Tuesday, January 30, 2007

Child obesity

Is the next generation of Brits facing an epidemic of ill-health?

Panic: The UK House of Commons Committee of Public Accounts has published a new report lambasting the government for failing to tackle child obesity. The report notes that `obesity is a serious health condition', `a causal factor in a number of chronic diseases and conditions', and that `overall, it reduces life expectancy by an average of nine years'. According to the report, `there has been a steady rise in the number of children aged 2 to 10 who are obese - from 9.9 per cent in 1995 to 13.9 per cent in 2004.'

Don't panic: If the committee wishes to attack the government, and demand ever-greater intervention against parents, schools and companies, it had better get its facts straight. Obesity is not a serious health condition. It is a category of body morphology. The definition employed by the committee, the standard one in health circles, is that someone is `obese' if they have a body mass index (BMI) above 30; essentially, if the ratio of their weight to height is above a certain level. Aside from the fact that this ratio can just as easily describe excess muscle as excess fat, being fat does not necessarily imply ill-health. The majority of fat people are pretty healthy. In fact, it is those who, under today's abitrary categories, would be defined as `overweight' or moderately obese (with a BMI between 25 and 32) who seem to have the best life expectancy.

We do not know to what extent, if at all, obesity is a causal factor in chronic disease. We do know that obesity - particularly morbid obesity - is associated with increased risks of heart disease and type-2 diabetes, for example, but causation is a different matter. Given that fat people who are also fit seem to have very similar health profiles to thin but sedentary people, it may well be that lack of exercise not fatty tissue is the most important factor. In any event, untangling all the potential confounding factors makes the simple `obesity=disease/death' equation far too simplistic.

Specifically, the figure given for years of life lost is wrong. It appears to be repeating a statistic from a National Audit Office (NAO) report in 2001. However, what that report actually says is: `On average, each person whose death could be attributed to obesity lost nine years of life.' While this kind of attribution is fraught with problems, it is also very different from the statement in the latest report. The NAO report said six per cent of deaths were due to obesity - suggesting that most obese people die because of some other factor. Therefore, simple maths suggests the average number of years lost due to obesity is substantially lower than the nine years suggested by the new report.

As for child obesity, there is much dispute about what is an appropriate measure - BMI, for example, is even less relevant in children than in adults. But, according to the Health Survey for England in 2002: `About one in 20 boys (5.5 per cent) and about one in 15 girls (7.2 per cent) aged 2 to 15 were obese in 2002, according to the international classification.' While children have got a bit fatter in recent years, average weights for children have changed little.

We are facing an epidemic, it's true: an epidemic of regulation, intervention and fear-mongering. And it will all be based on reports like this one from the Committee of Public Accounts. While the motivations of these politicians may be sincere, their role in the obesity panic is likely only to make us more unhealthily obsessed with food and weight.


A diet of misinformation

John Luik, co-author of Diet Nation, tells Rob Lyons that the obesity panic is being fattened by savvy interest groups and junk science

`More than any other government, the UK government has bought into it. The UK leads the world in bad obesity policy.' I'm sitting in the offices of the Advertising Association discussing the obesity panic with John Luik, co-author of Diet Nation: Exposing the Obesity Crusade. Luik is a genial American policy analyst who's gunning for the `relatively small group of people around the world who have decided, manufactured, this as a problem, and who have sold it to governments.'

`If we had gotten paid by the advertising industry to write this book - which we didn't - people would say, "You guys are on the take". But you can have people on the other side who get hundreds of thousands of pounds from those who have a deliberate interest in making people think they're fat, and no-one thinks that is a question of corruption.'

In Diet Nation, Luik and his co-authors, Patrick Basham and Gio Gori, show that the fear of expanding waistlines is nothing new. But they argue that the modern hysteria about getting fat has little to do with real dangers to our health, or that of our children; rather it has become the obsession of an unholy alliance of sophisticated lobby groups and junk science.

This is perfectly illustrated by a report published by the House of Commons Committee of Public Accounts this week, which leaps from making plainly untrue statements about the problem of obesity to berating the government for not doing enough to address it, by clamping down on the food industry, for example, or frightening parents and stigmatising children.

Fretting over our waistlines has a long history. There was already medical discussion about the problem of obesity in the late nineteenth century, but as a `product rather than a cause' of the prejudice against excess weight. Within a few years, this issue started impacting on popular culture. In 1907 a popular American play called Nobody Likes a Fat Man was staged, and in 1913 Edith Wharton described one of her characters fretting about being anything more than `perpendicular'. As the authors of Diet Nation note, in one respect `the century-long European and American preoccupation with thinness and the rejection of fat is very much a social construct in which obesity is increasingly associated with the morally unacceptable' (p33).

The first obesity crusade took off in the Fifties, and was particularly inspired by the work of Louis Dublin, a biologist working for the Metropolitan Life Insurance Company in the US. He was a man on a mission. He wrote hundreds of articles on the subject and produced just the kind of research that is the mainstay of obesity discussions today: he rather dubiously compared the weight of individuals (often self-reported) with mortality many years later. There were many obvious limitations, especially the fact that the subjects were self-selected (insurance buyers were not typical of the population then), and that their weight was not regularly measured over the period of study; in fact, it was often not measured independently at all. And yet, Dublin tried to persuade America using this shaky data that not only was being morbidly obese bad for your health, but even levels of weight 10 per cent above his `ideal' could shorten your life.

While much of the medical profession supported Dublin, others were puzzled to find his results difficult to replicate. Anyway, his worst fears were not realised, as Diet Nation notes: `As the 1960s and 70s came and went, Americans did not lose significant amounts of weight, though they dieted continuously. They enjoyed better health, while the prevalence of most major diseases declined and longevity increased.' (p42)

For Luik et al, while the modern obesity crusade - which began in earnest in the 1990s - still has a moralising tone to it, the message coming from the crusaders emphasises another message just as much: `obesity is no longer a moral failing of bad fat people, but a sickness, acquired in large measure from a "toxic food environment", that requires medical treatment' (p34). It is true that contemporary campaigners against obesity talk about `evil corporations' as much as they do feckless individuals. So, much of the debate increasingly focuses on processed food (like the infamous Turkey Twizzler), fast-food restaurants like McDonald's, agonised debates about labelling, and bans on adverts.

However, it would be wrong to understate the powerful moralistic streak in discussions of obesity and food. In the focus on junk-food restaurants, for example, there is often a barely concealed contempt for the largely working-class people who eat there, who are presumed to be lazy, unthinking and not sufficiently concerned with healthy cooking and physical exercise. They are seen as `junk' people. At a time when it is unfashionable to pass strictly moral judgements on people's lifestyles, the lower orders tend to be maligned through the coded issue of food and health.

The crusaders have maintained a clear and oft-repeated message, according to Luik and his co-authors: `Overweight/obesity equals death; weight loss is possible and necessary; the sources of the problem are to be found in corporate misbehaviour, not individual gluttony or sloth; and personal responsibility is insufficient, as significant governmental action is required.' (p43) While the authors concede that many campaigners may be sincere, `the existence of an obesity epidemic offers enormous commercial, financial and power-maximising opportunities for. the medical profession, academic researchers, the public health community, the government health bureaucracy, the pharmaceutical industry, the fitness industry and the weight-loss industry' (p44).

From this point of view, it's the persistence, brilliance and deviousness of the campaigners, backed by the attitude-distorting presence of very sizeable amounts of money and influence, that have driven the current panic. There is no doubt much truth in this. Often, it is the same relatively small band of experts who conduct research, get paid to be consultants for industry, sit on the boards of specialist journals, and are asked to give evidence to, or advise, governments on public health policy.

The mechanics of how power and influence are grabbed are intriguing, especially when the players involved occasionally make a hash of it. Consider the report of the House of Commons Health Committee published in May 2004, which focused on the effect of obesity on children. The report made a huge splash with the case of a three-year-old girl who had died `from heart failure where obesity was a contributory factor'. The doctor giving evidence on the case described children on her own ward as `choking on their own fat'. However, as spiked revealed at the time, this was not a case of parents negligently feeding a child to death; rather the little girl suffered from a rare genetic disorder (see Choking on the facts, by Brendan O'Neill).

Then there is the case of the US report from the Centers for Disease Control and Prevention (CDC), published in the Journal of the American Medical Association in 2004, which proclaimed that obesity was causing 400,000 deaths a year. This immediately sparked calls for massive government intervention. However, the authors of Diet Nation note how the report was prepared, not by the CDC's top experts on the subject, but by the CDC's director and other researchers attached to her office. After what appears to have been considerable internal criticism of the report, another group of CDC researchers reviewed it, and their review eventually found its way into the public domain under a Freedom of Information request. This second report suggested that a more accurate figure for excess obesity deaths was about 25,000 - 94 per cent lower than the original estimate. Strikingly, the original report was produced under pressure to `get the right result' because a range of groups had an interest in reaching the highest possible figure.

Such methods of securing influence may be increasingly common; yet there is something slightly unsatisfactory in using this as an explanation for the obesity panic. Are governments and the public simply being suckered? Or have there been social and political changes that have left individuals more open to being spooked about their health, and politicians more enthusiastic about interfering in areas of our lives that were previously off-limits? These questions aren't really answered in Diet Nation.

Too often the debate about obesity ends up in a mud-slinging contest over which side is the more corrupted. This provides little illumination into the facts of the matter, and it feeds the cynical outlook that suggests anyone's position can be evaluated by those who have paid to support it. On that basis, Luik and his co-authors could easily be pigeonholed as `free market libertarians' or something similar, as a means of dismissing them. But they clearly have a great deal more to say about obesity than the question of who-paid-who.

The chapter on the science of obesity will surprise many. Luik tells me about a presentation he gave recently at the offices of a major international bank in London. Having discovered that the audience's main concern was with the possibility of dying young from being overweight, he told them: `You'll probably find this astonishing but the people who are most long-lived in these studies are people who I would call "pleasantly plump" or overweight. In fact, even moderately obese live longer those who are the "norm".' The reaction he received shows how deeply imbued the panic has become: `People look at you like you're someone who has two heads.'

Yet Diet Nation claims that in the arbitrary weight categories set by the health authorities and their supporters today, those who are `overweight' - officially `ill', according to today's standards - live longer than those whose weight is apparently `ideal'. This would seem to highlight the ridiculous nature of the Body Mass Index and weight charts that are so popular now. Even those who are morbidly obese are likely to be able to reduce many of the risks associated with their weight by simply taking moderate exercise, even if they fail to lose any weight at all. And the usual prescription for losing weight - dieting - is, by any sensible medical standards, a failure. Weight loss is very difficult to sustain; around 96 per cent of dieters are at least as heavy as their starting weight five years later.

The myth of dieting is a subject that Luik and his colleagues are keen to return to in another book. Having looked at 28 separate papers on the long-term effects of dieting, Luik tells me that 24 show no benefit to losing weight. Even where a benefit is found, it's small. `Here's an example. One study concluded that if you were successful in losing 50 pounds and keeping it off for the rest of your life, you would have a longevity increase in the order of 11 hours.'

Another area where the science is pretty much the opposite of what we've been led to believe is the effect of advertising on children - a topical issue in the UK since Ofcom's recent decision to ban the advertising of `unhealthy' foods during children's TV programmes. Luik sums up the evidence pithily: `We're saying that kids that can operate computers from the time they're three, and have immense media literacy, are so unaware of advertising up to the age of 16 that they can be convinced to buy a packet of crisps by seeing an advertisement, or that a cartoon character is going to convince them to buy a breakfast cereal.' All of which explains why I'm meeting Luik at the offices of Advertising Association: he's just given a talk to the association about why they must tackle the dubious claims made about obesity and the draconian measures being proposed to deal with it.

This isn't just a concern for advertisers, though. The lessons of the campaign against tobacco illustrate that a tactical move to attack industry will sooner or later lead to further attacks on our individual freedoms. Having convinced the world that cigarettes were an evil brought down upon us from on high by Big Tobacco, smokers now find themselves banned in public places; some agencies now ban smokers from lighting up in their own homes if they are being visited by health or social workers; and doctors are increasingly feeling free to refuse treatment to those who won't give up. In turn, the obesity panic is already leading to parents being instructed about how they should feed their children, while hospitals are also turning away the obese.

For the moment, Big Food or the advertising industry might be the fall guys; but it's in all of our interests to oppose the stringent measures being implemented on the basis of this junk panic. Diet Nation has its flaws, but it is an important contribution to our understanding, cutting through the flabby debate that has taken place so far.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.

The use of extreme quintiles (fifths) to examine effects is in fact so common as to be almost universal but suggests to the experienced observer that the differences between the mean scores of the experimental and control groups were not statistically significant -- thus making the article concerned little more than an exercise in deception


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