Body Composition: What does it mean? How can you measure it? And, what can you learn?

Your doctor may have mentioned a body composition test at a recent physical, or maybe the trainer at the gym started waxing poetic about how working out in a specific way will change your body composition. If you’re anything like me, your eyes glaze over, a smile lands on your face and you nod your way through the conversation. All the while, deep down, you’re thinking: “What are they talking about? What does body composition actually mean? How do I find out what mine is?” Well, the good news is, if that sounds like you, you’re definitely not alone. 

Many people don’t truly know what body composition means or why understanding how and where they, personally, store fat, can help them make better health and wellness choices.

Think of your body composition as a blueprint for your health. Everyone carries mass differently so understanding what makes you unique can help you better work with your body, instead of against it. Body composition is, at its most basic, a breakdown of all of the elements of your body: bones, muscles, fat, organs etc. By pulling all of these pieces of your body apart, you can finally see what’s happening “under the hood”; it will tell you if you need to replace the oil, change a filter, tighten a belt or upgrade the motor. This information can be used to make better, more accurate, decisions about how you manage your health. 

Body Composition Defined 

A body composition analysis gives you a quick snapshot of your health by breaking apart your body into two types of mass: body fat and fat-free mass. 

  • Body fat - this refers to all the fat in your body, such as the fat around your organs or abdomen (visceral) and the “jiggly” fat you see just under your skin (subcutaneous). While some amount of fat is essential for your health, other fat, like visceral, is non-essential and having it in excess can increase your susceptibility to chronic illness and health complications. 

  • Fat-free - this covers all the things in your body that aren't fat, including muscles, bones, water (both intracellular and extracellular), minerals, proteins, organs, and other tissues. 

While the (often dreaded) act of stepping on a standard bathroom scale will provide an easy metric for monitoring your weight over time, that number alone is just that, a number, one that doesn’t accurately tell the story of your health. It’s like looking at the cover of the book and thinking you know the complexities of the plot lines inside.

Body mass index (BMI), another frequently used measurement of health, generates a value based on height and weight that broadly categorizes you as being underweight, normal, overweight or obese. The equation is far from perfect, and can be misleading. In fact, it’s entirely possible to be a “healthy weight” or to have a body mass index (BMI) in the “healthy range” but to still be at risk for disease and chronic illness because of the way the mass in your body is distributed. Keep in mind, while muscle and fat weigh the same, one pound of muscle takes up far less space than one pound of fat. So, two people who are shaped completely differently can have the same BMI and one could be at risk for disease while the other could be completely healthy.

By breaking the body down to its core components through a full body composition analysis, you can accurately measure and track changes in muscle mass, fat mass, and body fat percentage over time which can help you identify the areas you need to work on to lower your risk of disease and improve your overall health. 

Let’s revisit my car analogy from earlier. Say you have a car that has just stopped working. The engine won’t turn over, and the only other clue you have is the black smoke pouring out from under the hood. A mechanic wouldn’t just look at the exterior of the car, he would pop the hood and get stuck into the inner workings of the vehicle. The same applies to your health. How can you find a solution or have the information necessary to make a change based on data like your steps or BMI alone? It’s simple; you can’t. 

How to Measure Your Body Composition

Below are a few of the methods used for measuring your body composition

Bioelectrical Impedance Analysis (BIA)

This technique uses body fat and lean muscle mass as the basis for measurement by way of either a handheld device or BIA scale. Small electric currents are sent through the body and because water, fat, and lean tissue mass interact with the currents differently the devices can accurately assess the distribution of your mass. 

Skinfold Measurements 

Skinfold Calipers

Skinfold Calipers

Skinfold measurements, done by pinching the skin with calipers in seven different areas on the body, can provide a quick and relatively accurate estimate of body fat that can be compared to others of similar age and gender. This technique, while quick and requiring very little equipment, does not paint a complete picture of the different types of fat or how and where your body is storing it.  

DEXA Scan

Another way to measure body composition is with a DEXA scan. DEXA is short for a dual x-ray absorptiometry scan - thank goodness for acronyms! - that uses a high-precision x-ray, to measure two compositions in the body: bone and soft tissue mass, allowing you to get an in-depth and accurate view of your body including your body fat percentage, bone density, and muscle mass. While the word xray causes many people to question the safety of a scan like this, it has been shown that the amount of radiation used in a DEXA scan is extremely low, equal to less than two days-worth of natural background radiation, so you shouldn’t be concerned about any negative effects on your health.

Bod Pod Body Composition Test 

A Bod Pod test is another quick and accurate way to measure body composition. It can detect even the smallest of changes in body fat and lean mass. The Bod Pod uses air displacement technology to determine your body composition. The test takes place in a Bod Pod cabin, that kind of looks like a little rocket ship, and lasts about five minutes.  

Final Thoughts: How You Can Make the Most Out of Your Body Composition  

Taking control of your health and making long-term and sustainable health changes is tough. Fitness trackers and watches offer the user data based on algorithms that relies on averages not entirely unique to who you are as an individual. As helpful as these wearables can be in providing daily metrics, monitoring the number of steps you take or hours you sleep each night can’t tell you the real reason why that trendy new diet just won’t work for you or why you can’t seem to build muscle mass no matter how often you go to the gym.

Having a full understanding of your body composition, by getting it properly measured, will give you personalized insights that take the guesswork out of your health and fitness goal setting.