The Great Fraud: BMI and how it is hurting us all

[GraceAbounds 11]

While modern medicine continues to astound us all with innovation that makes life better for so many - it has failed us greatly when it comes to how health is measured using Body Mass Index. And, if it is not changed, many of us will pay the price for years to come for this total fraud in health care. You will pay higher premiums not only for health insurance but eventually for car insurance (study just released that shows higher BMI equals greater risk of injury in car accident). It is a free ticket to higher profits for companies who know how to slant this in their favor. Check out this article from NPR:

http://www.npr.org/templates/story/story.php?storyId=106268439 1. The person who dreamed up the BMI said explicitly that it could not and should not be used to indicate the level of fatness in an individual.

The BMI was introduced in the early 19th century by a Belgian named Lambert Adolphe Jacques Quetelet. He was a mathematician, not a physician. He produced the formula to give a quick and easy way to measure the degree of obesity of the general population to assist the government in allocating resources. In other words, it is a 200-year-old hack.

2. It is scientifically nonsensical.

There is no physiological reason to square a person's height (Quetelet had to square the height to get a formula that matched the overall data. If you can't fix the data, rig the formula!). Moreover, it ignores waist size, which is a clear indicator of obesity level.

3. It is physiologically wrong.

It makes no allowance for the relative proportions of bone, muscle and fat in the body. But bone is denser than muscle and twice as dense as fat, so a person with strong bones, good muscle tone and low fat will have a high BMI. Thus, athletes and fit, health-conscious movie stars who work out a lot tend to find themselves classified as overweight or even obese.

4. It gets the logic wrong.

The CDC says on its Web site that "the BMI is a reliable indicator of body fatness for people." This is a fundamental error of logic. For example, if I tell you my birthday present is a bicycle, you can conclude that my present has wheels. That's correct logic. But it does not work the other way round. If I tell you my birthday present has wheels, you cannot conclude I got a bicycle. I could have received a car. Because of how Quetelet came up with it, if a person is fat or obese, he or she will have a high BMI. But as with my birthday present, it doesn't work the other way round. A high BMI does not mean an individual is even overweight, let alone obese. It could mean the person is fit and healthy, with very little fat.

5. It's bad statistics.

Because the majority of people today (and in Quetelet's time) lead fairly sedentary lives and are not particularly active, the formula tacitly assumes low muscle mass and high relative fat content. It applies moderately well when applied to such people because it was formulated by focusing on them. But it gives exactly the wrong answer for a large and significant section of the population, namely the lean, fit and healthy. Quetelet is also the person who came up with the idea of "the average man." That's a useful concept, but if you try to apply it to any one person, you come up with the absurdity of a person with 2.4 children. Averages measure entire populations and often don't apply to individuals.

6. It is lying by scientific authority.

Because the BMI is a single number between 1 and 100 (like a percentage) that comes from a mathematical formula, it carries an air of scientific authority. But it is mathematical snake oil.

7. It suggests there are distinct categories of underweight, ideal, overweight and obese, with sharp boundaries that hinge on a decimal place.

That's total nonsense.

8. It makes the more cynical members of society suspect that the medical insurance industry lobbies for the continued use of the BMI to keep their profits high.

Insurance companies sometimes charge higher premiums for people with a high BMI. Among such people are all those fit individuals with good bone and muscle and little fat, who will live long, healthy lives during which they will have to pay those greater premiums.

9. Continued reliance on the BMI means doctors don't feel the need to use one of the more scientifically sound methods that are available to measure obesity levels.

Those alternatives cost a little bit more, but they give far more reliable results.

10. It embarrasses the U.S.

It is embarrassing for one of the most scientifically, technologically and medicinally advanced nations in the world to base advice on how to prevent one of the leading causes of poor health and premature death (obesity) on a 200-year-old numerical hack developed by a mathematician who was not even an expert in what little was known about the human body back then.

[GraceAbounds 11]

_{Full link to the original article from NPR: http://www.npr.org/templates/story/story.php?storyId=106268439}

[rubinsml 11]

We would be better off saying we have an elevated BMI due to obesity vs classifing ourselves as obese due to an elevated BMI. In other words a person can have a elevated BMI due to obesity or high muscle mass/low fat ratios or as you pointed out heavy bones along with high muscle mass.

[jen1211 203]

It's kind of funny that you posted this because I was just talking about it the other day. It is extremely frustrating to see this bmi scale and what it does to people. My sister started eating healthy and exercising and lost about 110 pounds. She exercises every single day, she is a runner and still eats healthy but she weighs about 210 which puts her bmi greater than 30 and of course means she has to go to weight watchers for insurance. It's ridiculous, she is healthier than some of her 120 lb friends but she still suffers because of the label of >30 bmi.

[CowgirlJane 14,259]

Well, I guess it is a rough guideline, but the height weight charts arent much better...

[SleeveandRNYchica 1,155]

I just posted something about there being way to much emphasis on BMI. What about body fat! There are "skinny people" that have high percentages of body fat. I do believe ere are so many other factors. I do not want to be "skinny fat" I want to be healthy and I am not sure that the BMI chart gets me to what I consider healthy. 125 lbs doesn't always equate to health for my height.

[GraceAbounds 11]

_{BMI is not only a poor indicator of health (how long and with what ability you will live) it is NO indicator of such a thing. It is a lie plain an simple. But it is a revenue generating tool for big companies who will and do charge higher premiums for folks who live on the upper end of this scale.}