Saturday, July 21, 2012
Conditional Chain of inferences with BMI and health:
There is a strong correlation with BMI and Health - > The Correlation is Causal -> Because of this we should and can make people thinner -> Thus by doing so we can improve their health
What happens when the first link in the chain is false? or even the second link, third or fourth? What if all of them are wrong, independently of each other? In an interview with Truth Driven Thinking ,Paul Campos, Author of The Obesity Myth, discusses(See the quotations below) the many fallacies of the conditional chain mentioned above.
"...if you look at the people who are classified as overweight in the United States at present, that is, people who have a body mass of between 25 and 29.9, which for an average height woman -- to give you a sense of that means, is about between 145 and 174 pounds, and for an average height man between about 175 and 200 pounds. If you look at people in that weight range, there is absolutely no correlation between their weight and increased health risk, quite the contrary. If anything, there is a slightly decreased health risk and a slightly higher life expectancy in the overweight range than in the so-called normal or ideal weight range as the government recommends."
"...people have this hypothesis in their head, and then any evidence which tends to correlate with the hypothesis gets empathized and remembered and all the evidence that doesn’t correlate just gets forgotten... I think what happens is that people get certain beliefs so deeply lodged in their head, for ideological and political and psychological and economic reasons, that they become literally incapable of considering that that idea might be false."
"...what you find in these studies over and over again is that you actually break down their data, is there is no dose response whatsoever. What that means in the medical jargon is, if you think that weight loss is significant as a causal factor, what would you expect to see then is that the people who would lose a lot of weight would get a great benefit, while the people who’d lose a little weight would get a small benefit, while the people who lose no weight wouldn't get any benefit, that’s dose response, right? In fact, there isn't any dose response; if you actually look at the statistics, there is no correlation whatsoever between the people who lose a lot of weight, the people who lose a little weight, and the people who lose no weight, they all get the same effects on the intervention."
"So clearly, what’s drivingthe beneficial health affects, it doesn’t have anything to do with weight, it has to do with the lifestyle changes, which in some cases, will produce weight loss, but in many cases will not."
" There is quite a bit of evidence that weight cycling -- that losing weight and then gaining it again is quite bad for you -- and since this is the outcome of the vast majority of attempts at producing weight loss, the weight loss and to a significant extent, it’s probably -- this would be causing the “disease” that they’re supposedly carrying. "
"In other words, the health problems that are associated with higher than average weight are to a significant extent, probably, simply a product of dieting; you know, the dieting industry itself is causing these health problems, which it supposedly is addressing through it’s use of expensive and dangerous interventions."
"I think that we could do an enormous amount of benefit for people in this country by focusing on what’s actually beneficial to health, which is being moderately physically active and avoiding eating disordered behavior and ignoring weight altogether, except in perhaps the most extreme cases where there seems to be some...I mean, this notion that everybody would be within a relatively narrow range of weight; if everybody has a healthylifestyle, it’s just utterly unscientific, it utterly is bizarre; its arguing that everybody who’ll be between 5 foot 7 and 5 foot 10 if everybody had a healthy lifestyle."