You have probably heard it from every fitness guru that you know, the common question of what is your BMI or Body Mass Index?
Well, BMI is a screening tool to determine if your weight is proportioned to your height. With a simple formula, you will be able to know if you are slightly fat, obese, just the right weight or if you are underweight.
You might think that this tool is new and just riding the fitness vogue of this fitness craze era, but Body Mass Index or BMI formula has been around and was invented as early as the 18th century between 1830 and 1850 by the Belgian polymath Adolphe Quetelet. Only it was not made popular until the 1970’s.
BMI is computed by the formula weight / [height (in inches)]2 x 703. You weight should be expressed in pounds divided by your height in inches squared by the same and multiplied by 703. To illustrate, supposed you are 5 foot and five inches tall and weighs 150 pounds. Your BMI will be computed as follows:
- Your height will be converted to inches which is 65 inch.
- Square your height, 65 inches by 65 (65 x 65) and that will give you 4,225.
- Divide your weight, 150 pounds by 4,225 inches.
- That will give you a rounded BMI of 24.96.
But what does it mean? How can you interpret that figure? There is a table to figure whether you underweight, normal weight, overweight or just plainly fat or obese. But for the purpose of illustration, assuming above is your actual figure, you are considered to have a normal weight.
Here is the table:
- If your BMI is below 18.5, you are considered too thin or underweight.
- If your BMI is between 18.5 to 24.9 which is the case in the example, you being 24.96, you are considered to be in a normal weight. So you are okay.
- But if your BMI is between 25.0 and 29.9, you will be considered overweight.
- And if your BMI reaches 30.0 and above, you are considered obese or certified fat.
The index however has limitations in determining the true state of your physical proportion. It may inaccurately determine your physical condition on several factors. If you are elderly, your fat percentage may very well be greater than your body mass index.
On the other hand if you are an athlete, then your body fat percentage may be somewhat lower than your body mass index. Take for example the case of weightlifters and bodybuilders.
A weightlifter who is 6 foot tall may weigh well over 260 pounds. The body mass index chart will describe this person as severely obese or fat as the index reaches 30 on the BMI scale. But in fact, that bodybuilder may have a body fat percentage of less than half of that.
But in general the body mass index chart and formula is a relatively good guide of determining your body mass ratio or physical condition. It is not however a substitute of the physician’s opinion of your general well-being when he does his physical examination on you.
