They estimate body composition in different ways.
DEXA estimates body composition from how tissues absorb two X-ray energies. InBody devices use bioelectrical impedance: electrical measurements taken through contact electrodes are used to derive body water and body composition estimates.
InBody is a brand, not another name for DEXA. Its device models and available outputs vary. Similar-looking body fat or lean-mass numbers do not make the two methods interchangeable.
Compare the methods
| Feature | DEXA | InBody |
|---|---|---|
| Measurement method | Low-dose X-ray attenuation. | Bioelectrical impedance through electrodes. |
| Typical report | Fat mass, lean soft tissue and bone mineral, with regional analysis. | Body water and derived fat and fat-free mass estimates; outputs vary by model. |
| Bone density | A dedicated diagnostic protocol can measure bone mineral density. | Not a diagnostic bone density examination. |
| Preparation | Follow the clinic’s protocol and keep repeat-scan conditions consistent. | Follow the instructions for the particular device and appointment. |
| Following change | Use a comparable scanner, protocol and preparation; ask about measurement variation. | Use the same method and device conditions; do not splice results into a DEXA trend. |
Which is more accurate?
An accuracy percentage without a defined measurement, device, comparison method and study population is not enough to choose a test. Precision, which describes repeatability, is also different from accuracy.
Ask which method answers your question and how the provider handles measurement variation. A small difference between two methods is not proof that your body has changed. For DEXA follow-up, ISCD emphasises consistent preparation and appropriate cross-calibration when comparing systems.
ISCD: official adult positions, including body composition ↗
Choose for the question you need answered.
For a medical bone health concern, speak with your GP about the appropriate diagnostic assessment. For body composition, ask the provider what the report includes and whether someone will explain its limitations.
If you already have an InBody result, keep it clearly labelled with the method and date. A later DEXA can be a new starting point rather than an assumed continuation of the same measurement series.
About the sources
The InBody source describes its own technology. We use it to explain the measurement method, not as independent evidence that one brand or test is superior. ISCD supplies the professional guidance on DXA preparation and comparison.