Interpreting DEXA Scan Results: A Comprehensive Guide

Receiving your own Dual-Energy X-ray Absorptiometry (DEXA) scan can be great for having an accurate assessment of your body composition and bone mineral density.

They offer invaluable insights for athletes, the general population, and individuals at risk of osteoporosis.

There is quite a lot of data and various sections in the report, so understanding these results can be important to taking steps towards your goals.

Reference Comparison

There are numbers on the report comparing your data to certain demographics.

• YN: ‘Young Normal’ (20-29 year-olds).
• AM: ‘Age Matched’ (Age specific).

This is based off the ‘National Health & Nutrition Survey’ (NHANES) Data. It includes >20,000 participants, aged 8-85, with the data solely collected on Hologic equipment (what we use in clinic).

Bone Mineral Density (BMD)

The first page highlights all of the relevant information regarding your BMD.

Summary Table

This separates your data into each body compartment and provides the totals. There are also separate headings to be aware of.

• BMC: Bone mineral content i.e. the total weight of your bones.
• BMD: Bone mineral density. This is the BMC divided by the area (grams/cm²).

BMD Graph

Your BMD results are compared with two norms – a young healthy population (T-score) and age-matched (Z-score).

• T-score: Indicates how your bone density compares to the optimal or peak bone density of a healthy, young adult of the same sex. T-scores are categorized as follows:
  • Above -1: Normal bone density.
  • Between -1 and -2.5: Indicates osteopenia, a condition where bone density is below normal and may lead to osteoporosis.
  • Below -2.5: Indicates osteoporosis, a condition characterised by weak and brittle bones.

Important to note: A whole-body bone density provides you with the total bone mass and bone mineral density (BMD) but cannot provide a diagnosis of osteoporosis.

Total Body Composition Results

This is where you can see the amount of fat, lean and bone mass in each compartment.

• Android: The amount of fat around your midsection.
• Gynoid: The amount of fat around your hips.
• Fat Mass: Total body mass in grams e.g. 19.6kg.
• Lean + BMC: Total fat free mass (lean mass + bone mineral content) e.g. 65.9kg
• % Fat: This represents your total body fat percentage e.g. 22.9%.

The body fat % is shown for different areas of the body. For example, the android percentage represents how much you have around the midsection i.e. what is typically looked at for showing the abdominal muscles.

This is why two individuals with 15% total body fat may have differences in the amount of abs showing.

Colour Map

The colour map is an image of showing the location of bone (blue), lean mass (red) and fat mass (yellow).

Fat Mass

Body Fat % Graph

This graph plots your body fat percentage (white marker) in comparison to your age group (using Z – scores).

• Z Score = 0: The value is exactly at the mean.
• Z Score > 0: Indicates the value is above the mean.
• Z Score < 0: Indicates the value is below the mean.

The numbers represent standard deviations from the mean:

• About 68% of the data falls within one standard deviation of the mean (between Z scores of -1 and 1).
• About 95% of the data falls within two standard deviations of the mean (between Z scores of -2 and 2).

Adipose Indices

This breaks down the body fat into separate components and compares this to different demographics.

• YN (20-29 year-olds): In this example, 68% of people in that age group have a lower body fat percentage than you.
• AM (Age specific): 80% of people your age have a lower body fat percentage than you.

Body fat % can be influenced by total muscle mass (i.e. the higher your muscle mass, the lower the percentage will be, despite having the same body amount of body fat).

To account for this, the ‘Fat Mass/Height²’ indices represent how much body fat you have across your height.

Android/Gynoid Ratio: A higher A/G ratio suggests a greater proportion of fat is stored in the android region, which is associated with an increased risk of cardiovascular diseases, cancer, type 2 diabetes, and metabolic syndrome.

VAT = Visceral Adipose Tissue (the fat around the internal organs).

‘Est. VAT Area (cm²)’ represents the amount visceral fat present per squared centimeter. Interpreting results can be difficult as there is a lack of appropriate reference ranges. However, with the current research, the rages below may be used as a general guide towards identifying varying levels of health risks.

Lean Mass

Lean/Height² = Amount of muscle mass in the body respect to your height(e.g. muscle mass in kg each squared metre. In this example, 60% of 20-29 year olds & those your age have more muscle mass than you.

Appendicular Lean/Height² = The amount of muscle mass you have not including your trunk. i.e. muscle mass in your arms and legs.

Rate of Change

When you have a follow-up scan, you will receive an additional page comparing your current to your previous results.

It will highlight the overall change in body fat percentage, total fat mass, total lean mass, and total mass in grams.

How to Use This Information

Understanding your DEXA scan results can provide valuable insight into your own unique composition and how it aligns with your health and fitness goals.

This can be used to assist your health, fitness and performance goals with assistance from a qualified or accredited professional such as a Dietitian, Sports Nutritionist, or Personal Trainer.

If you’re looking to use these results to inform your training and nutrition, you may have been referred to us by your healthcare professionals who can provide you with this comprehensive guidance and recommendations.

Or you can book a consult with the team of dietitians at our referral partner Ideal Nutrition. Their team can provide tailored nutrition plans to help you reach your objectives.