In a world where image is all-important, many of us turn to the gym to hone our bodies and lose that extra weight. But, should losing weight be our main objective in pursuing health and fitness?

Here we look at the various types of body fat and consider what is important for a healthy body.

Why Is Body Composition Important To Measure?

Your body composition refers to the body fat percentage of your total tissue mass. The human body comprises muscle, bone, fat and water. In an unhealthy body, the body fat percentage is high or very high.

It is important to be aware of your body composition because it is a measure of your overall health and fitness. Your bathroom scales can tell you your body weight but they can not tell you your body fat percentage.

When you learn about your body composition, knowing where your body fat has accumulated by measuring body fat percentage can instruct your nutritional needs analysis to aid losing body fat in the future.

DEXA Scanner

Body Fat Percentage

Your body fat percentage is measured against your muscle mass and other tissue mass. Body fat is an essential energy store but should not be excessive. A healthy weight should be a balance of fat and muscle mass.

If the tests assessing body composition show that you have a high body fat percentage, you need to take action to improve your body composition. This will help you to lose weight by attaining a healthier body composition and reducing your risk of cardiovascular disease.

When the health professionals on your healthcare team analyse your body fat composition, they can advise on an exercise plan to reduce your stored fat by promoting muscle growth and improving your overall muscle mass, because increasing your lean muscle mass will help you to minimise the health problems associated with heart disease.

Why is Body Composition Important?

Primarily, body composition is a measure of your overall health. There are a number of types of body fat and they serve different purposes.

Excess Body Fat


There are two main types of body fat:

  1. Subcutaneous fat: is the layer of fat under your skin which serves to insulate and protect the body.
  2. Visceral fat: is sometimes known as organ fat as it surrounds and cushions the internal organs.

As well as providing essential insulation, body fat provides us with energy. It also carries fat-soluble minerals needed for making our hormones and for building cell membranes. For this reason, this type of fat is essential fat.


Body fat percentage is the ratio of fat to your total body weight. A number of factors influence your body fat percentage including:

  • gender
  • fitness level
  • lifestyle

Athletes tend to have lower body fat percentages. But athletic performance drops and the immune system suffers when body fat percentages fall too low.

Conversely, if the body fat percentage gets too high, the risk factor for chronic illness escalates. Diabetes, high blood pressure and cardiovascular problems become very real dangers.

A healthy body fat percentage ranges between 10% and 13%.

Healthcare Professional

What is a Healthy Body Composition?

There are many factors involved in determining body composition. Age, gender, fitness level and body weight are the main considerations.

Taking a measure of your body composition should be a regular habit, as research has shown that the more body fat we carry, the greater our risk for developing health conditions such as Type 2 diabetes and cardiovascular diseases.

To measure your body composition accurately, there are several options available, from bioelectric impedance analysis to callipers and underwater weighing to measure body fat directly.

Overweight, Obese Men

Body Composition vs. Body Mass Index

The main difference between body composition and body mass index (BMI) is that body composition considers the type and location of the fat in your body.

Whereas, BMI compared your total body weight only to your height.

A muscular athlete might have the same BMI figure as an overweight couch potato. The lean muscle mass of the athlete weighs against the body fat of the couch potato. The super-fit athlete clearly has a better body composition than the sedentary couch potato.

Does Skinny Always Equal Healthy?

Being underweight can be just as detrimental as being overweight. Insufficient fat levels can comprise the immune system and prevent correct hormone creation.

How to Measure Body Composition

There are, currently, five body composition analysis methods:

  1. Skinfold tests
  2. Bioelectrical impedance analysis (BSkinfoldIA)
  3. Hydrostatic weighing (underwater)
  4. Air displacement BodPod
  5. DXA/DEXA Scan


Using skinfold callipers the patient can pinch some skin and measure the body fat therein.

The skinfold test can be carried out by the individual themselves but this presents a real element of uncertainty.

It is normal to take skinfold measurements from a number of locations on the body:

  • Stomach
  • Side of the torso
  • Upper thighs
  • Chest
  • Shoulder blade
  • Hip
  • Upper arm or tricep

This is an accurate measure of subcutaneous fat but does not assess visceral fat mass at all.

Moreover, if the individual is not professionally trained the scope for “user error” cannot be overlooked.


Bioelectrical Impedance Analysis (BIA) uses a low-power electrical signal passed through the body to estimate fat-free mass.

Electrical signals pass easily through water, so the high water content of muscle mass presents far less impedance than fat mass.

Bioelectrical Impedance Analysis


This is a form of densitometry that compares your body weight on land to your body weight in water measuring the water displacement to assess your body composition.

This measure is based on the Archimedes principle that the buoyant force on a submerged body is equal to the weight of the water that has been displaced.

In simple terms, muscle sinks and fat floats, so a person with more muscle mass will weigh more underwater.


Similar to the water displacement measurement, air displacement is a way of measuring body fat.

The BodPod uses a mechanical diaphragm to create small volume changes in a confined, calibrate space.

Then, using the understanding that density equals mass over volume, a person’s mass is recorded with their weight. Volume is measured using air displacement. Then, since the fat mass and the fat-free mass have known densities, the BodPod can estimate the fat mass and the fat-free mass of the person.

This way of measuring body composition is very reliable.


Considered to be the most accurate and advanced form of body composition analysis, the DEXA scan uses x-ray technology to assess how much muscle mass and fat mass a body has. From this, an accurate body fat percentage can be calculated.

This will show if you have more body fat than a healthy body composition should have.

Many gymnasium services have a DEXA machine to allow you to analyse your body composition.

Healthy Body Composition

Learn Your Body Composition Macro Goals

Improving your body composition measurements is a challenging undertaking.

The type of food in your diet plays a huge part in the way you can improve your body composition.

But, dietary changes alone are unlikely to be enough to rebalance your body fat distribution.

You need to be physically active even when chronic diseases limit your mobility. Joining a sedentary exercise group class is a great way to incentivise your exercise plans and is a great way of improving your social interaction.

Prior to the pandemic lockdown, I had been part of one of our local sedentary exercise classes.

This was a really positive way to get involved in group exercise classes. And it motivated me to get out of the house and start improving my body composition.

Why Do You Need To Understand Your Weight in Terms of Muscle and Fat Mass?

I am a great believer in a diet for health, as opposed to a diet for weight loss. This way of thinking about weight is what started my need to assess body fat percentage. I already knew that more lean body mass was the target I had to achieve. And the need to lower body fat percentage was the path I chose to follow.

Over the years, my weight has oscillated from a cuddly overweight status to an unhealthy underweight situation. I not only had to understand my body composition, but I also had to understand how my body reacted to the food that I ate.

Additionally, sleep is a significant factor in achieving good health. Surprisingly, getting enough quality sleep can improve your overall body fat percentage.

Methods of Body Composition Analysis

There are a number of methods of body composition analysis. Some are more accurate than others and some are more readily available than others.


Using X-ray technology to measure body composition, Dual energy z-ray absorptiometry can accurately measure the weight of bone, muscle and body fat. This technology is better known as DEXA and can provide an assessment of your bone density, body fat percentage of body fat for each part of your body.

Many health professionals consider this to be the best body composition test. Using and understanding these methods of body composition analysis can provide body composition results that can reduce the health risks of heart disease.

Dual energy x ray absorptiometry can be a very accurate measure of body composition.

Hydrostatic (Underwater) Weighing


Placing the subject in an air-controlled chamber allows plethysmography, a form of hydrostatic weighing, to measure body composition.

If the subject has more lean mass and other lean tissues then there should be no need to lose fat.


How to Improve Body Composition

We can see that a combination of hydrostatic weighing and lifestyle changes can reduce the risk of chronic diseases. Having the correct body composition data will allow you to fine-tune your dietary and exercise regimes to maximise your chances of reaching your health goals.


You may be familiar with the adage that “Sleep is the best healer”. A fact that is borne out by a 2018 study that associated poor sleep quality with:

  • Lower bone mineral density
  • Reduced muscle mass
  • Increased body fat

So, if you wish to improve your body composition, follow these tips for better sleep:

  • Keep a consistent bedtime routine
  • Ensure your bedroom is a cool, dark environment.
  • If you need relaxing sounds, use a fan or soothing noise machine.
  • Do not drink coffee or alcoholic beverages before bed.
  • Exercise regularly

These are all common-sense suggestions that can help you live a fuller, happier life.

How Can BMI Be Inaccurate and Misleading?

For many years, doctors and nutritionists relied on BMI (Body Mass Index) as the measure of a person’s weight when assessing their body fitness This is, generally, a good approach to measuring health but is inaccurate in the case of athletic body types.

It is important when we measure body composition that we take account of the subject’s lifestyle. An athlete or weight lifter places great emphasis on gaining muscle and losing fat.

So, the high muscle mass of this individual will also return a high BMI number.


This may be a little unrelated to the topic. But, I recall a period when I was underweight and went on an exercise plan to build muscle mass. I began a nightly routine of upper arm flexes with small dumbbells to try to build up my biceps.

Because I have an autoimmune disease, maintaining activity levels can be a challenge. My body composition was clearly not optimum, I needed to build lean mass in my upper arms.

I had been losing muscle mass for many years and while I could not estimate body fat or assess fat mass, I know that the health risks of being underweight were also as serious as being overweight in a very different way.

I knew that the important body composition was not so much to lose fat but to gain muscle mass and fat-free tissue. It was clear that body fatness was not an issue.

Losing fat did not need to be my objective. Building muscle mass and fat-free tissue was the order of the day.

After several weeks of exercise, my left bicep was showing visible muscle gain, but my right bicep remained stubbornly flaccid.


Body composition is a measurement of the ratio of fat tissue to lean muscle tissue. Excessive fat, especially visceral fat, can seriously increase the risk of cardiovascular disease and other health conditions.

Maintaining good body composition is a combination of regular exercise, a healthy diet and an awareness of the risks of becoming too flabby.


Verywell Fit
InBody USA
Verywell Health
Trifecta Nutrition
Legion Athletics


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