What Is Body Composition?

What Is Body Composition?

Fitness enthusiasts are probably familiar with body composition. Doctors and health professionals often use the term to indicate how much fat, bone, and muscle there is in the human body. The body fat percentage is the most important aspect of it, as it can indicate the overall state of your health. 

In the following sections, you’ll learn more about this concept and how you can use it to your advantage when trying to get fit. You’ll discover how to gain a better insight into your wellness level and the steps you need to go through to achieve healthy body composition. 

Why Is Body Composition Important?

As we mentioned, body composition is essentially a breakdown of what you’re made of — fat mass, muscle mass, tissue, bone, and water. Undergoing body composition analysis means understanding your body on a deeper level than you’ll get with a classic body scale. However, with smart scales like Eros, you can track 13 crucial body metrics, including body weight, body fat, bone mass, muscle, basal metabolic rate (BMR), and more.

People often confuse body mass index (BMI) with body composition, but the two terms are quite different. Health professionals use BMI to learn your weight status, that is, the ratio of your weight to your height. This information is simply insufficient to get a clear picture of someone’s health condition. Therefore, BMI is more helpful if doctors try to determine if a person has an eating disorder or is overweight.  

On the other hand, body composition helps you understand your body weight much better. Most individuals fall into one of the following categories:

  • Balanced body composition — If you meet these criteria, your weight, body fat percentage, and muscle mass are all at an equal level. 
  • High muscle mass/low body fat — People in this group may carry an excessive weight for their height, but it’s due to the greater percentage of muscle mass. 
  • Low muscle mass/high body fat — Individuals in this category may have a healthy weight, but their body fat percentage is high, and their muscle mass is low. 

What Is a Healthy Body Composition?

Healthy body composition is not a fixed formula, as it depends on several different factors, including your fitness level, metabolism, gender, and age. A healthy body should definitely contain a higher proportion of fat-free mass and a low percentage of body fat. Having enough skeletal muscle mass is crucial for leading a healthy life, as it can be of assistance in protecting you against chronic diseases like diabetes.

As you age, your body composition will change — that is, body fat percentage will increase, and the lean mass ratio will decrease. What’s more, females naturally have and require more body fat, which is normally stored in the waist and thigh area. 

Of course, let’s not forget about genetics and hormones because they can hugely impact our body composition. We should also include sleep patterns, frequency of physical activity, and alcohol consumption as other important factors of our overall health status. 

How to Measure Body Composition

There are several different ways to assess one’s body composition. Each test varies in method and accuracy.

Bioelectrical Impedance Analysis (BIA)

BIA relies on low electrical currents that estimate the levels of fat-free mass. As electricity travels through water and since many of our organs contain a certain amount of water, the current flow will depend on the tissue type. Therefore, its flow becomes less interrupted if you have lean muscle. Remember that hydration levels can also impact its results.

Multiple devices rely on bioelectrical impedance analysis. One is the Eros Smart Body Scale, which uses this technology to analyze and calculate your body composition values. You can keep track of your progress on its free app, and the results you’ll get are within +/- 3% of DEXA scans result standard.

Skinfold Tests

As one of the oldest ways to measure the amount of body fat, the findings of skinfold tests tend to be unreliable. Skinfold calipers are used to pinch the specific areas of your body through either 3-point or 7-point measurements. These are then combined with your age and gender to get the final results. However, since people store fat in different places, the findings may not be that accurate. 

Hydrostatic (Underwater) Weighing

This test uses your body weight in water and on land and water displacement to determine your body composition. If you still remember your physics lessons, this method may ring a bell as it relies on Archimedes' principle. As muscle is denser than fat, it will sink. Following the same logic, the person with more muscle mass will weigh more underwater. 

Air Displacement BodPod

This method works similarly to water displacement, except that you’ll need to enter an air-controlled chamber instead. The pod utilizes a mechanical diaphragm to generate volume changes and measure pressure responses. Your height, weight, age, and gender will be taken beforehand. As your body weight determines your mass, volume is calculated based on the displacement in the pod. 


This scan is the most accurate one in the industry at the moment. DEXA scan relies on X-ray technology to provide a detailed assessment of your body composition, including where fat and muscle are stored. It can even tell the difference between visceral and subcutaneous fat. Its margin error is quite impressive, coming in at 1.6%.

Final Thoughts

As you can see, knowing the exact state of your body composition can be crucial in determining the overall state of your fitness. There are several ways to check it, with varying degrees of accuracy. However, whichever method you choose will bring you one step closer to living in a healthier body. Once you know where you stand, you can easily make adjustments to become the best version of yourself.