What’s Your Number?

What’s Your Number?

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Do you remember your first encounter with height/weight tables? Like most, mine was in high school; I recall looking at the height and weight tables in health class and fearing that I would be force-fed by the PE teacher. The problem with any of the standard yardsticks that have been used to establish what is average, normal and, more importantly healthy, is that they cannot assess, in total, what may be the ideal weight and configuration for your body.

Height and weight tables have been used since the 1940s to give insurance companies statistical information about their clients. This information was then used to project mortality rates. This is important for two reasons. First, we need to recognize that these tables weren’t created to guide us in our health maintenance; they were devised to predict our demise.

Secondly, they did not address other factors such as a person’s frame size. The charts have improved over time, and at some point, the CDC (Center for Disease Control) added another tool, the Body Mass Index (BMI), as another way of determining appropriate and healthy body size.

There's a one-stop-shopping Web site for all of these charts and comparisons at www.halls.md/index.htm. The chart below is from this site. If you visit it, read what Dr. Halls writes about the imperfections of all these measurements. He has a great deal to say about the BMI. But for now, let’s look at the height and weight charts.

Height & Weight Table For Women:
This chart above is great (I may be prejudiced because it tells me that I can have dessert tonight), but how do you know for sure what your frame size is? To calculate your “frame size” Metropolitan Life, the insurance company credited with creating the original charts, came up with this method:
1) Bend forearm upward at a 90 degree angle.
2) Keep fingers straight and turn the inside of your wrist toward your body.
3) Place thumb and index finger of other hand on the two prominent bones on either side of the elbow.
4) Measure space between your fingers on a ruler. (A physician would use a caliper.)
5) Compare with tables below listing elbow measurements for medium-framed men and women. Measurements lower than those listed indicate small frame. Higher measurements indicate large frame.

The BMI formula was developed by Belgium statistician Adolphe Quelet (1796-1874), and was known as the Quetelet Index. BMI is also referred to as "body mass indicator" and is an internationally used measure of obesity.

I first heard about the BMI a few years ago, when a bit of a fuss was made about beauty pageant contestants and their freakishly low BMIs. Based purely on those numbers, commentators deemed nearly all of the contestants dangerously thin. They even went on to say that it confirmed the American ideal as “rail thin” because the BMI had consistently descended over the last 40 years.

The BMI is a reliable indicator of total body fat, which is related to the risk of disease and death. The problem with this particular measurement, however, is that it only calculates mass, in other words how much space a human being occupies. It in no way measures what inhabits that space. Given that a bulky body could be filled to capacity with muscle or fat and still have the same BMI, it simply cannot give us a complete or even accurate picture of an individual’s true physical configuration.

The BMI is useful, however, when it is used in conjunction with other charts, measurements and additional information.

To calculate your BMI you can use the Imperial BMI formula which accepts weight measurements in pounds and height measurements in either inches or feet.

If you prefer a bit of technological assistance in the calculation, the National Heart, Lung and Blood Institute has a great BMI calculator: www.nhlbisupport.com/bmi , as does www.halls.md/index.htm. This Web site combines the BMI charts (below) with quite a bit of insight.

When it comes to the use of BMI he makes several points including:
“In adults, using a BMI threshold of 25 as the definition of 'overweight' will classify over half of the American population as overweight. Thus, it is entirely possible to have a weight percentile at the 50th percentile, and be considered overweight. You could be average weight and overweight at the same time.”

Many health experts have started pairing waistlines measurements with BMI to view the equation of the body from yet another angle. Since body fat that accumulates around the waistline has become an accurate indicator of several specific health risks, this numerical combination can be helpful for certain individuals. The bottom line is that all of these tools are much like your bathroom scale, in that they offer fair, but incomplete, gauge in determining where you stand in creating and maintaining a healthy body. When used together, however, they will render a complete assessment.