When we want to measure our health and performance, body composition, or body fat, is an important variable to consider!

Body composition is described as the physical components that collectively make up our mass. When we measure our body composition, we are looking to see what proportion of our body is made up of bone, muscle, tissue, and water.

To get an accurate measure of body fat, we often need to analyze our body composition as a whole.

There is a wide range of techniques that are used to measure body composition, each with its pros and cons. No technique exists which can measure our body composition and fat mass 100% accurately, at least while we’re alive.

The only way to accurately measure body composition is by dissection (cadaver analysis), which means that you will unfortunately not be alive to find out the results!

Though, there are some in vivo techniques that are commonly used to provide an estimation of our body composition, which will be discussed in this article!

The Usual Methods of Measuring Fat Loss

When we embark on a fat loss journey, we are told to track changes in our body weight to assess if our diet and lifestyle adjustments are giving us the results we are seeking.

We’re usually told to weigh ourselves using scales once a week, and take body measurements such as waist and hip circumference.

While these are somewhat effective techniques when used consistently and correctly, and being aware of the common inaccuracies, they do not provide an accurate measure of our body fat, which is the exact component we want to be measuring when aiming to lose body fat.

Weighing scales simply measure our weight - this includes fat, bone, muscle, tissue, and water. Our weight can fluctuate from hour to hour, depending on many factors such as:

  • The physical weight of food we consume
  • Water retention
  • Menstrual cycle
  • Medication
  • Carbohydrate intake
  • Salt intake
  • Bowel movements

Not to mention that an effective resistance training program may also cause an increase on the scales as you gain more muscle mass. So, while you may be looking, feeling, and performing better, the scales may not represent this progress. This is why it’s important not to get too hung up on the result!

If you are planning on weighing yourself, it’s best to ensure that each weigh-in is under the same conditions every week. For example, first thing in the morning, after a bowel movement, and before you consume any food or fluids.

To support this, it’s also a good idea to take body measurements at the same time. Tracking changes in the circumference of your waist, thighs, and arms, for example, would be a good way to track changes that aren’t influenced too much by the above factors.

Though, this still doesn’t provide us with an estimation of our body fat. So, how can we do this?

The 5 Best Ways to Measure Body Composition

Knowing what percentage of your weight is fat mass and fat-free mass will give you a much better outlook on your health, as well as a more accurate representation of your fat loss progress.

Having more in-depth information about your body composition would also allow you to make better adjustments to your diet, lifestyle, and training routines. So, you could say that knowing your body composition is key for optimal performance and appearance!

Thankfully, some techniques can provide an estimation of your body composition. While none of these techniques are 100% accurate, it is far more effective than simply taking a bodyweight measurement.

1) DEXA/DXA Scan

A DEXA scan is considered to be one of the most accurate and comprehensive body composition tests. The DEXA scan uses x-rays to look at body composition in defined regions, looking more specifically at areas where fat is being stored.

A DEXA scan can also measure visceral/abdominal fat, which is often associated with an increased risk of developing cardiovascular disease and type 2 diabetes.

DEXA scans are fairly quick procedures, taking around 10 - 15 minutes to complete. It also has a high level of precision and a low dose of radiation, making it the “gold standard” body composition measuring technique.

Pros: It is the most precise method, making it very repeatable. It gives you a very good indication of body fat percentage.

Cons: It is hard to access and can be quite expensive. It may not be necessary for the general population.

2) BodPod

Based on Air Displacement Plethysmography (ADP), the BodPod uses whole body densitometric principles to establish fat and fat-free mass.

This technique measures air displacement, which resembles a chamber that people are required to enter. Upon entry, the air pressure is measured to determine the amount of air displaced, thus allowing for an estimation of body volume.

It’s a simple technique, not as invasive as a DEXA scan, and requires minimal time.

Pros: It is a safe and accurate method that’s more accessible than a DEXA scan.

Cons: It’s still not as accessible as other methods, and does require some confidence in wearing minimal clothing to partake in the test.

3) Underwater/Hydrostatic Weighing

Hydrostatic weighing, also known as underwater weighing, is based on the same densitometric principles as the BodPod. This technique compares your normal body weight outside of water to your body weight while submerged in water.

Upon comparing these two results and the density of the water, you can accurately determine body volume and density along with a measurement of fat and fat-free mass.

Pros: It is a very accurate method based on robust principles.

Cons: Once again, it is very difficult to find and requires confidence in the water.

4) Skinfold Measurements

One of the most accessible methods of measuring body composition, skinfold analysis measures the thickness of your skin and the subcutaneous fat at specific locations on your body.

Once the test is complete, the measurements are put through a formula that can determine your body composition.

While you can purchase your own skinfold calipers to perform this test at home, it will not be as accurate as a practitioner performing the test.

Pros: It is accessible, easy, and does not require much time.

Cons: For the most accurate results, it requires a qualified practitioner. Even so, the margin for error can vary depending on the experience of the technician.

5) Bioelectrical Impedance Analysis (BIA)

BIA involves standing on a scale while a low-level electrical current is sent through the body. Tissues that contain fluid, such as blood, have high conductivity, while fat and bone tend to slow the signal down.

This can determine the amount of resistance to the current as it passes through the body, providing an estimation of body fat and body water.

Pros: It is a very quick test and simply requires you to stand on a scale. It is also very accessible and somewhat affordable.

Cons: BIA has been shown to not be as accurate as we once thought. It is sensitive to factors such as skin temperature, mealtimes, and hydration.

The Final Take-Home

There are many techniques for measuring body composition, and thus estimating body fat percentage.

However, many of the more accurate techniques are not easily accessible or very affordable, nor are they often necessary for the general population.

If you are seeking an estimation of your body fat percentage, it’s best to stick to the more affordable, accessible options such as BIA and skinfold assessments, preferably completed by a practitioner.

Otherwise, tracking your fat loss progress by body weight, waist measurements, and assessing your performance and other lifestyle factors would also be just as beneficial, from a progress tracking standpoint!