June 16, 2024


Define Beauty Yourself

Why body composition matters for health and fitness

Being aware of your body composition can help determine your health’s overall state. Sometimes, despite appearing to be healthy on the outside and weighing normal weight on the scale, a person may still have an unhealthy or altered body composition.

It is vital for health and wellness to have a healthy balance of fat and muscle. There is scientific evidence showing that healthy body composition can increase lifespan as it reduces the risk of heart disease, certain types of cancer, type 2 diabetes and insulin resistance, increases energy levels and enhances self-esteem [1]. 

What is body composition?

The ideal healthy body composition has a decreased percentage of body fat and an increased percentage of non-fat mass, including bones, muscle and organs. Your body composition can help assess your overall health and fitness level.

Body composition refers to a universal term used in the health and fitness industry. Health professionals use body composition to identify what percentage of the body weight is fat and find out one’s health level. 

Moreover, determining your body composition is significant as other people may have the same height and weight as you; however, they might have more body fat and lesser muscle mass, which could lead to various health issues. 

The weighing scale can’t show the amount of body fat and muscle mass in your body, but body composition can help in identifying them. Weighing scales can be misleading as the body weight consists of other factors affecting weight, such as muscle, fat and bone added all together. 

A healthy body composition involves less fat and more muscle mass, as too much body fat can further lead to greater risks of developing cancer, diabetes, heart disease and other health problems.

As people age, the body begins to lose muscle mass, and, as a result, the body gains a higher fat percentage. A body scan also gives an accurate depiction of bone density. In addition, your bone health is also important in preventing bone loss over the years to prevent the development of osteoporosis.

Beyond BMI: Why body composition matters for health and fitness
Photograph: DC_Studio/Envato

Body mass index (BMI) and body composition

With the growing number of obesity in children and adults, understanding your body fat levels may help with your short-term and long-term health state. 

Body weight can be tricky. For instance, two individuals of similar gender and body weights may look entirely different from each other as they have different body compositions. The best explanation for the situation mentioned is because of body composition and growth, which are two key components of health in individuals and populations. 

Body Mass Index (BMI) refers to a manual measurement using height and weight only. However, there is criticism of BMI as a measure.

Body Mass Index (BMI) refers to a manual measurement using height and weight only. There is criticism on BMI in the health industry for its reliability as a health measure, due to its lack of consideration of body shape and weight distribution in the body [2].

Over the years, the body has become more susceptible to storing fat due to decreased metabolism and hormonal changes. Resting Metabolism lowers proportionally as the body fat percentage increases.

You can use BMI to see if you’re overweight, but it doesn’t measure body fat. It only shows the ratio of your weight to your height, so it’s not a good tool for figuring out if you’re healthy.

Usually, having a high BMI of more than 30 indicates obesity, meaning you have a higher body fat percentage. With this BMI, you are at risk for fatal health problems, such as hypertension or high blood pressure, osteoarthritis, stroke or type 2 diabetes. 

Medical professionals use BMI to calculate the height and weight of a person. From there, the results may indicate underweight, normal weight, overweight or obese. Despite its link to body fat percentage, BMI doesn’t give a full picture of what’s inside.

Moreover, BMI is more helpful as a global index for nutrition rather than a health indicator. It is useful in determining if a person is overweight or obese or has an eating disorder. If you’re trying to figure out your body composition, it may not help.

Metabolic age and chronological age

One good way to measure one’s health is by calculating their metabolic age. The Basal Metabolic Rate should be compared with the chronological age group to identify whether the metabolic age is lower or higher than the actual age. 

In explaining the measurement results, it suggests that if the metabolic age is lower than the actual age, the person has overall functional fitness and healthy metabolic activity 

Body fat

Body fat needs less energy than lean muscle because it is much more metabolically active; hence, more energy expenditure can help keep homeostasis. 

The body is made up of water, protein, minerals and fats. There are two kinds of fats in the body, which are essential in keeping the body functioning, such as: 

  • Non-fat mass – or also known as essential fat, can be found in bones, liver, kidneys, intestines and muscles. Organ fats are required for the body to function optimally. ‌
  • Fat mass – or also known as stored fat, can be found in the adipose tissue. Fat mass can be used as energy for the body as it insulates and cushions the body. This type of fat mass borders your organs and is found under your skin.

Having excessive stored fat is harmful to your health and can lead to chronic diseases and medical conditions, primarily the following:

  • Diabetes
  • Fatigue
  • Heart failure
  • Obesity

By knowing your body composition, you can monitor the shift in your body fat and muscle mass. When you exercise regularly, but your weight stays the same on the scale, your internal body composition might have changed. 

Benefits of having a healthy body composition

Reducing your overall amount of body fat can improve your body composition and quality of life and may extend your lifespan.

Some health benefits of having a good body composition are the following: 

  • Get a normal blood pressure level
  • Have an improved quality of sleep
  • Gain self-confidence and relieve mood
  • Better breathing, respiration and lung function
  • High energy and endurance throughout the day
  • Lowered pain in joints, hips and lower back
  • Enhanced blood circulation, which leads to decreased risk for heart disease
  • Improved glucose tolerance and insulin sensitivity
  • Higher fertility rates and decrease the risk for pregnancy-related complications

Determining body composition

There are several ways on how you can assess and determine your body composition, such as the following: 

Skin calipers – it is used to measure the skinfold thickness of a person, particularly the areas where stored fat is usually found. When completed with an effective technique, skin calipers can be very precise, but human error can trigger many fluctuations.

A body pod – this type of machine measures the amount of air your body displaces. It is the easiest option compared with underwater weighing as it usually takes less time. ‌

Underwater weighing – when the body is underwater, your lean tissue sinks and fat floats. Your underwater weight aids in estimating how much fat mass your body has. This method is accurate in finding body composition, but it requires special equipment. 

Dual X-ray Absorptiometry (DXA) scan – the DXA scan uses low-level X-rays to determine the amount of body fat, muscle and bone in your body. It is a quick method and also involves bone in the assessment.

Your overall body composition can be identified by using a DXA scan and body composition analysis. The DXA total body composition scan can provide a ratio of body fat against fat-free mass. Plus, it is a great indicator of any medical issues you may have and health changes to start [3]. 

Bioelectrical impedance – this type of analysis can send electrical currents throughout the body. Then, it measures the speed at which it travels. 

Bioelectrical impedance is considered to be the cheapest method of measuring your body fat, next to skin calipers. In terms of accuracy, this method’s precision greatly depends on many factors [4]. 

How to improve body composition?

Resistance exercise can preserve and build lean muscle mass and burns calories to improve body composition. The following are the types of equipment or classes for resistance training that you may try: 

  • Aquatics
  • Calisthenics
  • Free weights
  • Machine weights
  • Resistance bands
  • Yoga
Beyond BMI: Why body composition matters for health and fitness

Cardiovascular exercises can also put lean muscle to work; therefore, can cause calorie burn. There are all kinds of cardiovascular exercise, also known as aerobic exercise, to try to improve body composition, such as: 

  • Basketball
  • Cross-country skiing
  • Cycling
  • Dancing
  • Rowing
  • Running
  • Swimming/Aquatics
  • Tennis/racquetball
  • Walking


Knowing your body composition can help determine your health’s overall state, and BMI may not be the best method to help you measure it. Also, weighing scales can be misleading as the body weight consists of other factors affecting weight, such as muscle, fat and bone added all together. 

There are several methods how to determine your body composition, such as skin calipers, a body pod, underwater weighing, Dual X-ray Absorptiometry (DXA) scan and bioelectrical impedance. 

You must reduce your overall amount of body fat to improve your body composition and quality of life and may extend your longevity. 

[1] https://academic.oup.com/ageing/article/41/5/677/47347#
[2] https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm 
[3] https://www.nhs.uk/conditions/dexa-scan/ 
[4] https://www.unm.edu/~lkravitz/Article%20folder/underbodycomp.html 

The information included in this article is for informational purposes only. The purpose of this webpage is to promote broad consumer understanding and knowledge of various health topics. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.