Overweight not so bad?

scale by atomicjeep
Obesity Apocalypse:
[Via Lawyers, Guns and Money]

Even by the remarkably mendacious standards of the “obesity” racket some of the claims in this story are beyond belief.

The most laughable is the idea that by 2048 everybody in the US will be “overweight” or “obese.” This result was derived via statistical extrapolation, the crack cocaine of social science analysis (by similar methods one could prove that within a few generations Olympic sprinters will be running at speeds that will hurl them into low Earth orbit and everyone in America will have a plasma TV seventeen miles wide).

In fact there has been no weight gain at all over the past 30 years in the thinnest quartile of the population — whatever (poorly understood) factors have caused Americans to weigh more on average now than they did in the 1970s have had very different impacts across the weight spectrum: thin people have gained no weight, people in the middle weigh 10-15 pounds than they did 30 years ago, while the fattest people have gained a lot of weight, which is exactly what one would expect. Furthermore, as even this story manages to note, there’s quite a bit of evidence that the trend toward weight gain in the populace in the 1980s and 1990s seems to have plateaued.

The problem is that ‘everyone’ knows that being overweight or even obese is tremendously bad for your health, right? Well, if you actually look at the data, not so much.

Now if we’re facing an “apocalypse” because of “overweight” and “obesity,” we should see evidence of this in, at the very minimum, increased relative risk of mortality among people in these categories. Here’s the relevant data from NHANES III on mortality risk. The following statistics use the mortality risk found among supposedly “normal weight” (sic) people (BMI 18.5-24.9) as the referent group. In other words, the mortality risk for this group sets the baseline for comparison to other groups in terms of their mortality risk. A group that has a higher mortality risk than the referent group will have excess deaths over the baseline risk. A group that has a lower mortality risk will have fewer deaths than would be seen in the group if it had the same mortality risk as the referent group of “normal weight” people.

Most recent excess deaths estimates from NHANES III:
Underweight: 38,456
Normal weight: 0
Overweight: -99,980
Obesity Grade I: -13,865
Obesity Grade II and III: 57,515

Underweight less than 18.5 BMI, normal weight 18.5-24.9, overweight 25-29.9, Obesity Grade I 30-34.9, Obesity Grade II and III 35+ What these numbers mean: In the US population at present, we are seeing about 100,000 fewer deaths per year among “overweight” people than we would if “overweight” people had the same mortality risk as “normal weight” people. Note that the majority of people in the US who according to the government’s current classifications weigh too much are in this group. The “overweight” category is to the obesity panic what marijuana use is to the drug war: stories about an “epidemic” of fatness depend crucially on classifying the 35% of the population that’s “overweight” as being at some sort of increased health risk. This is simply false, and is known to be false by the researchers who are quoted in stories like the one linked above.

So, being overweight may not be the harsh sentence the media makes it out to be. The people who are overweight, as a group, are not generally at a higher risk than normal weight people. Perhaps they are at increased risk for certain diseases but it may not effect their overall mortality.

What this does show is that BMI is probably worthless for developing a meaningful understanding of the effect of greater weights on human disease. It just gets used because it is easy to measure, not because it is really diagnostic.

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One thought on “Overweight not so bad?

  1. Another example of females taking over the world. Remember, it was a woman who said, “You can never be too rich or too thiin?

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