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Body composition · scan guide

DXA body composition scan: what the results mean

DXA (often called DEXA) is an X-ray scan that estimates how much of your body is fat, lean tissue and bone. It can show what changed between scans, but it cannot explain why it changed or choose a treatment.

Source: Five medical and government sources, checked 2026-08-22

What matters first

Main estimates
Fat, lean tissue and bone
Useful for
Seeing what changed between scans
For a fair comparison
Keep the scan setup consistent
Cannot decide
Why a change happened or what to do next

Start with the big picture

What the scan shows

A scale shows one total number. A DXA scan separates that number into estimates for fat, lean tissue and bone. That can make a change easier to understand.

Fat

How much of the measured mass the scan estimates is body fat.

Lean tissue

Muscle is part of this number, but so are water, organs and other soft tissue.

Bone

The report may include both the amount of bone mineral and how densely it is packed.

Body composition

How is your weight divided?

This side of the report estimates fat mass, lean mass and body-fat percentage. It is the part people usually mean when they ask about a body composition scan.

Bone density

How dense is the bone measured?

Bone mineral density answers a different health question. Ask the imaging center what your appointment and report include; not every scan package is the same.

Your results, translated

The numbers you may see on the report

A facility may show all of these or only some of them. The names can vary slightly, but the basic ideas stay the same.

Total mass
The body weight counted by the scan. It is divided into fat, lean tissue and bone mineral.
Fat mass
The estimated weight of fat in the area measured or across the whole body.
Lean mass
Everything that is not fat or bone mineral. It includes muscle, organs, water and other soft tissue.
Body-fat percentage
The share of the measured body mass that the scan estimates is fat.
Bone mineral content
The estimated amount of mineral in the bones measured by the scan.
Bone mineral density
A measure of how much bone mineral is packed into a given area. It answers a bone-health question, not a muscle question.

Repeat scans

Make the next scan easier to compare

A real body change and a different scan setup can both move the numbers. Consistency makes the comparison more useful.

  1. 01

    Use the same facility

    When practical, return to the same scanner and reporting method.

  2. 02

    Follow the same preparation

    Use the center’s instructions and keep timing and clothing similar.

  3. 03

    Ask about small changes

    The center can explain its measurement precision before you treat a small difference as progress.

Put the result to work

Where DXA fits into a weight-loss journey

The scan can add context to the number on the scale. Keep it beside your other records—not in place of them. Start with the broader weight-loss guide, then use the tool that matches your next question.

Track weight changeSee your percentage change and progress toward a goal without predicting what happens next.Open tool Estimate lean massUse a body-fat estimate to see the simple math behind fat mass and lean mass.Open tool Plan daily proteinTurn a protein goal into a practical daily plan. The planner does not set a medical target.Open tool

Keep the result in bounds

What the scan cannot tell you

  • Why your body composition changed.
  • Whether one change caused a symptom or health result.
  • Which medicine, diet or exercise plan is right for you.
  • Whether a small difference is larger than the scanner’s normal measurement variation.

Verified access is still being built

Why there is no provider finder on this page yet

There are not enough checked listings with a named service and current availability to make a useful DXA directory yet. We will add search only after the network passes that quality gate.

Keep reading

Beginner, everyday and emerging-topic guides

Approved products, human research and online claims stay visibly separate across the library.

Estimate lean mass and fat mass

Uses current weight and one body-composition number the reader already has.

Compare current weight with where you started

Runs in the browser, requires no account and sends no entered values to HealthspanLedger.

See what remains in a daily protein ledger

The same validated model drives the on-screen result, copied summary, shared URL and print view.

The weight loss table, basis by basis

Compare why people use each compound with what human studies have actually measured for weight loss.

What the source labels on this page mean

How an FDA label differs from a human trial, limited human data or no established human dose.

Medically reviewed by Jennifer Montecillo, MD · non-practicing medical reviewer

Reviewed 2026-08-22

5primary sources, each with the day we read it — open the documents used on this page