To Your Health

February, 2017 (Vol. 11, Issue 02) Share |

BMI: Myth vs. Fact

By Editorial Staff

For years we've been caught up in the allure, for better or worse, of body-mass index (BMI). What's your BMI? Is it high, low or just right? Unfortunately, while the BMI has some benefits, it isn't necessarily the most accurate gauge of a person's health. Let's learn more about body-mass index and some of the myths vs. facts surrounding it.

Body-mass index measures a person's height (square meters) in relation to their weight in kilograms. Divide your weight by your height and you'll determine your BMI. Not hip to the metric system? Then multiply your weight by 703 and divide by your height in inches squared. Anything between 18.5 and 24.9 is considered "normal."

MYTH: If your BMI is high (25 or higher), it means you're overweight / at risk for health issues. The inaccuracy of body-mass index stems from its very nature of generalization; after all, can billions of unique individuals really be grouped into general categories based purely on height and weight? BMI fails to adjust for factors such as body type, muscle mass, etc., that can have a profound impact on the numbers.

For example, two 5 foot, 10 inch tall people who each weigh 175 pounds have a BMI of 25.1 – slightly overweight. But what if one is pure muscle and eats a clean diet, while the other is a couch potato who can't lift a finger without getting tired? Which do you think is healthier?

FACT: Body-mass index is more revealing when it comes to high and low numbers. BMI works better when it comes to people who are either markedly underweight or overweight / obese. If you're 5 feet, 6 inches tall and weigh 230 pounds, your BMI is 37.1 – way out of the normal range. Chances are good that even when accounting for your unique body type and exercise / diet habits, you may need to shed some pounds or risk health consequences down the line.

MYTH: Whether you're a woman or a man, the BMI can tell you a lot about your health. This is one of the biggest misconceptions. Unless you're using one of the latest BMI scales, which accounts (or tries to) for gender (as well as age in some cases), you're not getting enough useful information from your BMI score. Age and gender are both important variables to consider, since women naturally tend to retain more body fat than men, as do older vs. younger people.

Rather than rely on BMI as a true measure of your health, a better indicator may be waist circumference (WC). Increasing research suggests waist circumference is a stronger predictor of intra-abdominal (visceral) fat than BMI. This is an important distinction because visceral fat, situated between the abdominal organs, can impact body function to a greater extent than subcutaneous fat, which is situated just under the skin. To learn more about waist circumference and how to measure it, talk to your doctor and click here.