Understanding Your DXA Scan

A DXA scan provides body composition insights beyond weight, revealing fat, lean mass, and bone distribution. While not perfect, "DXA is established as a precise, accurate method of estimating body composition." Small changes accumulate over time; focus on trends rather than isolated measurements.

Understanding the DXA report

Main Metrics:

Total mass (body weight in pounds/kilograms)
Fat mass (total or regional, in pounds/kilograms)
Bone mineral mass (BMC, in pounds/kilograms)
Lean soft tissue (organs and tissues excluding fat/bone)
Body fat % (fat mass divided by total mass × 100)
Visceral fat (deep abdominal fat around organs)

Additional Terms:

T-Score (compares density to healthy young adult average)
Z-Score (compares density to same age/sex/ethnicity group)
Fat-free mass index (FFMI)
Appendicular Lean Mass Index (ALMI)
Android/Gynoid Ratio (belly fat vs. hip/thigh fat)

Note: "(e)" designation indicates estimated values when body portions are "cut off" in imaging.

What to Do With Your DXA Data

Focus on five key metrics:

Total mass
Entire body fat mass
Entire body lean soft tissue
Entire body bone mineral mass
Total body fat percentage

Two primary uses: (1) Compare composition against population standards or risk categories, (2) Track changes across multiple assessments at same facility.

How should I prepare for my DXA scan?

Consistency in Scheduling: Perform exams at same time daily across sessions.

Pre-exam Preparation: Morning fasting ideal; maintain consistency in eating/drinking; avoid exercise day-of; empty bladder beforehand; wear metal-free clothing; remove jewelry.

Equipment Variation: Different manufacturers produce varying results; consistent facility testing improves accuracy.