A useful report conversation starts with three details: the exact measurement, the units and the reason the scan was performed. Keep those details beside the number as you read. The reference material below explains how published comparisons work; it cannot decide whether your individual result needs treatment.
If your report uses a different scanner, region or reference population, ask the clinic which comparison applies. Avoid substituting a convenient online table just because the units look similar. Discuss bone density or visceral fat findings with your GP.
Read the measurement
DEXA estimates visceral adipose tissue, often shortened to VAT. Identify the scanner and units first: kilograms, grams, volume and area are different measurements.
| Age | Men: mass / volume | Women: mass / volume |
|---|---|---|
| 18-19 | 0.18 kg / 186 cm³ | 0.04 kg / 45 cm³ |
| 20-24 | 0.25 kg / 261 cm³ | 0.06 kg / 60 cm³ |
| 25-49 | 0.71 kg / 746 cm³ | 0.55 kg / 579 cm³ |
| 50+ | 1.62 kg / 1,708 cm³ | 1.21 kg / 1,285 cm³ |
Read the label before the colour
Visceral fat is fat inside the abdominal cavity. It is different from all abdominal fat and from the android region used in body composition analysis. A report can contain both an android measurement and a VAT estimate without those labels referring to the same compartment.
GE CoreScan reports can give VAT mass and volume. Hologic software can report VAT area and mass. Software version and analysed region matter as well as the manufacturer name. Do not transfer a number from one unit to a threshold in another unit.
What a population median tells you
The GE table summarises medians reported in a US iDXA cohort of 649 adults. A median is the middle of the reference distribution, not a recommended upper limit. The broad 25 to 49 age group also contains people at many different stages of life.
Our invented example has VAT of 0.62 kg and 655 cm³. Those are slightly above the reported female median of 0.55 kg and approximately 579 cm³ for ages 25 to 49 in that cohort. That observation does not label the example healthy or unhealthy, and it cannot determine a treatment need.
A report’s coloured categories may come from a manufacturer-specific interpretation system. We have not independently verified the requested Hologic manual thresholds for the exact software version, so they are not reproduced here as advice. Ask your clinic for its current manual and reference.
Accuracy is not interchangeability
Validation research compares DEXA estimates with another imaging method such as CT. Agreement at a group level does not mean every individual estimate is exact, or that two manufacturers’ values can be swapped. Later cross-system research specifically examines these differences.
When tracking, use the same scanner and analysis protocol where possible. Ask whether a software change or region adjustment affects comparability. Keep the complete report rather than recording only a colour label or one rounded number.
What to do with a concerning result
Discuss your visceral fat result with your GP. The useful question is how it fits your history and other relevant findings, not simply whether it is above a cohort median. Your GP may consider measurements and tests beyond the scan. The DEXA report is one piece of that conversation.
A dietitian or other treating practitioner can help translate agreed goals into practical steps. A generic target number or guaranteed timeline would miss differences in health, medication, training and circumstances. If repeating the test, agree what decision the new result would inform and ask about VAT-specific repeatability.
Do not calculate a personal risk percentage from the table. The table describes the published population; it does not measure your chance of a future event. A change smaller than the clinic’s reliable measurement threshold may also be difficult to distinguish from ordinary variation.
Questions for your practitioner
- Is my VAT shown as area, mass or volume?
- Which manufacturer reference explains the colour band?
- How does this fit my health history, and would a repeat scan change care?
Sources checked 23 September 2026: Source 1 · Source 2 · Source 3 · Source 4. New reference material prepared by DEXA Scans Australia; not included in Kristof’s earlier review.
Common questions about results
What is a good body fat percentage on a DEXA scan?
There is no single percentage that suits everyone. Published tables describe a reference population, not a target. Check the scanner, age group and sex group, then discuss the result alongside your health, strength, nutrition and reason for testing.
Why is my DEXA percentage different from my smart scale?
DEXA and bioimpedance scales estimate body compartments using different measurements and assumptions. Hydration and preparation can also affect comparisons. Neither an automatic correction factor nor combining both methods into one trend is reliable.
What does ALMI mean?
Appendicular lean mass index is arm and leg lean tissue divided by height in metres squared. It is one measure of muscle quantity. It does not measure strength and cannot diagnose sarcopenia by itself.
Is a Z-score of -1 bad?
ISCD describes adult Z-scores above -2.0 as within the expected range for age. That wording is a reference comparison, not a complete assessment of bone health. Ask your GP about the scan site, report conclusion and your medical history.
How often should I have another scan?
Agree on an interval that answers a useful clinical or training question. The reason for testing, expected change, scanner precision and whether the scan is for bone density or body composition all matter. There is no universal schedule for everyone.
Does lean mass mean muscle mass?
No. Lean soft tissue includes water and organs as well as muscle. Bone mineral content is reported separately. A change in lean tissue can reflect more than a change in muscle.
Can I compare results from GE and Hologic?
Do not treat values from different scanner families as interchangeable. Software, calibration, region definitions and reference databases differ. Ask the clinic whether a meaningful comparison is possible before interpreting a change.
Does a whole-body scan diagnose osteoporosis?
A body composition scan is not a substitute for a diagnostic bone density assessment at appropriate sites. Your GP or specialist interprets bone health findings alongside age, menopause status, fracture history and other relevant information.
How do I know if a change is larger than measurement variation?
Ask the clinic for its least significant change for the measurement. At 95% confidence, the usual calculation is 2.77 times measured precision error. Our calculator is an illustration and cannot replace the clinic’s precision assessment or confirm why a number changed.
Keep the result useful
Save the original report, including its scanner details and reference notes. At a later appointment, bring the earlier copy rather than relying on a rounded value entered in an app. Ask whether preparation, positioning and software were comparable, and whether the change is large enough to influence the decision you are making.
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