It seems that everyone knows their body mass index or BMI. So much of our self-image is driven by this one number! The BMI was created to relate our height and weight to a universally accepted ratio of body fat. Did you know that the rules changed without anyone telling us?
Your BMI is defined as your weight, times 703 divided by the square of your height in inches. Before 1998, the meaning of the resulting number in the US was not aligned with the scale used by the World Health Organization. That change was pretty tough on Americans.
Looking at the world as a whole can lead you to believe that the “average” human is a pretty lean individual. Life in America is a bit different. The BMI scale does not consider these cultural and dietetic differences.
Under the post-1998 scale, about 55 percent of the U.S. population is in the “overweight” category of the BMI scale. Ouch, that’s pretty harsh. It might make you feel better to know that pro baseball MVP Cal Ripken Jr. is also overweight using this scale. Really?
The creeping danger of this sliding BMI scale is apparent when you visit your doctor. Let’s suppose you have a sore knee. Is your BMI in the overweight category? If so, you will probably be told that you need to lose 20 pounds to make your knee better. That’s it. If you have a BMI of 25 you are now responsible for every ailment because of your weight. Bam. Forget an MRI or an anti-inflammatory, you need a diet before you can get real medical help. If you had the same doctor’s visit in 1997, you wouldn’t be overweight and the doctor would actually work to solve your issue.
This tyranny of the BMI is slowly becoming visible to the public and academia. Some doctors have moved beyond knee-jerk assumptions around BMI ranges and resumed treating their patients as individuals instead of numbers on a graph. In many cases, however, the American populace, now judged overweight, skips doctor visits to avoid being told, “lose 20 pounds and come back to see me.”
Without question, obesity is a real health issue, especially in the U.S. But one’s BMI should be given no more credence than a blood pressure reading when treating a patient. It is time for doctors to reopen their eyes.