Comparing InBody and DEXA for Body Composition Accuracy

On 28 April 2023, one week before my NPC regional bodybuilding competition, I compared an InBody scan with a DEXA scan to assess how closely the two methods align.

Test setup

• InBody scan performed in the morning, fasted

• DEXA scan completed approximately 2 hours later

• No food consumed between tests (only 1–2 glasses of water)

Key comparison results

• Body fat percentage: difference of 0.2%

• Fat mass: difference of approximately 300 g

• Fat-free mass: difference of approximately 1.7 kg

The 1.8 kg difference in total body weight suggests a likely calibration variance of the DEXA scale, which would also explain the higher fat-free mass reported by DEXA.

Why this comparison matters
DEXA is considered the reference method for body composition. InBody claims accuracy close to DEXA, and this side-by-side test was a practical way to validate that claim under controlled conditions.

Conclusion
When measured under consistent conditions, InBody and DEXA produced very similar body fat results, supporting the reliability of InBody for tracking body composition trends.