What is BMI? Numerical Hocus Pocus

The first thing you need to understand is that in our twilight zone of fat hysteria, I am officially obese, okay overweight. That’s based on the Body Mass Index (BMI), a measurement that separates us into government-approved, overweight, and obese categories by taking into consideration only our height and weight. A BMI of 30 or more makes you obese, and at 5-9, 184 pounds, I have a BMI of 27.2.

According to the BMI standard, 61% of America are fat or obese. You have probably heard that number. Along with the claim that obesity costs the United States $117 billion a year and kills 300,000 USA annually, it is one of the three most commonly cited figures associated with our so-called obesity epidemic.

But it’s more like an epidemic of bad statistics. All three of these numbers are seriously flawed.

Thanks to the absurdities of the BMI yardstick, Sylvester Stallone (5-9, 228 pounds, BMI of 34) and Mel Gibson (5-9, 214 pounds, BMI of 32) are “obese.” So was Mark McGwire (6-5, 250 pounds, BMI of 30) the year he hit 70 home runs. And if politics is your thing, you’ll be interested to know that the former Governator of California (6-2, 257 pounds, BMI of 33) is obese, too.

Here’s how the Centers for Disease Control and Prevention explains these counterintuitive results: “Overweight may or may not be due to increases in body fat. It may also be due to an increase in lean muscle.”

It’s not just full-blown obesity that has been bungled by numerical hocus-pocus. 39 million Americans went to sleep one night in 1998 at a government-approved weight, and woke up “overweight” the next morning, thanks to a change in the government’s definition. That group includes presently “overweight” (BMI greater than or equal to 25) movie stars like Will Smith (6-2, 210 pounds, BMI of 27) and Pierce Brosnan (6-2, 211 pounds, BMI of 27). Michael Jordan (6-6, 216 pounds, BMI of 25) and Cal Ripken Jr. (6-4, 220 pounds, BMI of 27) were also “overweight” at the height of their athletic powers.  Moreover, the standard that we abandoned in 1998 had the virtue of distinguishing between men and women–something we now do not even attempt to do.

Is this insanity or just plain bad statistics. The regularly recycled factoid that excess weight causes 300,000 deaths a year bizarrely assumes that if you die while overweight, you die because of that excess weight. As insane as it sounds, if I were to kick the bucket for any reason, my death would count toward the mythical 300,000 total.

The respected New England Journal of Medicine knows this is bogus. It maintains that the 300,000 figure “is by no means well established. Not only is it derived from weak or incomplete data, but it is also called into question by the methodologic difficulties of determining which of the many factors contribute to premature death.”

Nevertheless, this statistic finds its way into nearly every discussion of obesity–as does the spurious claim that obesity costs Americans $117 billion per year. The source of this figure: a single study published by the journal Obesity Research in 1998.

This study had serious limitations, as the authors themselves admitted. They acknowledged that their methodology resulted in the “double-counting of costs” which “would inflate the cost estimate.” There’s also this stunning admission: “We are still uncertain about the actual amount of health utilization associated with overweight and obesity. Height and weight are not included in many of the primary data sources.”

But even if they had good data to work with and somehow controlled for the double (and even triple) counting of costs, these researchers still would have reached a unrealistic conclusion. Why? They used the wrong definition of obesity.

A BMI of 30 or more makes you obese, but the authors of this study for some reason decided to set the threshold at “BMI greater than or equal to 29.” Thus they erroneously included the economic cost of individuals with a BMI between 29 and 30. A small error? Not at all. That covers more than ten million Americans, including Bruce Willis (6-0, 211 pounds, BMI of 29), Brendan Fraser (6-3, 234 lbs, BMI of 29), and George Clooney (5-11, 211 pounds, BMI of 29).

$117 billion cost. 300,000 deaths. 61 percent overweight or obese. All wrong. Unfortunately, these bad statistics are the shaky ground on which a growing number of activist groups seek to build their nutritional utopias. Gotta trust the government, right? Makes one wonder if all those vaccine stories are true...