Fitness Column: Body Mass Index-Helpful or Useless?

Fitness Column
Body Mass Index: Helpful or Useless

Body Mass Index (BMI) is a commonly used tool to estimate the amount of fat on a person’s body. For decades the term has been used by health professionals and trainers when assessing an individual’s fitness level. A person’s BMI depends on two things: their height and their weight.

Is the measurement an accurate evaluation of someone’s health? Often, it is not. While BMI can give you an estimation of your level of health and fitness, since BMI takes into account only height and weight, many will not get a true assessment from this number.

For instance, let’s say a man is 6’1” tall, weighs 190 pounds and has 10 percent body fat. His BMI would put him in the overweight range. For him to be in the mid-normal range of BMI, he should weigh only 163 pounds, meaning he would need to lose 27 pounds, but weighing 190 pounds and having 10 percent body fat means that he has only 19 pounds of fat on his body to begin with.

I have seen cases of BMI numbers being extremely misleading. Many of the competitors in the local bodybuilding competition we hosted would be classified as obese because of their high BMI. Because BMI takes into account only height and weight, and not muscle mass or body fat percentage, they would be seen as extremely unfit which, of course, is not the case.

To get a truer estimation of your level of heath and fitness, consider having your body fat tested. Avoid testing with a scale or hand held device as they are notoriously inaccurate. Bodypod or water immersion testing facilities can be found in larger cities, but are costly and time consuming.

Consider having a skinfold caliper body fat test done. They are quite accurate when conducted properly. If you’d like, contact me at the Fitness Center. The tests are free and only take a few minutes.

Or you can do what our good friend Bill Hudson has always said to do if you want to know if you have too much body fat. Take off your clothes and jump up and down in front of the mirror. Your answer will be right in front of you.

Kent Pegg is a certified personal trainer and owner of the Los Alamos Fitness Center. Direct questions about the information in this column to Pegg at 505.662.5232.