The BMI (body mass index) was originally created for insurance companies so that they could show policyholders the mortality rates of overweight people. It was thought-up in 1832 by Adolphe Quetelet, a mathematician who set out to define the standard human body within the parameters of height and weight. But there's no question that the human body is so much more than just height and weight.
The equation relates those two elements, dividing height by weight to give a composite number falling anywhere between 18 and 40; that number could be seen as a rough sketch of how your body compares to the overall population in terms of fat content. In one regard, the BMI can be useful insofar as providing general data that helps doctors understand risk factors for a large subset of the population. But on a personal level, those two elements (weight and height) fall short of providing an accurate depiction of a person's physiology. The equation does not take into account gender, body frame, ethnicity, age, exercise or eating habits.
Why so many doctors and health gurus find it outdated is because the formula does not differentiate between muscle and actual fat. Victor Adam of Axiom Health and Fitness explained that "what makes this useless as a determining factor for health is that it is very unspecific, since it doesn't account for lean body mass. Someone who is 250 pounds of solid muscle at 5’6” puts them at a BMI of 40, which by this measurement says this individual is very obese and exceptionally unhealthy. While this is obviously an extreme example, it shows you the limits of this particular measurement — which is why it is not good for much more than offering you an initial indicator of the health of your weight for your height."
For people who have larger frames, lots of muscle mass or higher bone density, the BMI ratio would be misleading. Also, the BMI does not take into account where fat is located. Visceral fat, another term for belly fat, is far more dangerous to a person's health than fat located around the buttocks or thighs. Visceral fat crowds organs and can interfere with how they function.
>> Read more: 5 Ways to Get Rid of Belly Fat Forever
Based on the BMI alone, many hardcore athletes would be considered overweight, even obese, because they lift heavy weights or run cross country and have tree-trunk thighs. On the other hand, someone could be a couch potato all day every day, and still have a BMI that falls within the healthy range. Hands down, tons of doctors and health coaches find the BMI tells a poor tale about a person's health.
Dr. Scott Schrieber, a chiropractic physician that is double board certified in rehabilitation and clinical nutrition, said about determining body composition that "there are better choices, such as a percent body fat read, a waist to hip ratio, hydration status, ideal body weight, but not one method is superior than the other. We need to look at many measures for the individual, rather than globalize the entire human population into one test."
If accuracy and truth about your health are important, there are more accurate methods available today. By getting a reading on your body fat percentage, you'll get a very accurate idea of how much extra fat you carry as well as how many calories your body naturally burns. This can be done through your primary care physician. A waist-to-hip ratio you could do yourself! Registered dietitian, Amrie DeFrates, from California also pointed out that "though there are studies that show obesity as a risk factor for diseases such as heart disease and diabetes, there is also significant evidence to show that good health is absolutely achievable at any size." Meaning, your health is not dependent on how much you weigh. What matters more is that you eat right, treat your body kindly, and most importantly, are happy.