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MYTH OR FACT? BMI & THE SCALE

Written by Otho Nash, Jr.

Many people come to the gym seeking to lose weight for one reason or another, and some of them may hire a personal trainer for help in reaching their goals. Someone may be looking to lose 100 lbs in anticipation for their 50th birthday in the following year. A woman may be looking to lose 50 lbs for her relative or best friend’s wedding in 6 months. A guy may be looking to lose 20-30 lbs in getting rid of his Dad bod for the upcoming summer. When it comes to looking at our progress and reaching our fitness goals, many myths and facts arise between BMI and the scale. Let’s take a look at both: 

Myth or Fact: BMI is a perfect indicator in determining an individual’s fitness level.   

Myth. BMI (body mass index) charts have been used by healthcare professionals since the 1980s as a way to help individuals live healthier lives. It is an estimate of body fat and it classifies individuals into five categories based on height and weight calculations: underweight, normal, overweight, obese and severely obese (Portman and Ivy, 17-18). Two separate BMI charts are used for men and women, ranging in multiple height and weight collaborations which determine where an individual is currently and where he or she should be based on those collaborations. Using a BMI chart will also indicate if an individual is at risk for chronic diseases such as heart disease, high blood pressure, type 2 diabetes, stroke, cancer, etc. 

height and weight graph for the human body

However, a football player who is 6’4” and weighs 230 lbs is considered to be overweight. Likewise for people within the general population whose BMIs lie outside of the normal range (18-24.9). According to BMI results and doctors alike, overweight and even underweight individuals are considered to be unfit/unhealthy, but it is highly possible for these individuals to have great fitness levels. On the other hand, an individual whose BMI is within the normal range can be considered unfit/unhealthy. The fact that we’re not looking at the lean muscle mass to body fat percentage ratio plays a major role into how healthy and fit an individual is.   

Myth or Fact:  How many pounds we lose (or gain) on the weight scale shows if we are making progress (or not) in our fitness journey.  

Myth. Looking at the pounds on the weight scale is a good way to tell us if we are making progress, which could encourage us to continue reaching our fitness goals. At the same time, we could easily become discouraged and decide to discontinue our fitness journey. When we get on the scale, regardless of whether we are looking to lose or gain weight, the pounds on the scale do not tell the big story. We should be looking more so at our muscle mass and body fat percentage. This can depend on the type of scale used, as modern scales today can measure not only total weight but also total body composition factors such as lean muscle mass and body fat percentage.   

There are other factors that “weigh” into our progress on the weight scale. When it is shown that an individual has gained weight (especially from strength training) after starting their fitness journey, it is likely due to gaining muscle mass instead of fat mass. Pound per pound, muscle mass and fat mass weigh the same. The main difference between the two is that muscle mass is more solid than fat mass (Davis et al.). Other factors that we should look at besides the scale include noticing an increase in our energy levels throughout the day, how much more sleep we are getting at night, any differences in the fit of our clothing, and overall physique, etc.  

So, the question is, should we depend on BMI or the scale as evidence of reaching our fitness goals?

The answer is neither.

As previously stated, it depends on the type of scale used, as every scale is different. In my opinion, when it comes to solely looking at weight in pounds, the physician’s scale (balance beam scale) is the most accurate scale as opposed to a digital or mechanical bathroom scale. However, there are more modern scales that can be used for home use such as the Triomph Precision Body Fat Scale and the Withings Body+ Scale. These two scales, among others, use bioelectrical impedance analysis (BIA) to measure several factors of body composition including muscle mass, body fat percentage, and water intake levels (Link and Hildreth). Other devices that can be used for measuring body composition include the Dual-Energy X-ray Absorptiometry (DEXA) Scan, Bod Pod, or the In-Body Scan. These devices are more expensive, are used at medical offices, universities (often for research), and certain fitness or sports facilities, and can range from 3-10 minutes in finding an analysis. Another device, the skinfold caliper, is an accurate yet inexpensive method for measuring body composition.

To save frustration, I would not recommend getting on the scale or using any body composition method on a daily basis. Noticing other physical factors such as our daily energy levels, sleeping patterns, and an improved physique should determine how much progress we are making, as opposed to focusing on where our fitness level is according to the BMI chart.  

No matter if you get instant or long-term results, one of our personal trainers will create a diversified workout program for you with plenty of variety! Set up your first FREE training session at Austin Simply Fit today.

 

Works Cited

Davis, Jeanie L., et al. “Don’t Fall for Fitness Myths.” Don’t Fall for Fitness Myths, WebMD, 30 April 2004, https://www.webmd.com/fitness-exercise/news/20030731/dont-fall-for-fitness-myths. Accessed 10 October 2021.

Link, Rachel, and Danielle Hildreth. “The 12 Best Body Fat Scales of 2021.” The 12 Best Body Fat Scales of 2021, Healthline, 14 January 2021, https://www.healthline.com/nutrition/best-body-fat-scale#A-quick-look-at-the-best-body-fat-scales. Accessed 10 October 2021.

Portman, Robert, and John Ivy. Hardwired for Fitness. Laguna Beach, CA, Basic Health Publications, 2011.