The BMI Index is a tool that was invented in the early 1800s. While there aren’t many health and fitness tools that were created in the eartly 1800s that we’re still using today just as they were, the BMI index is relatively unchanged in almost 200 years. It’s still a popular tool used to figure out if a person’s weight is healthy. The BMI simply compares your weight to your height and decides if you’re underweight, a normal weight, overweight or obese. Most of us can look in the mirror or notice whether or not we’re having to squeeze into our pants, and determine this without the use of numbers and calculations. But that doesn’t stop the BMI from being widely used by doctors, and worse, insurance companies.
Insurance companies frequently use a person’s BMI to determine if the person is a risk to insure. Health insurance costs can be higher for those who have a BMI in the overweight or obese range, and life insurance can be higher or it can be refused completely. While it’s within these companies’ rights to refuse to insure anyone, the use of the BMI index to make that determination represents flawed thinking, unless other factors are considered, too.
The BMI Index determines a person’s BMI by dividing their weight by their height squared (their height times itself). When kilograms and meters are converted into pounds and feet or inches, the formula changes very slightly, but the resulting BMI number is very close the number obtained by using kilograms and meters. For most people, the BMI Index is a decent measure of their weight in proportion to their height. But for some, it comes up with a label that’s far off.
Consider a championship bodybuilder. He’s one of the best in the world in the lightweight division, at 5′ 3″ and 154 pounds. The man is solid muscle, and he’s in amazing physical shape. The BMI Index says he’s overweight and needs to lose weight. When you take his height times itself and divide that into his weight, he comes up with a BMI of almost 27. The cut-off for normal weight is 24.9. Clearly, he’s not overweight, with barely an ounce of body fat anywhere. But an insurance company won’t care about that, they could refuse him insurance based on his ‘high-risk’ BMI.
Once you’ve used the formula to figure your number on the BMI Index, you can see where you rank as far as healthy weight. A person is underweight with BMI of 18.5 or below. The normal weight range is from 18.5 to 24.9. From 25 to 29.9 indicates that you’re overweight. And anyone with a BMI of 30 or over is considered obese. Try plugging in some professional athletes’ heights and weights, and see how many are classified obese with the BMI Index.
This makes it clear that while it’s a valuable tool, common sense, appearance and body fat must be considered along with the BMI Index to determine a person’s ideal weight.