A Battle of Ideas Independent blog calling into question the idea that obesity really costs society a fortune and pointing out that it is intolerance, not obesity, that is the really unhealthy trend.

‘You’re right. It’s not a disease, it’s a disgrace.’ That’s what former Militant council leader, turned permatanned gobshite, Derek Hatton told me on the BBC’s Sunday Morning Live as we discussed whether it was irresponsible to be fat. Hatton thought that fat people should be taxed. After all, he said, unlike drinkers and smokers they contribute nothing to the healthcare costs they impose upon society. He’s not alone. A few years ago, Giles Coren made a TV programme called Tax the Fat.

Does obesity really cost society a fortune? Not according to a study in the journal PLoS Medicine in 2008: ‘Although effective obesity prevention leads to a decrease in costs of obesity-related diseases, this decrease is offset by cost increases due to diseases unrelated to obesity in life-years gained. Obesity prevention may be an important and cost-effective way of improving public health, but it is not a cure for increasing health expenditures.’ In other words, making fat people slim would, at best, allow them to live longer only to suffer diseases not related to their obesity. The net effect would be to increase NHS expenditure.

Even if there were costs attached to obesity, it is not the case that those who eat so-called junk food contribute nothing in taxes. On the contrary, while fruit, vegetables, meat and other basic ingredients do not attract VAT in the UK, snacks, hot takeaway foods, sugary fizzy drinks and confectionery all get hit by 20 per cent VAT. My back-of-a-crisp-packet calculations suggest that’s worth about £4 billion to the Treasury every year. (I tried asking HMRC for an official figure, but they don’t keep those statistics, apparently.) While a ‘fat tax’ of one kind or another has been introduced in a number of European countries – most recently in Denmark – British shoppers have effectively been paying such a tax for years thanks to differential VAT rates.

The regular calls for a fat tax – whether on the ‘wrong’ foods or on fat people themselves – are symptomatic of two regressive trends in society. The first is the view that experts know best, that these latter-day sages can come to an impartial view based on The Science, then guide government about the appropriate policy action. The new, evidence-based policy usually involves some kind of manipulation of our individual behaviour from gentle ‘nudges’ and increasing taxes through to criminalisation, as in the case of the smoking ban.

But this is not evidence-based policy, but policy-based evidence, with preconceived ideas being pushed through in the name of science at a time when those at the top of society have lost the ability to convince the electorate on the basis of a moral or political argument. This style of policymaking rarely solves social problems, but it does distort both politics and science.

The second worrying trend is the sheer intolerance towards obese people. Being very overweight has always attracted a certain amount of moral opprobrium. But Hatton’s outlook reflects a sea-change. Once, the NHS reflected a progressive outlook that disease was a misfortune that could strike any of us at any time and that the best thing to do was to share that burden across society. Now it’s every man and woman for themselves. In the worldview of Hatton and Coren, some morally weak individuals are costing them money and must be punished.

Ironically, this flows from a left-wing view of disease as having social causes. In the late Seventies, left-wingers correctly saw that some ill-health was the result of poverty, poor housing, polluted air, and so on rather than infection or bad luck. Unfortunately, this has morphed into the idea that disease is caused by individual behaviour – and so health professionals have taken to camping out in our private lives, demanding we stop smoking, drinking and eating the wrong things. Every naughty little pleasure must now be sacrificed to the god of longevity. If we don’t play ball, this intolerance suggests we should lose our right to treatment.

The disease of intolerance is likely to have a far more detrimental effect on society than obesity ever could.

Fat tax: Does obesity really cost society a fortune?, Independent blogs