You may be familiar with the BMI or body mass index. It is that chart you may have seen that tells you if your weight matches your height as healthy. Different from simply stepping on your bathroom scale, which calculates only total weight, the BMI is supposed to give you an idea of how much fat you’re carrying around. It is found by multiplying weight by 700 and dividing the answer by height in inches then dividing that result, again, by height in inches toreach a number which corresponds to a chart listing ranges telling you if you are underweight, overweight, or obese. The World Health Organization considers a BMI of 18.5 to 24.9 to be a healthy reading.
Doctors have been known to use the BMI as a starting point for determining health, so you might assume it is the standard for fat measurement. The formula was created by a Belgium statistician, Adolphe Quetelet, in the mid 1800s. His work, generally, focused on what characterized the average man. While considered groundbreaking, the BMI is really limited as it cannot differentiate lean weight from fat; a big problem. Since muscle weighs more than fat, when using the BMI a stocky athlete would probably be categorized as overweight or obese. If Jay Cutler (bodybuilding’s Mr Olymipa 2010) were to enter his height (5 feet 9 inches, or 175 cm) and weight (270 pounds, or 122 kg) into a BMI calculator, his BMI reading would be around 40 — seriously obese. But while Cutler typically eats about 6,500 calories of food a day, he is very lean and typically enters competition with low single-digit fat levels.
The body mass index also fails to calculate other imporatant factors, such as race, sex, and age. Since women need more body fat and muscle mass tends to decline with age many using only the BMI to determine health would be thinking themselves over or underweight when the opposite is the case. The Mayo Clinic points out another fatal flaw by stressing that a person carrying excess weight in the abdomen is at greater risk of disease than a person carrying excess weight in the hips. The body mass index can be a useful tool to begin the search for your ideal body weight, but it has serious flaws.