# Is the Body Mass Index a Load of Hooey?

Body mass index (BMI) has been riding high as the “fat measurement du jour” for quite a while now. Everyone knows that your BMI is the key to measuring just how overweight you are. It’s got everything: It sounds scientific, it’s easy to calculate, and it’s used everywhere. Additionally, you hear about it in the news, on TV, and in magazines. It’s the one-size-fits-all measurement that anyone can learn in minutes.

The formula to determine BMI is simple enough. Calculate BMI by dividing weight in pounds (lbs) by height in inches (in) squared and multiplying by a conversion factor of 703.

Example: Weight = 150 lbs, Height = 5’5″ (65″)

Calculation: [150 ÷ (65)2] x 703 = 24.96

The 703 is for converting the formula from its original metric version. The Centers for Disease Control in Atlanta have found that a BMI of 18.5 to 24.9 is ideal; anything from 25 to 29 is overweight; and 30 or above is obese. This seems like a decent standard doesn’t it? If the government using it, then it must be a good measurement for obesity, right?

Not so fast. More and more health experts are coming forward to say that your BMI isn’t worth the calculator you used to determine it. Here are some of the most compelling reasons that we should not be using the BMI to determine our level of health and fitness.

To begin, we need to understand that the BMI formula was invented to measure the general population-not individual people. Lambert Adolphe Jacques Quetelet, the guy who came up with the formula, was a mathematician, not a doctor. Additionally, his system is a formula designed to fit the data that had already been collected. It was never intended as a means for classifying body fat.

BMI makes no allowances for bone density, muscle tone, or the amount of fat in your body. A health-conscious, well-built athlete can find themselves classified as obese using this scale. Quite simply, it just doesn’t account for individual body types or weight from muscle vs. fat.

The underlying logic is based on statistical averages. Statistical averages are why experts say that the average American family has 1.86 children, yet we don’t see many specialty clothing stores for 86%ers. Statistics can be very useful when applied to groups, but they often break down when discussing an individual.

It’s easy to see why we love the BMI so much. With a few calculations, you can arrive at a single, scientific-sounding answer like 18.5. BMI seems like a legitimate scientific measurement. It also creates a distinct category for everyone. You can be classified as underweight, ideal, overweight and obese. Nice and tidy. We like that in a measurement system. Unfortunately, the index doesn’t take into account fitness level or anything else, really. It’s great for statistics, but bad for individuals.