Insurance companies sometimes charge higher premiums for people with a high BMI. 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. It suggests there are distinct categories of underweight, ideal, overweight and obese, with sharp boundaries that hinge on a decimal place.Ĩ. Averages measure entire populations and often don't apply to individuals.īecause 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. 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. But it gives exactly the wrong answer for a large and significant section of the population, namely the lean, fit and healthy. It applies moderately well when applied to such people because it was formulated by focusing on them. It could mean the person is fit and healthy, with very little fat.īecause 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. A high BMI does not mean an individual is even overweight, let alone obese. But as with my birthday present, it doesn't work the other way round. Because of how Quetelet came up with it, if a person is fat or obese, he or she will have a high BMI. If I tell you my birthday present has wheels, you cannot conclude I got a bicycle. But it does not work the other way round. For example, if I tell you my birthday present is a bicycle, you can conclude that my present has wheels. 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.
#Craps calculation tool movie
Thus, athletes and fit, health-conscious movie stars who work out a lot tend to find themselves classified as overweight or even obese. 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. It makes no allowance for the relative proportions of bone, muscle and fat in the body.
Moreover, it ignores waist size, which is a clear indicator of obesity level. If you can't fix the data, rig the formula!).
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. In other words, it is a 200-year-old hack. 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.
The BMI was introduced in the early 19th century by a Belgian named Lambert Adolphe Jacques Quetelet. 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 study found that nearly two-thirds of states now have adult obesity rates above 25 percent.īut you may want to take those findings - and your next meal - with a grain of salt, because they're based on a calculation called the body mass index, or BMI.Īs the Weekend Edition math guy, I spoke to Scott Simon and told him the body mass index fails on 10 grounds:ġ. Americans keep putting on the pounds - at least according to a report released this week from the Trust for America's Health.
0 kommentar(er)
