What Is DEXA Scanning?
DEXA (English: Dual-Energy X-ray Absorptiometry) — is a medical test that uses X-rays of two different energies to determine body tissue composition. It is the gold standard in body composition measurement.
DEXA can accurately measure: total and regional body fat mass, lean body mass (muscles, organs), bone mineral density (BMD) — an important osteoporosis indicator, visceral fat (some models).
Gold Standard
Accuracy ±1-2% — the highest among all body composition methods. Used as a reference method for calibrating other devices.
Bone Health
DEXA also measures bone mineral density (BMD), which is the main diagnostic criterion for osteoporosis. T-Score <-2.5 indicates osteoporosis.
Regional Analysis
DEXA provides separate data for each body part: arms, legs, trunk, head. This helps identify muscle asymmetries.
Progress Tracking
It is recommended to get tested every 3-6 months to track body composition changes — muscle growth or fat loss.
📊 DEXA vs Other Methods
| Criterion | DEXA | Bod Pod | BIA | Caliperometry |
|---|---|---|---|---|
| Accuracy | ±1-2% | ±1-3% | ±3-5% | ±3-5% |
| Bone density | Yes | No | No | No |
| Regional data | Yes | No | Some | No |
| Radiation | Very low (1-4 µSv) | None | None | None |
| Duration | 10-20 min | 5-10 min | 1-5 min | 10-15 min |
| Price | ~80-150 € | ~50-100 € | ~20-50 € | ~10-20 € |
How Scanning Is Performed
DEXA (dual-energy X-ray absorptiometry) scanning measures bone mineral density and body composition — the distribution of fat, lean mass and bone. The procedure is quick and non-invasive: you lie still while the device scans your body.
DEXA is considered one of the most accurate body composition methods; moreover, it shows fat distribution in individual body parts, not just the total amount. This makes it possible to see where fat accumulates and how muscle mass changes in individual areas.
How to Interpret the Result
The result provides not only total body fat percentage but also its distribution and bone density. Evaluate it using age- and sex-specific tables or a specialist's opinion.
The greatest value of DEXA is the ability to accurately track changes: a repeat scan after a few months shows whether fat decreased and muscle increased. Bone density data additionally helps assess bone health.
Common Mistakes
- Different devices between measurements — results may not match.
- Eating or drinking before the test — can affect the result.
- Scanning too often — changes should be assessed every few months, not more often.
- Overemphasizing a single number — the trend is more important.
When the Result Is Unreliable
The result is misleading if the test was performed on different devices or the preparation rules were not followed. To compare with other methods, see the comparison of body composition methods or body fat calculator.
🙋 Frequently Asked Questions
Is DEXA Safe? The test uses a very low radiation dose and is considered safe, but it is generally not recommended for pregnant women.
How Does It Differ from Other Methods? DEXA shows not only total fat amount but also its distribution and bone density, which other methods do not show.
How Often Should You Get Scanned? Once every few months is enough to see real changes in body composition.
Is DEXA Suitable for Athletes? Yes, it allows accurate tracking of muscle and fat changes in individual body parts, so it is useful for assessing the effect of training.
Do You Need to Prepare for the Test? Usually it is enough to avoid eating before the test and wear comfortable clothing without metal parts.
If you are taking the test to track the effect of training, repeat it after a few months on the same device and under similar conditions — only then will the comparison be reliable and show the true change.
Discuss the result with a specialist who will help correctly interpret not only total body fat percentage but also distribution and bone density — these data are valuable only when assessed together.
Use the test not only to assess body composition but also bone health — bone density indicators help detect changes in time, especially at an older age.