BMI – epic fail of the century?
How many of you have heard for Body Mass Index or BMI for short?
Take your height, weight, divide something with something and you get BMI?
Ok, the true formula: weight in kg / height in meters².
Check wikipedia (link at the bottom) to see US units.
So, of course there is a table which will define the possibilities:
Severely underweight, BMI is less than 16.0
Underweight, BMI is from 16.0 to 18.5
Normal, BMI is 18.5 to 25
Overweight, BMI is 25 to 30
Obese Class I, BMI is 30 to 35
Obese Class II BMI is 35 to 40
Obese Class III BMI is over 40
Image via Wikipedia
After reading a few good online articles about BMI, it hit me also, as did many other authors of various articles. BMI takes into consideration only your weight and height!
What about bone structure, muscle mass, waist and hip size/ratio, is the person an athlete, etc.?
Nothing.
If you google up BMI, and click on the wikipedia link, there’s a great read from which century(!) BMI is:
The body mass index (BMI), or Quetelet index, is a heuristic proxy for human body fat based on an individual’s weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing “social physics”.[1] Body mass index is defined as the individual’s body weight divided by the square of his or her height. The formulae universally used in medicine produce a unit of measure of kg/m2.
Between 1830 and 1850? And we still use that? How many sites still use BMI? Fitbit does for example. And many, many others. Somebody pass me a wooden fork please and the keys to my car which runs on coal and steam.
How many doctors still use BMI to advise their patients, specially kids, about their weight?
Now, don’t even get me started on Body Fat Percentage. How great it is to measure it with the scale you have in your bathroom. Another great fail.
I highly recommend reading this article (links to a PDF!) titled Do you believe in Fairies and Unicorns, or the BMI, which describes BMI in great detail and explains why it should not be used.
