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The Problem with BMI

What is BMI?

health-and-fitness-motivation-by-elisaBMI or Body Mass Index is a frequently used to measure or quantify an individual’s body shape based on a correlation between that person’s height and weight. BMI was first created in the 19th century by a Belgian sociologist and mathematician Adolphe Quetelet as a means to measure populations with a predominantly sedentary lifestyle.

Today, BMI is used by doctors and other healthcare professionals as a means to objectively discuss weight problems instead of using terms such as “overweight”, “obese”, or “underweight”. However, more and more physicians and other healthcare professionals forget the intended purpose of BMI as a generic way of classifying a population and instead use it as means for diagnosis.

Misusing BMI:

Sounds unbelievable, doesn’t it? And yet it is increasingly true. About a year ago I went to visit one of a few dozen physicians from the “old country” that operate in my area. I thought that since this particular doctor had experience dealing with people from my region I could save some time on filling in the gaps about some of the common ailments and just get to being treated for the problem that was bothering me. What I didn’t expect is to come into the office get weighed in and to be told that I am overweight and need to lose a lot of weight.

bmi-chartAt this point, allow me to give you some back story. I am a runner with a love of bodybuilding. I am fit, I eat right, I have a fairly low body fat percentage, and high muscle mass. So, when the doctor whom I never met before, looked at me (I was wearing a hoody and loose pants) and told me that I really needed to start watching my weight and change my diet, I couldn’t help but laugh.

He, of course, asked me why I was laughing. I asked him why he thought I had a bad diet and was overweight. In turn, he turned my attention to the BMI chart and said that based on my height and weight, I was clearly overweight and that could be due to the fact that I am not eating right and not exercising regularly. Honestly, at that point all I wanted to do is get up, take my hoody off, flex my “guns” and walk out, but I refrained.

I nicely told him the following:

On a case to case bases, BMI alone is not a good indicator or predictor of health or body composition. For example, a man who is 6’ 3” with a weight of 210 pounds is considered overweight according to the BMI chart. However, the chart does not specify if the body fat percentage (BF) of the man in question. Sure, if the man has a BF of 30% or more he is overweight. However if you look at a man who weighs in at 210 and stands at 6’ 3” with a BF of 15%, I guarantee you, you wouldn’t be calling him even remotely overweight.

What is the Lesson to be Learned Here?

1970767_10152283371584394_2044580024_nBMI is a good way to analyze large samples of predominantly sedentary, average population, not as a way to discuss weight issues on an individual case by case bases.

You will hear fitness professionals tell their clients to stop concentrating on “the number on the scale”. This is partially the reason why. That number means absolutely nothing unless you pair it with measurements, accurate BF% measurements, and, of course, whether or not the client is trading their “fat pants” for the “skinny jeans”.

So, if anyone tells you that you are overweight / obese and you respectfully disagree, ask them why they think that. If the answer is that the BMI chart told them so, tell them to read this article and walk away. You should expose yourself to such willful ignorance and negativity.