This whole topic reminds me a lot of the issues with the BMI index used by doctors and health insurance companies. Using a scale based on the average American who is your same sex, age, and height is not going to yield an accurate result when comparing it to someone who has a lot of muscle mass from lifting or athletics. Alot of lifters would be classified as obese or morbidly obese when comparing themselves to a benchmark based on the "average" person.