Kylee Moss, a 7-year-old-girl from Belton, Missouri, was sent home from school with a note to her mother saying that the 54-pound child’s Body Mass Index (BMI) was too high.
Aside from the idiocy of using a discredited measurement for body fat, what are these administrators thinking? Obviously, they’re not. If they had two working brain cells, they would take one look at this kid and realize the stupidity of believing their “measurements.”
The leader of the Belton School District is promising changes after a girl came home from school with a note saying that her body mass index was too high.
Kylee Moss’ mother said she was infuriated when her daughter brought home the note from Hillcrest Elementary last Friday, along with a recommendation for healthy snacks and more physical activity.
“She goes, ‘Does this mean I’m fat?’ and I said, ‘No, this does not mean you are fat,'” said Amanda Moss.
Kylee, 7, stands 3 feet 10 inches tall and weighs 54 pounds. Her mother said she’s as active a second-grader as you’re likely to see.
“She is tiny. She has no body fat at all,” said Amanda Moss.
And this kid has energy to burn.
The BMI is a bogus measure of body fat. How bogus?
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.
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.
Bottom line: “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.”
But it’s only partly the school’s fault — the part where they totally embarrassed a 7-year-old girl and gave a shock to her self esteem. The BMI is still used by public health officials across the country and around the world. This “snake oil,” as the author above calls the BMI, is virtually worthless in cases of extreme malnutrition. Also, it doesn’t take into account relative musculature and body build.
There are other ways to calculate BMI, but those require specialty machines which are more expensive than just plugging in a mathematical formula. So despite the BMI being proved as an unreliable measurement, it looks like we’re stuck with it.
For the sake of Kylee Moss and an unknown number of other kids who are misidentified as having too high or too low BMIs, schools should get out of the business of tagging children as either too fat or too thin and leave the guesswork to the family doctor and to parents.
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