Inflating the obesity scare
- Ivo Vegter
- 09 Jul 2012 11:27 (South Africa)
“Rio+20: The world is getting too heavy finds new league table of fattest countries on Earth,” ran the long run-on headline over an article by Louise Gray, the Telegraph’s environment correspondent.
“The human population is getting too heavy for the Earth, according to the first study to calculate the impact our growing waistlines are having on the environment.”
The piece was published in advance of the largest-ever United Nations environment conference, dubbed “Rio+20”, which afterwards (happily) would be described as a “failure of epic proportions”, by Greenpeace, Time magazine, the Guardian and CNN.
Accompanying the Telegraph piece is a handy infographic under the byline of the delightfully named Conrad Quilty-Harper, based on a study entitled “Weight of Nations: An Estimation of Adult Human Biomass”, conducted by environmentalist Susan Walpole and her friends at the London School of Hygiene and Tropical Medicine.
As it turns out, my weight is a little above average by global standards. Anyone who has met me will no doubt find the notion that my lanky, skinny body is in any way normal, or average, preposterous.
The problem, of course, is that “weight” does not equal “fat”. (For that matter, it doesn’t equal “mass” either, which is something else you’d expect environmental correspondents to know.)
Many factors play a role in whether you weigh too much or too little. I, for example, am of Dutch stock. The Netherlands ranked 70th on the world “fat” index, at 68.74kg, while Cambodia came in 161st place, at 55.74kg. However, as measured by average male height, these two countries are respectively the tallest and shortest in the world. Adjusting for height, as the popular body mass index (BMI) does, makes the Dutch only 9% heavier than Cambodians, instead of 23% as the Telegraph’s cute graphic would have us believe. If you take my height into account, I am in fact somewhat underweight. If you’re thinner than I am, you’re probably either ill or starving. If you’re neither, but you still weigh less, I’ll bet you’re either a woman or you’re shorter.
There’s a reason Bangladesh makes the Telegraph infographic as the least “fat” country on earth, with an average weight of less than 50kg. Its people are not very tall and, more importantly, it is very poor. About 40% of the Bangladeshi population live below the World Bank poverty line of $1.25 per day. This is nothing to celebrate.
Not that BMI, which at least adjusts for height, is a particularly useful indicator either. Its formula, body mass (kg) divided by the square of body height (m), takes no account of muscle mass, bone structure, gender, age or climate, for example. Westerners are considered overweight with a BMI of 25, while for Asians the threshold is 23, but these are broad generalisations.
Sportspeople often measure as overweight on the BMI scale. The relatively short but compact rugby player Gio Aplon, at 78kg, is considered overweight for someone with a height of 1.75m. Even the towering Victor Matfield is well overweight. Standing 2m tall, his normal weight range would be between 74kg and 99.6kg, but he tips the scales at 110kg. I wouldn’t call either of them fat, if I were you..
You see, even the BMI was never designed as an individual diagnostic measure, despite the tendency of the media, dieticians and even doctors (who ought to know better) to use it as such. The Telegraph invites readers to see how their mass compares to that of “the average adult”, but even the more sophisticated BMI measure would have made it a laughably simplistic comparison.
BMI was designed as an average population metric. Its classification brackets have changed over time and from one country to the next, making it a tricky measure to use even for large-scale comparative studies. But the Telegraph story doesn’t even get that far in its uncritical acceptance of the latest environmentalist scare. Its entire premise is based on the over-simplification that mass somehow indicates how fat people are. It makes a contrived argument about how much more rich countries consume than poor countries.
“If all countries had the same average body mass as the USA the total human biomass would increase by 58 million tonnes – this is the equivalent of an additional 935 million people,” Gray writes, without bothering to attribute this “fact” to the study authors.
Other publications, like the BBC and the Global Mail take a similar line. The latter recalls environmental luminaries like Thomas Malthus, Paul Ehrlich and Jeffrey Sachs, who have all at one time or another wrung their neurotic hands about overpopulation. The author, Ellen Fanning, doesn’t think it worth noting that they were all spectacularly wrong. For example, Ehrlich solemnly promised in his 1968 book The Population Bomb that hundreds of millions of people would starve in the 1970s and 1980s, as population outstripped humanity’s ability to feed itself. He advocated compulsory birth control as a solution. And the delusional prophet of doom is still at it.
The only person who doesn’t think Paul Ehrlich was ever wrong is Paul Ehrlich. This inconvenient truth about overpopulation didn’t cause Fanning to question the presumption that now overweight is going to get us instead. She quotes one of the report’s co-authors, a professor of epidemiology and public health, Ian Roberts: “For years the discussion around population has been about, you know, people in Africa having too many babies. It's actually more nuanced than that because people who are fat have a disproportionately large ecological footprint.”
What does that mean? That rich-world environmentalists, instead of blaming “people in Africa” for a resource crisis that never came, should invent even more absurd measures so they can blame themselves?
In the study’s defence, it does mention body mass index and tries to estimate the food energy that is needed to sustain those who really are overweight. At least that is relevant to its central thesis: “Our scenarios suggest that global trends of increasing body mass will have important resource implications and that, unchecked, increasing BMI could have the same implications for world energy requirements as an extra 473 million people. Tackling population fatness may be critical to world food security and ecological sustainability.”
Note how the “energy requirement” is only half as scary as the body mass equivalent that Gray chooses to quote. But how scary are they? Turns out the presumption of “unchecked” obesity trends is not as well supported as one might think. A Lancet study of the period 1980 to 2008 finds that, worldwide, BMI has increased by only half a point per decade. At least some of this will be due to better nutrition among the world’s poor, rather than more overweight rich people. In fact, an OECD Obesity Update published earlier in 2012 notes that, in many first-world countries, obesity rates among adults and children have stabilised. In a telling chart, the Organisation for Economic Co-operation and Development demonstrates how exaggerated its own 2005 predictions were. For the seven member countries documented, it found that past projections were often much worse than what actually happened.
Obesity is obviously a personal health problem for those afflicted by the condition. It may be a public health concern in countries with particularly high obesity rates like the US. However, it is not an escalating global crisis that is driving the planet’s environment to the brink. On the contrary, history shows that environmentalists’ fears about running out of resources have always been greatly exaggerated.
To make rational decisions about our lifestyles and health we need truth, not exaggeration. To make informed choices about public-policy interventions, we need science, not misleading propaganda.
According to Fanning’s version of the story, “Professor Roberts hopes this new report will ‘put fatness on the radar as an ecological concern’, linking the public health efforts to combat rising obesity rates in the developed world to the broader debate about sustainability.”
Right you are, prof. Nice to see such a frank admission that all this hyperbolic bloviating is a matter of politics, not science.
And who is paying for all this politicised “research”, scolding us for our supposed excesses? Could it be environmentalists who distrust progress and sneer at prosperity? Could it be governments that seek excuses to impose new taxes and regulations on their citizens? Thought so. DM