Blog Post

DEXA vs InBody vs Skinfolds

DEXA vs InBody vs Skinfolds

Dual-Energy X-Ray Absorptiometry (DEXA), InBody, and skinfold measurements are all methods used to assess body composition, which refers to the proportion of fat, muscle, bone, and other tissues in the body.

Each approach brings its own advantages and complexities, catering to a diverse range of needs and objectives.

Whether you’re an athlete aiming for peak performance, a healthcare professional tracking patient health, or an individual embarking on a fitness journey, the choice of the right method can significantly impact the accuracy and usefulness of the information you gather.

DEXA

DEXA scan machine with clinician.

The DEXA is often referred to as the gold standard method for assessing body composition.

It uses a low-dose X-ray to differentiate between bone, lean tissue (muscles and organs), and fat. This is a quick process, usually taking 3-10 minutes.

DEXA machines provide the capability to perform regional measurements. This means that instead of just generating a single overall body composition measurement, they can segment the body into different regions, such as arms, legs, trunk and more.

This allows for a detailed analysis of how body composition varies across different parts of the body and can provide insight into how these distributions may affect overall health.

It is also shown to be highly accurate in predicting skeletal muscle mass and more reliable than methods such as InBody and skinfolds for predicting fat mass.

Unlike the other methods, the DEXA can also assess bone mineral density. This information is particularly valuable for assessing bone health and diagnosing conditions like osteoporosis.

DEXA scan results.

The ability to distinguish between different tissue types and provide regional measurements is one of the reasons why DEXA is often considered a reliable method, especially in clinical and research settings.

This is particularly important in fields like sports science, nutrition, and medicine, where a detailed understanding of body composition is crucial.

However, DEXA machines can be relatively expensive and require a skilled technician to operate.

InBody

InBody Scanner.

InBody is a brand that produces body composition analyzers based on the technique of bioelectrical impedance analysis (BIA).

BIA measures the impedance (resistance to the flow of an electric current) of different body tissues, which is used to estimate body composition.

For example, muscle and other lean tissues with high water content conduct electricity more easily, while fat tissue, which contains less water, offers more resistance.

It plots this data into mathematical formulas and algorithms, along with factors like age, gender, height, and weight to estimate body composition.

They are relatively easy to use and provide quick results. However, the accuracy of BIA-based measurements like InBody can be influenced by factors such as hydration status, temperature, meal consumption, and electrode placement.

While it might not provide the same level of accuracy as a DEXA for detailed measurements, it offers a practical and relatively accessible method for quick body composition assessment.

Skinfolds

Skinfold testing with calipers.

This technique involves using calipers to measure the thickness of skinfold folds at specific anatomical sites on the body. 

These measurements are then used in equations to estimate the amount of subcutaneous fat, which is the fat located just beneath the skin.

Unlike the BIA, they are relatively unaffected by factors such as hydration status and food intake.

It’s important to note that the accuracy of skinfold measurements do highly depend on the skill of the technician, the consistency of measurement sites, and the type of calipers used.

Ideally, look for a technician that ISAK Accredited. These individuals have undergone an internationally recognized course and are reassessed every 3 to 4 years to ensure their skills are still sufficient.

Even with this in mind, it is advisable to use the same skilled professional for your measurements on each occasion. This is because variations among service providers can lead to rather noticeable discrepancies, even if they are highly trained.

Skinfold assessments also haven’t been validated for individuals with body fat levels above the ‘normal’ range, and their precision is higher when applied to individuals who have relatively lower body fat percentages.

Overall, skinfold measurements are less sophisticated than a DEXA or InBody but can provide a quick and cost-effective estimation of body fat percentage.

Summary

When choosing a method to assess body composition, it’s important to consider your goals, budget, and the level of accuracy required.

Consulting with a healthcare professional or fitness expert can help you decide which method is best suited for your needs

Ultimately, if finances are not a constraint and you are wanting the highest degree of accuracy and additional information such as bone mineral density and site-specific data, the DEXA scan is probably the best option.

By Josh Wernham

Josh is a Dietitian based in Brisbane who's passion for nutrition stemmed from an interest in optimising sports performance and body composition. He has a lot of experience in bodybuilding style training and also has a background in team sports, strength and endurance events. As he has grown in the field, this enthusiasm has extended beyond just sports and continuously immerses himself in the latest research to support those with general health conditions. He strives to help a range of individuals, from athletes to anyone seeking to improve the quality of their life.