Thursday, 30 June 2011

Study shows researchers ignore structural issues

[trigger warning]

The BBC has yet another badly-researched story about "obesity". I'll skip over the unmentioned assumption that "obesity" is such a bad thing it needs to be prevented at all costs, and move on to places where the article fails even in its own terms.

Firstly, the article talks about how average calorie intake has increased significantly in the US since the 1970s. Naturally, because "obesity" is a personal problem with no structural issues whatsoever, the article completely omits that since the 1970s the USA's problems with perverse food-production subsdisies, "food deserts" and so on, in many places it's difficult or impossible to get foods other than the energy-dense ones, and more expensive even when they are available.

This is also something that does not really generalise to the majority of the UK, or other Western European countries, despite the claim in the article that "many of the factors causing the obesity epidemic there are mirrored in the UK".

The recommendations of the researchers - police what people individually eat, rather than making it easier for them to get nutritious food cheaply - are equally predictable.

Secondly, the article in a box-out includes a note that:

The recommended daily calorie intake is 2,000 for women, and 2,500 for men (NHS Choices)

If we assume that there are roughly equal numbers of men and women, and gender is the only factor that affects energy needs, metabolic rates, digestion efficiency, and so on - but does so with 100% predictive power (which is ridiculous, but is what the recommendation needs to be assumed) then that gives an average recommendation of 2,250 calories daily for each person.

Compare that with the figures from the article on US average - the article doesn't specify if it's mean or median - calorie intake:

  • 1977-8: 1,803 calories
  • 1994ish (implied): 2,145 calories
  • 2003-6: 2,374 calories

So, comparing with the "recommended" average, we can see that it's only in the last decade or so that US residents have stopped being (on average) underfed.

The average hides a lot of rich/poor disparity, of course, and a lot of people in the US are still malnourished - my point is that even in terms of pretending these averages mean anything at all, the conclusion isn't the one that the rest of the article implies.

Of course, this is fairly typical of "anti-obesity" research and campaigning: set an unjustified target for calorie intake - and then claim it's bad when people get anywhere near it. "Pro-malnutrition" might be a better term for them: perhaps if they didn't have the privilege not to remember the effects of widespread malnutrition themselves, they'd think more carefully about what they were saying.