What is Body Mass Index?

Obesity is becoming a larger issue to battle in the United States. According to the State of Obesity, adult obesity rates now exceeds over 20% in the US alone – which is astonishing. That’s where the body mass index (BMI) comes in. The BMI is a measure of body fat based on weight and height, which is used to help control weight levels.

If you have ever taken a standard physical education course, there’s a good chance you’ve had to measure your body mass index. However, measuring your BMI isn’t just for physical education. It is also used in doctor’s offices, clinical practices, nutritionist offices, and just about anywhere that requires a weight screening. You can also calculate your BMI in your own home!

In today’s post, we’ll be taking a closer look at the body mass index, how to measure it, and why it’s important.


What is body mass index (BMI)?

Simply put, body mass index is a screening tool used to measure body fat based on weight and height. BMI was created by Adolphe Quetelet in 1832, and was deemed “body mass index” in 1972 by Ancel Keys. BMI is mainly used for adults, but is also used to measure body fat in kids and children. Because a child’s weight is always fluctuating, the body mass index may not be accurate until they reach adulthood. It doesn’t measure body fat directly; instead, it is correlated with measurements of body fat from skinfolds, underwater weighing, and X-ray absorptiometry.


How is your body mass index measured?


Your body mass index is measured using this formula: weight (kg) / [height (m)]2. Essentially, it is your weight (converted to kilograms) divided by your height (in meters) squared. You can also use: weight (lbs) x 703) /  height (inches) x height (inches). Essentially, this is your weight in pounds multiplied by 703, then divided by your height multiplied by your height again.

The end results should indicate whether you are underweight, normal (healthy weight), overweight, or obese.

  • If your result is below 18.5, you are considered underweight.

  • If your result is between 18.5-24.9, you are considered a normal (or healthy) weight.

  • If your result is between 25.0-29.9, you are considered overweight.

  • If your result is at 30.0 or above, you are considered obese.


You can also use a chart likes the one below.

Source: Pre-Diabetes

Source: Pre-Diabetes

Many of these results will vary depending on an individual’s height and weight.
 

Why is it important?

The body mass index is important because it gives crucial information on an individual’s body fat and weight. This is important information that can prevent obesity and other health conditions, such as: high blood pressure, high cholesterol, type 2 diabetes, and etc. It can also help individuals determine whether or not they have a weight problem.

However, the body mass index doesn’t apply to everyone. For example, some bodybuilders may be considered obese (due to the fact that muscle weighs more than fat). With that being said, the body mass index is a good indicator of healthy weight ranges and should be used as a way to determine whether or not your body is malnourished. A number that is too low could indicate malnourishment, while a number that is too high could indicate a risk of health problems. In order to maintain good health, the BMI should be used as a guide to healthy eating and exercise.