health - and this remains true whether or not increased activity leads to any weight loss. Indeed, activity levels are far better predictors of health than body mass.

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Little of this, I repeat, is even particularly controversial. Consider then the sheer irrationality of the public health policies now being advocated across the world in regard to weight. These policies are based on the assumption that fat people could be thin if they wanted to be, and that the best way to create this desire is to publicise the advantages of thinness over fatness: something that Western culture has, on this view, failed to do. This is about as plausible as arguing that poor people are poor because our culture has failed to emphasise the advantages of wealth over poverty.

In other words, it's an insane theory, that would cause any person of normal intelligence to burst out laughing if it were stated straightforwardly, which is why it so rarely is.

Here are some questions that ought to be posed to our public health authorities whenever they issue a fresh wave of alarmist nonsense about how we are supposedly eating ourselves to death. Why does the overall health of people in developed nations continue to improve so markedly, despite the complete failure of the war on fat? How many people would still be "overweight" even if everyone had ideal health habits? Is there any evidence that shaming heavier people about their weight produces thinness? And by the way, doctor, if obsessing about the purported evils of fatness is supposed to make people thin, how do you explain your own body? (A majority of the American public health officials leading the war on fat are overweight by their own definition, often markedly so.) Over the past 15 years, the median weight of Americans has increased by about 3.6kg. Meanwhile, the most profitable segment of the American car market is made up of vehicles that weigh 1,360kg more than the most popular automobiles of the 1980s. That's our real "obesity epidemic".

Paul Campos is professor of law at the University of Colorado. His book, The Obesity Myth , is published by Gotham Books, ?13.08.

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