Typical measurements such as height, weight and BMI (body mass index) have important limitations in determining body status from a health risk perspective. Generally lean mass such as muscle is highly metabolic and disease preventative, while central (belly/hip) fat mass is disease causing.
Several variations in body type make simple measurements such as weight and BMI misleading in a large portion of the population. Large framed (bone and muscle) persons often have an abnormally high BMI yet very little metabolic disease risk. More commonly others may have lost lean mass and gained fat mass resulting in normal weight and BMI. This body mass type has been termed “metabolically obese, normal weight” (MONW) and carries a very high metabolic disease risk in spite of the normal weight.
Clinical body composition analysis uses fixed electrodes through which a microcurrent is run between electrodes. This results in an impedance or resistance measurement which then can be used to accurately determine lean and fat mass. This system measures these parameters to an accuracy of +1% versus metal plated scales or handheld models where accuracy is typically +5-6%. In a 180 lb individual a 5-6% error is 9-11 lbs which is too large a margin of error for clinical use.
Below is an example of a body composition analysis of a patient who has a MONW profile with a very high metabolic disease risk in spite of being “normal weight”.
Weight does not independently predict health risk. Rather it is how high weight is distributed between the lean and central fat body compartments. It is equally important to add lean mass while losing central fat mass for ideal risk reduction.