Doctors have long known that obesity is a significant health risk, especially for cardiovascular disease and diabetes. Overweight people can be just that—overweight—or they can be placed in specific category called Clinical Obesity. This category has a more significant effect on the health of individuals. It has been found that the excess body fat present in clinical obesity is directly responsible for increasing the risks of developing heart disease, diabetes, and mobility limitations. Clinical obesity itself is a chronic disease that needs specific, focused treatment.
So, rather than assessing risk by using a parameter that takes into account only height and weight, the Body Mass Index, BMI, a new parameter is now being used to better assess the presence of clinical obesity and to evaluate its significance to that patient. BMI alone is inadequate for assessing whether excess body fat is harmful to your health. Actually measuring body fat is the method that answers the question of clinical importance.
The new measure is called the Relative fat mass index (RFM). RFM is an anthropometric (a measurement of the size and proportions of the body) determination of the percent of fat in the patient’s body based on an individual’s gender, height, and waist circumference. There is a specific formula to calculate this index. The result is expressed in percent body fat.
THE FORMULA:
RFM = 64-(20 x height/waist circumference) + (12 x sex 0 Male and 1 Female)
My RFM would be: 64-(20 x 76”/46”) + 12 x 0 = 33%. OR 64-(20 x 1.65) + 0 = 33% body fat
My Relative Fat Mass Index (or percent body fat) is 33%
RFM is a better and more consistent predictor of CVD and mortality. A higher RFM is associated with substantially increased mortality risk. In other words, the higher the Relative Fat Mass Index, the greater the risk of cardiovascular disease and death. For comparison sake, the ranges below have been deemed significant:
Women with 40% or > and Men with 30% or > had a 50% higher risk of death than women with < 35% and men < 25%.
AND
Women with 45% or > had double the risk of death and Men with 35% or > had 2.5 times higher risk of death.
My 33% puts me in the high risk category!
RFM is the strongest anthropometric risk predictor currently available for heart attack, heart failure, and diabetes in adults. It gives doctors more pertinent, specific prognostic information and should point out to everyone the risk at which we place ourselves when we’re clinically obese.
Inconsistent measurement of waist circumference is a limitation that threatens accuracy and reliability, but RFM is a better tool for identifying those individuals whose clinical obesity places them in a high risk population.
Reference: Apovian CM. Can Relative fat mass Replace BMI in Assessing Obesity? Medscape 2025 December 29.
