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BMI, Scale, Measuring Tapes...which to trust!

Updated: Sep 21, 2023

BMI is not the only measure of health: fat vs. function.

Many or most of us truly understand the internal struggle of being a lifelong yoyo dieter, someone who would love to be a few pounds lighter, fit into a smaller pant size, have a flatter stomach, etc. We all understand the magnetic strength of the scale and how obsessive we can get over the number on the screen. However, the ongoing trend among medical professionals to use body mass index (BMI) over the scale's number, as a primary indicator of health and fitness, is not capturing the whole picture either. 

BMI is a simple measure of your height to weight ratio, calculated by taking your weight in kilograms and dividing it by your height in meters squared (kg/m²).  What it can offer is a basic idea of whether you fit into a normal weight category. Since the measures are easy to get, BMI offers a simple shorthand for busy professionals to make quick decisions. What BMI does not take into consideration is your muscle mass, overall body composition (proportion of fat, muscle mass, bone density, etc.) or any other useful health markers. 

There are many informal but just as valuable health markers that we can easily measure ourselves. For example:

  • Being able to walk up a flight of stairs without getting winded?

  • Getting up off the floor without help?

  • Completing regular activity (3-5x/week for an accumulate 150 minutes/week)?

  • Ability to lift your groceries?

  • Walking up or down stairs without pain?

  • Reaching over your head? 

  • Maintaining blood pressure within normal healthy range?

  • Being able to do things that matter to you without being limited by your body?​

The reality is, being substantially overweight can cause an individual to have trouble with many of the scenarios above. However, many people who technically fall into the overweight and obese range on a BMI scale have no problems with most or all of those same things. So the issue becomes: What should we consider as appropriate health markers? The number on the scale or how well you can complete functional activities?

This is in no way an argument for being obese. There are huge risk factors associated with carrying 40+ extra pounds on your frame, from increased load on your joints to a greater risk of diabetes and other diseases. This instead is a discussion for people dealing with the frustration of being within a healthy range of function and body composition, but cannot see it reflected through BMI or a number on the scale. 

There are better metrics on which to measure your health, fitness, and wellness are functional abilities and goals. Keep your focus on functional fun tasks that will make a difference in you everyday life, like...

+ If your knees hurt every time you squat to pick something up or go up and down stairs, then working to build strength and stability around the joint to prevent the pain is something tangible and attainable. Not to mention the huge boost to your quality of life when moving around your house gets easier and less painful.

+ If walking a few blocks to the grocery store is out of the question because you get winded or can’t carry your groceries home, then working to increase your cardiovascular ability is huge. 

If you’re already someone who doesn’t have to think about taking your dog out for an hour long walk, then maybe it’s the ability to hike up Mount Finlayson without getting rubber legs by the time you get to the bare rocks near the top that would be a better metric for your fitness. Or increasing your deadlift personal best, or lowering your 500m split on the rowing ergometer, or running a 10k in 45 minutes or less, etc. 

The point is, the number on the scale and BMI are not valid singular measures of  health and fitness and there are better indicators of your overall health for you and your health professionals to measure. Many athletes are considered to be overweight by definition of their BMI simply because their muscle mass increases their overall density for their height. All of this is not to ignore that losing a substantial amount of weight is a huge accomplishment too, it takes a huge amount of work, discipline, and drive (and even more-so to maintain that accomplishment). It is simply to acknowledge that there is an ongoing excess of focus put into a number on the scale, instead of on the ability of the individual to live and enjoy their life. BMI and weight loss is one part of a broad spectrum that make up one's health.

So, stay strong, stay active and try to not let a number define you! ​​Thank you for reading and we'd love to hear your thoughts in the discussion below!

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