Thursday, May 14, 2009

Does this kid look fat to you?

Dr John Ray asks the pertinent question here - when "will this totally unscientific mania ever fade?"
He reproduces an article from The Telegraph (see at the end of this post) that perfectly highlights the madness that wellness and healthy lifestyle programs are producing.
Let's be clear about this. These programs are often not based upon sound science.
They now form the basis for government advertising, both here and in Great Britain, that can only be described as a largely pointless waste of tax dollars that could have been spent productively elsewhere.
There is no credible evidence to support the claim that even if he were overweight he would be at greater risk of cancer later in life.
None at all. The high quality properly randomised double-blind trials have found no such linkage between diet, overweight and cancer.
The false claim that there is a link rests solely on a number of poor quality epidemiological studies with weak findings.
But the problem is that matters of health have been taken over by a collection of "moral puritans" and "moral entrepreneurs" who have been conducting a crusade against fat. I'm not saying that fat and diet is completely irrelevant to health, rather that this debate has become decoupled from the actual evidence and is not being driven by the evidence.
So it is interesting to see that The Australian and the Weekend Australian Magazine have now blown the lid on the fake childhood obesity epidemic here in Australia.

It’s easy to lie with statistics, graphs and scary marketing, and even to get people to believe the opposite of reality, such as in an epidemic of obese, unhealthy and sedentary children. As alarming claims are repeated and the most extreme examples are depicted as representative of the crisis, few people stop to question how a statistic is being defined.


With today’s new definition of “overweight” (children ≥95th percentile on new BMI growth curves, also called “obese” depending on the author), a mere 5 pounds makes the difference between a first grader being labeled as “normal” or “obese.” Even doctors are unable to recognize the children who meet the definition and few people understand what most “obese” and “overweight” children really look like. If they did, of course, they’d realize how incredible the claims of a crisis really are.

(It'll be worth your while following the embedded links in that quote.)
There are going to have to be some hard questions asked of health academics and government health agencies who have actively promoted this myth, even when any sober consideration of the evidence should have made it clear that there was something terribly wrong with it.
The crucial question here is how is it possible for bad ideas, poorly supported by hard evidence, to take over whole areas of science and public policy and become moral crusades, not carefully thought through and considered policy decisions?
For this I would yet again refer people back to the article by John Tierney, the science writer for The New York Times, entitled Diet and Fat: A Severe Case of Mistaken Consensus, and its notion of informational cascades.
Briefly, this is the process where the loudest voices and not the evidence take over a topic. These voices, because they seem authoritative and most of us don't have the time or the ability to do our own research, set what others think about an issue and everybody proceeds on that assumption.
Then this becomes entrenched as an orthodoxy and to speak against it carries the threat of being denounced as a "heretic."
This is what happened with our understanding of diet, fat and health.
The loud voices convinced other academics who didn't bother to look very deeply at the claims being made, and then the bureaucracy and politicians came on board, deciding that "something had to be done" and it was their responsibility to do it.
So it got to the point where other scientists would appear before Congressional committees in the US to try and explain why the concern about fat may not in fact be supported by good evidence, only to be ridiculed and derided as enemies of the public good.
And woe unto them if they had ever done any work of any kind for the food industry at any time. Then they were pilloried as the paid stooges of big business, putting the interests of money ahead of people's health and well being.
A kind of McCarthyism prevailed.
It is now dawning on some people that they were probably also right.
The Telegraph's article:

Posted via email from Garth's posterous

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