Is BMI the “Weigh” to Go?

What is BMI?

BMI (Body Mass Index) is a measurement of body fat based on height and weight that applies to adult men and women over the age of 20. Invented by Belgian mathematician Adolphe Quetelet in the early 19th century, BMI is calculated by dividing your weight (in kilograms) by your height (in meters squared). Over the years, BMI has become an easy and quick way to determine if a person is underweight, normal or healthy weight, overweight, or obese. According to the CDC, adults 20 years and older should follow these standard categories:

How accurate is BMI in determining health?

Calculating your BMI, weighing yourself on a scale...how much good do these methods do? There has been a lot of discussion over the accuracy of BMI, and the research doesn’t look very promising. That’s because BMI has many limitations, namely, it can tell you if you're carrying too much weight, but it cannot tell if you're carrying too much fat. BMI does not consider age, gender, ethnicity or muscle mass, which as well all know are crucial factors when talking about overall health.

For athletes, BMI can be especially tricky because muscle is denser than fat, which often results in a higher weight. Would you consider pro athletes like Tom Brady and Lebron James to be overweight or obese? Well, according to their BMI score, they are. However, an athlete with a higher muscle mass and a higher BMI is much healthier than someone with a lower BMI but more body fat. BMI does not apply to pregnant women, children or the elderly, who lose muscle and bone mass but can still be considered unhealthy. 

What should I do instead of calculating my BMI?

We’ll let you in on a little secret: measuring your waist circumference is a much better indicator of health compared to BMI. Why? Because belly fat is the most dangerous type of body fat you can have. Also known as visceral fat, it lies below your abdomen and surrounds your liver, stomach, kidneys, and intestines. Belly fat is linked to a greater risk of heart disease, type 2 diabetes, and high blood pressure.

To determine your waist circumference, take a tape measure and measure your waist just above your hip bone. Hold the tape measure tight, and relax your stomach without sucking in. For women, 35 inches and over indicates an unhealthy amount of belly fat, while for men it’s 40 inches or more.

Hydrostatic weighing (aka underwater weighing) and MRI scans are two more ways that you can calculate your overall weight that is more accurate than BMI.

At the end of the day, everyone’s body is different and there is no such thing as the “perfect weight.” Additionally, there is no “one size fits all” and a few decimal points here and there won’t really tell you if you’re healthy or not. While calculating your BMI can be a good starting point, it isn’t the be-all, end-all. With advances in medicine and technology in today’s world, there are simply more effective ways to assess body composition. Instead of stepping on a scale, focus on eating a balanced diet, exercising regularly, drinking alcohol in moderation and living a stress-free life. After all, your health is more than just a number.

Do you think BMI is just a number? Let us know in the comments below!