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
Regional analysis describes where measurements were taken. Ratios compare selected regions, but the definitions and region boundaries need to match before you compare reports.
Android/gynoid fat ratio references
The source uses a reversed fitness-style ranking: 90th means the lower end of the distribution, 10th the higher end. These labels do not measure fitness or health.
| Age | n | Mean ± SD | 90th | 80th | 70th | 60th | 50th | 40th | 30th | 20th | 10th |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20-29 | 562 | 0.33± 0.11 | 0.20 | 0.24 | 0.26 | 0.28 | 0.31 | 0.34 | 0.36 | 0.40 | 0.47 |
| 30-39 | 196 | 0.39±0.17 | 0.20 | 0.24 | 0.29 | 0.33 | 0.37 | 0.40 | 0.43 | 0.49 | 0.62 |
| 40-49 | 258 | 0.44±0.17 | 0.24 | 0.29 | 0.34 | 0.38 | 0.41 | 0.46 | 0.50 | 0.56 | 0.63 |
| 50-59 | 437 | 0.48±0.18 | 0.28 | 0.35 | 0.39 | 0.43 | 0.46 | 0.51 | 0.55 | 0.60 | 0.69 |
| 60-69 | 440 | 0.50±0.15 | 0.32 | 0.38 | 0.42 | 0.45 | 0.48 | 0.52 | 0.57 | 0.62 | 0.72 |
| 70-79 | 183 | 0.46±0.13 | 0.31 | 0.36 | 0.40 | 0.44 | 0.47 | 0.50 | 0.54 | 0.59 | 0.66 |
Choose an age to highlight a row. No values are sent to the server.
Population reference, not a target. 3,327 US adults, 95% Caucasian; GE Lunar Prodigy or iDXA. These are not Australian norms or athlete targets. Source and table ↗ · Checked 23 September 2026.
Trunk/limb fat ratio references
The source uses a reversed fitness-style ranking: 90th means the lower end of the distribution, 10th the higher end. These labels do not measure fitness or health.
| Age | n | Mean ± SD | 90th | 80th | 70th | 60th | 50th | 40th | 30th | 20th | 10th |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20-29 | 562 | 0.96±0.25 | 0.71 | 0.79 | 0.85 | 0.88 | 0.92 | 0.97 | 1.03 | 1.10 | 1.21 |
| 30-39 | 196 | 1.06±0.34 | 0.72 | 0.80 | 0.86 | 0.92 | 1.01 | 1.06 | 1.15 | 1.23 | 1.48 |
| 40-49 | 258 | 1.12±0.39 | 0.76 | 0.86 | 0.93 | 0.97 | 1.03 | 1.12 | 1.20 | 1.31 | 1.48 |
| 50-59 | 437 | 1.18±0.39 | 0.79 | 0.89 | 0.99 | 1.05 | 1.13 | 1.21 | 1.30 | 1.42 | 1.62 |
| 60-69 | 440 | 1.15±0.29 | 0.82 | 0.92 | 0.98 | 1.04 | 1.12 | 1.19 | 1.28 | 1.36 | 1.55 |
| 70-79 | 183 | 1.12±0.26 | 0.80 | 0.89 | 0.99 | 1.06 | 1.12 | 1.16 | 1.22 | 1.30 | 1.44 |
Choose an age to highlight a row. No values are sent to the server.
Population reference, not a target. 3,327 US adults, 95% Caucasian; GE Lunar Prodigy or iDXA. These are not Australian norms or athlete targets. Source and table ↗ · Checked 23 September 2026.
Android and gynoid are regions
Android refers to an abdominal region; gynoid refers to a region around the hips and upper thighs. The software draws these regions using its analysis rules. An android result is not a direct synonym for visceral fat, because abdominal tissue includes other compartments.
An android-to-gynoid ratio may compare regional fat percentages. Read the report definition before calculating it yourself. Dividing android fat kilograms by gynoid fat kilograms is a different operation if the report expects a ratio of percentages.
Use the matching reference table
Imboden and colleagues published GE-specific percentiles for android/gynoid and trunk/limb ratios. Their sample was predominantly Caucasian US adults scanned on Lunar Prodigy or iDXA. The tables do not establish a universal ratio that everyone should aim below.
The study’s reversed ranking puts lower values towards the higher numbered percentiles. This presentation describes the distribution in that source. It does not turn a regional ratio into a fitness grade, nor does a low ratio necessarily mean that all relevant health measures are favourable.
Trunk/limb and trunk/leg ratios are not interchangeable. A denominator containing all limbs includes the arms as well as the legs. The name, units and formula should be recorded along with the value. The exact region definitions are part of the measurement.
A small asymmetry is not an injury diagnosis
Left and right regions let a practitioner compare corresponding limbs. Compare the same compartment on both sides: left arm lean tissue with right arm lean tissue, for example. Comparing fat on one side with lean tissue on the other creates a meaningless difference.
Our example shows a 0.3 kg lean difference. We do not call this “normal” or “under typical asymmetry”, because a universal threshold is not established by the cited tables. Positioning, analysis boundaries, limb size and the reason for the test all affect what a difference means.
What matters at a repeat appointment
Ask whether the regions were reviewed and drawn consistently. A small change in a boundary can shift tissue from one region into another without changing whole-body composition. This can make a regional result look different while the total remains similar.
If the question concerns injury or function, a clinician also needs symptoms, examination and relevant history. DEXA alone cannot identify why a side differs or prescribe a rehabilitation programme. A repeated asymmetry can be worth discussing without being treated as proof of a problem.
Keep regional comparisons within the same scanner system and protocol when possible. There is no general number of weeks after which a ratio should improve. Agree on the question and the likely size of a useful change before booking another scan.
Questions for your practitioner
- Does this ratio use fat mass or fat percentage?
- Were the region boundaries checked consistently?
- Does the side-to-side difference fit any symptoms or functional findings?
Sources checked 23 September 2026: Source 1 · Source 2. 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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