Honest Blog

Why BMI is B.S.

“It ain’t what they call you, it’s what you answer to.” – W.C. Fields

Let me spell out a common scenario that many of you may be able to relate to. You’ve been working out at Honest for several months now and you’ve noticed significant changes. Your mood and stress level have improved, you’ve built muscle and stamina and you are no longer experiencing all those cumbersome symptoms that have been plaguing you for years! You follow the 80/20 rule and focus on clean eating and a nutrient rich diet, but you don’t turn down a sweet treat every once in a while (live your life people!). Thanks to your hard work and training at Honest you feel good…damn good!

Then it happens. You have your annual physical and find out that your BMI (Body Mass Index) indicates that you are overweight…wait, what??

According to the CDC (Center for Disease Control and Prevention), “A high BMI can be an indicator of high body fatness and having a low BMI can be an indicator of having too low body fatness”. But how can you be categorized as overweight when you feel so healthy? Suddenly your spirit is crushed and your accomplishments feel meager.

I have some advice for you. Close your eyes. Imagine you are holding that BMI in your hands. Now drop-kick it into the next century.

Let me explain why in many situations BMI is total B.S.

The Body Mass Index Formula was introduced in the early 19th century by a Belgian man named Lambert Adolphe Jacques Quetelet (say that 10x fast). He was a mathematician, not a physician, who was assisting the government by calculating a simple way to measure the degree of obesity of the general population.

What he came up with was taking a person’s weight in kilograms divided by the square of height in meters. To calculate that in pounds and inches you divide your weight in pounds by height in inches squared and multiply that by a conversion factor of 703.

The formula looks like this: weight (lb) / [height (in)]2 x 703

Example: Weight = 150 lbs, Height = 5’5” (65”)

Calculation: [150 ÷ (65)2] x 703 = 24.96

Go ahead and try yours now (you know you want to). I’ll give you a moment.

Below 18.5 is considered underweight, 18.5-24.9 is “normal” or healthy, 25-29.9 is overweight and 30 and above is obese.

Many of you may find that you have been shoved into the overweight or obese category and it just doesn’t make sense. While this formula can be reasonably accurate for the sedentary, inactive population, it can be completely incorrect when it comes to athletes and fit individuals. Quetelet himself said that his formula “could not and should not be used to indicate the level of ‘fatness’ of an individual”.

Here are a few glaring issues with the Body Mass Index.

It disregards waist size which is a much clearer indicator of obesity. Abdominal fat is a much stronger marker of disease risk as the fat surrounding the liver (and other abdominal organs) is metabolically active. It releases fatty acids and hormones that can ultimately lead to higher LDL, triglycerides and high blood pressure.

It cannot analyze the fat/muscle/bone ratio. Bone is much denser than muscle and it’s twice as dense as fat. By this measure it could be indicating that a person with strong bones, great muscle tone and low fat is overweight or even obese.

It attempts to plug people into 4 simple categories (underweight, ideal, overweight, obese) when it’s impossible to measure an individuals health in such simplistic terms. There is a huge gray area with many varying factors that contribute to that assessment.

It causes incorrect statistics. According to the most recent data released, Sept. 2015, more than two-thirds of adults were overweight or obese…that’s 68%! Now that you see the flaws in BMI measurements, how accurate do you think those statistics are? Here is a reputable study that shows how glaringly wrong BMI can be. Several people who were given “overweight” status based on their BMIs were in fact very healthy, while many others who were given an “ideal” status were found to be much less healthy based on further health measures.

It causes us to question medical advice and information. Is using the cheapest method really the best method to determine a patients health? Not to mention, many insurance policies charge higher premiums to those with a higher BMI (don’t get me started folks!).

When it’s all said and done, the BMI does serve a purpose and can be moderately accurate in sedentary populations. However, if you find that you are being forced into an “overweight” or “obese” box that doesn’t correspond to your healthy, active lifestyle? Drop-kick.

The best hassle-free ways to measure your health is to pay attention to these things:

  • Are your clothes fitting? (Do those jeans feel tighter than they did last week?)
  • Is your body telling you anything? (Fatigue? Headaches? Stomach pain? etc.)
  • Are your emotions all over the place? (Angry? Stressed? Depressed?)

It’s important to monitor your health. Just keep in mind that not all measures of doing so are created equal. Here’s to good health and to you!

Want to become your healthiest self with us at Honest? There’s no excuse because your first week is free! Sign up here.

Owner of Honest Training
Certified Personal Training w/ a specialization in corrective exercise and small group personal training
Fitness Fanatic
Pit Bull Mom
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