Urban-- I found this article for you:
http://www.femalemuscle.com/q_a/question30.htm
The guy who wrote it is a body builder, nutritional specialist and personal trainer.
Here's what I thought you'd like to read:
"Why is BMI a poor measure of health and fitness? It's simply because BMI does NOT take into account body fat vs. lean tissue. Body builders and other athletes carry more lean body mass than the average person and will therefore be classified as overweight if BMI is used as the criteria for measurement. Conversely, someone could have a "healthy" BMI of 19 to 22 and yet have a dangerously high level of body fat (a "skinny fat person").
The solution of course, is to differentiate between your lean body weight and your fat weight. This can be done with body composition testing. There are many ways to test body fat, but the method I recommend is skinfold testing (the "pinch" test). You'll get the most accurate reading if you have an experienced tester measure you at three or four skinfold sites, but if you don't have access to an experienced professional, you can test your own body fat with a home testing kit called the Accu-Measure. The Accu measure tests total body fat with a single skinfold pinch on your iliac crest (hip bone). I bought a set for myself (very inexpensive) and I found that the measurements were fairly close to the measurements I got from the $450.00 computerized "Skyndex" calipers we use at our health clubs. You can order the Accu Measure caliper at:
http://www.bodytrends.com/acm.htm
In conclusion, body fat percentage is the only way to go. BMI is a poor indicator of your health, fitness or ideal weight. Forget about BMI - and while you're at it, forget about those Metropolitan height and weight tables too. According to the ideal weight tables, a man 5' 8" tall with a medium frame should have an ideal weight of 138 - 152. That means I need to lose at least 49 pounds!"
Urban-- I found this site by googling for it-- maybe you could find some other articles online to help you out!