Using BMI as an indicator of body fatness is like saying that one shoe fits all. It doesn’t work that way. There are three basic body types – ectomorph, endomorph and mesomorph.
An ectomorph is a thin, small bone person with very little muscle mass. Most models are ectomorphs and, unfortunately, have been used to set the standard as to what we all should look like – very unreal. An endormorph has more muscle and larger frame size (medium bone) but can easily assume the shape of a pear if one is not careful. A mesomorph is known as a stocky individual with large bones and much muscle.
Here is the irony with BMI. Many mesomorph persons are labeled obese when in fact they are not and many ectomorphs are labeled normal weight and some case underweight when in fact they could be obese.
It is possible that obesity can exist within each of these three body types (somatotypes). But we must be careful when using BMI to take into consideration body type before making a final determination for obesity.
This would be particularly true if you wanted to lose weight. Some weight loss goals could be unrealistic because the individual is a mesomorph trying to look like an ectomorph. You can’t change your frame size so work with realistic weight loss goals that fit your frame size. Your goal should be to achieve a healthy body weight. To learn more about achieving a healthy body weight, check out Move It. Lose It. Live Healthy. Achieving a Healthier Workplace One Employee at a Time! found in the Shop section on this web site. 
