Hi David, good question. I was referring to the three body composition types: Ectomorph, Mesomorph, and Endomorph. Regrettably, the industry uses BMI as a gauge to determine if a person is of a healthy weight. However, under this system most bodybuilders would be deemed obese. I was eluding to having lower body fat levels and higher muscle tone (irrespective of your body composition) should be the measure of a healthy body type.