Invariably, the anti-BMI people will point out some professional wrestler or football player that has a high BMI but the fact is, those professional wrestlers and football work out for hours each day which is something Mr. Couch Potato doesn't do. Also, these professional atheletes have to retire someday and when they do, it all catches up to them pretty quickly unless they change their ways and get that BMI down.
"Actually the BMI is a pretty good indicator of your general health. "
No, it's not.
Body fat percentage is a "pretty good indicator". The BMI approximates that number, but obviously it's a poor indicator. It is a crude method that supposedly replaces much more precise (but more costly) methods, such as the dunk tank method, or even the skin pinch test. The BMI is akin to saying that we know the condition of an automobile by looking at the tires.
Athletes blow the scale out of the water due to muscle mass, especially those who have massive leg muscles (bicyclist, including Lance and Dubya and me).
In addition, different ethnicities experience health effects at different BMIs as their body responds differently to fat mass and body build. Oriental people, for instance, run into health problems at a lower BMI than causasians.
This is a bit redundant with post 15, but it's worth clarifying that BMI is NOT a diagnostic tool. IOW, you can't use it as anything more than a screening tool for individuals.
From the CDC website:
BMI is used as a screening tool to identify possible weight problems for adults. However, BMI is not a diagnostic tool. For example, a person may have a high BMI. However, to determine if excess weight is a health risk, a healthcare provider would need to perform further assessments. These assessments might include skinfold thickness measurements, evaluations of diet, physical activity, family history, and other appropriate health screenings.
link:
http://www.cdc.gov/nccdphp/dnpa/bmi/adult_BMI/about_adult_BMI.htm
I was a gymnast who put muscle weight on fairly easily.
In college my teammates were pretty similar to me in height, weight, and muscle mass.
Our coach told us we were officially "overweight"- but after awhile she decided to have our bodyfat tested through underwater weighing.
Our percentages ranged from 7% to 13%.
To this day I ignore the official charts and go by pinching bodyfat, and how my clothes are fitting me.