In 2006 the geniuses in Albany passed legislation requiring every school child in the state of New York to have their BMI (body mass index) calculated and reported to the state. The purpose of this data collection is unstated. The eventual use of this data is unknown.
At its June 2nd meeting Dr. Adrienne Weiss announced with great pride that New Rochelle had been “selected” to participate in this study. What an honor! It would be nice to think that before they popped the champagne corks over at City Hall they might actually understand what BMI does and does not measure and then perhaps even realize that BMI is an utterly pointless statistic when applied to individuals.
To get a better understanding of just how stupid the BMI is as a measure of the fitness of a particular individual consider the following:
- In 2005, the Associated Press did a study and found that half of the players in the NBA were "overweight" based on their BMI.
- The Journal of the American Medical Association did a study that found that half of the players n the NFL were "overweight" based on their BMI.
- Hollywood movie stars such as George Clooney, Matt Damon, Johnny Depp, Brad Pitt, Will Smith and Denzel Washington are all considered overweight based on their BMI.
- Kobe Bryant is classified as "overweight" and Shaquille O'Neal is "obese".
If you still think the Body-Mass Index is a meaningful measure of fitness, a few minutes listening to Keith Devlin of Stanford University should erase any lingering doubts. Appearing with Scott Simon on NPR's Weekend Edition, Devlin notes that the BMI classifies as overweight the most fit people in our society including Devlin himself, an avid cyclist who logs over 200 miles a week on his bike and has a 32 inch waist.
Devlin provides a list of the Top 10 Reasons Why The BMI Is Bogus and provides a description of the formula and the CDC Scale. Devlin points out that BMI was developed by a mathematician -- not a physician -- to help the Belgian government allocate government resources based on the obesity of the general population. The formula was created to match the government data; there is no physiological reason to square a person's height to determine fitness. The BMI ignores waist size which is the most obvious and clear-cut indicator of obesity level and makes no allowance for the relative proportions of bone, muscle and fat in the body of different individuals. The BMI is entirely illogical. The formula was created to fit the data; fat people will have a high BMI but a high BMI does not mean an individual is overweight, let alone obese. In fact, a high BMI could just as easily indicate a person is fit and healthy, with very little fat.
The BMI Formula
BMI = weight in pounds/(height in inches x height in inches) x 703
The 703 is to convert the index from the original metric version of the formula.
Below 18.5 = Underweight
18.5 to 24.9 = Ideal
25.0 to 29.9 = Overweight
30.0 and above = Obese
As should now be obvious, the BMI is a popular but essentially useless predictor or evaluator of obesity. For instance, a large boned muscular student of average height may very well have a BMI that suggests he is obese. This is true because muscle and bone are far more dense than fat. A short, slender perfectly health child could be diagnosed as being underweight by a low BMI. There is no valid reason or excuse for this measurement. But, you may argue, the schools measures a child’s hearing and visual acuity. Is this not the same? No, it is not. Hearing and visual acuity have a direct bearing on education. I know of no relationship between weight and scholarship.
The BMI was invented some two hundred years ago by a Belgian mathematician as a way to evaluate large populations. There was never any claim by its inventor that it had diagnostic value in an individual. In fact it does not. Either the waist to hip measurement or skin fold measurements are far superior. Is there any parent reading this who cannot tell if their child is overweight? Is there any parent who needs a government agency to tell them that their child is overweight?
But this is more than just another bit of governmental stupidity. This is another of the seemingly endless intrusions into our personal lives in which government at every level loves to indulge. It goes right along with the census taker wanting to know how many toilets there are in the house or what time we go to work in the morning.
Do we have any idea how this information will be used -- or abused? BMI might not actually tell you anything useful about fitness but could still be use by an insurance company to justify increasing premiums on a family or canceling a policy. Certainly nothing good is going to come from collecting this data.
Perhaps the school could use this information to schedule three lunch lines; one for "overweight" children, one for "underweight" children and one for “normal" children. The menu items could be restricted based on BMI! Anyone want to see that happen? Now that would make for a great educational experience!
Have we not had enough of these self-important and ignorant fools intruding their personal bias into our lives? Enough and more than enough. Parents need to raise their voices and object to this unwarranted invasion of their children’s privacy. At the very least, parents should notify the school they wish to opt-out of the program.