Just a few years ago, not too many people were familiar with the term BMI. And you still might not be. But already, there is some backlash against the measurement of BMI and if it’s truly an accurate tally and predictor of your health and potential health risks.
New studies are finding that correlations between increased health problems and BMI might not be exactly as predicted, and the actual number score used in BMI is too generalized to always be accurate.
What is BMI?
BMI stands for Body Mass Index, and it consists of a fairly simple mathematical formula based on your height and your weight. The resulting number puts you into a broad category of classification. Under 18.5 is considered underweight, between 18.5 and 24.9 is considered normal, 25-29.9 is overweight and over 30 is obese.
To figure out your BMI number, you take your weight in pounds, and divide it by your height in inches squared. Multiply that number by 703 and presto, you have your BMI number.
Limitations of BMI
BMI is very generalized and can be applied to nearly anyone. That’s what makes it so attractive as a means of predictability, understanding and interpretation. The same system can be applied to everyone and therefore people can see where they lie in a scale in terms of their bodyweight and possible resulting negative consequences.
However, the generality of the formula is also the problem. By taking a simple calculation using body weight, there is no separation between muscle mass and fat. Therefore, you could be an extremely fit and muscular athlete and be considered as overweight or even obese, despite being a walking example of perfect health.
The formula can also only be applied to adults. Children and teenagers are still growing and their bodies are still filling out. Therefore, they may have put on weight that will eventually be spread out as they continue to grow.
Conversely, they may have sprouted up but haven’t put on any weight, and would be considered as dangerously underweight despite just going through a growing phase. So it’s important to never try to apply BMI to a child or teen.
Additionally, a BMI number can be misleading for a woman. Women, at the same height and body size as men, tend to have more slightly more fat. This is the genetic makeup of the female body, and should not be taken as being out of shape or unhealthy.
To Use BMI or Not to Use BMI?
So is BMI something you should even bother with? BMI is useful as a broad indicator of where you stand and potential health risks. It’s safe to say that you know your body. If you’re not particularly muscle bound, and you are coming up with a BMI in the upper 20’s or into the 30’s and beyond, than you should certainly consider yourself exposed to increased health risks.
However, one should not fret either of trying to fit into a perfectly classified “normal” range of weight for a particular height. Everyone’s body is different and the number can prove to be not very telling depending on your makeup.