Can a DEXA scan measure body fat?

The scanner distinguishes bone mineral from soft tissue and produces an estimate of fat mass and lean soft tissue. It may show how these compartments are distributed between regions such as the arms, legs and trunk. Lean tissue is not identical to muscle, because it includes other non-fat soft tissues and can be influenced by hydration.

A body-composition report is different from a bone-density report. The estimate can help a clinician follow a particular question over time, but it cannot by itself explain why weight, strength or body shape has changed.

Use the same facility and a similar routine when comparing scans. Tell the team about recent food or fluid intake, exercise, swelling, pregnancy, implants and medicines if they ask, because these factors can affect interpretation. Wear comfortable clothing and follow the centre’s preparation advice.

Ask whether the service is measuring composition for a specific medical reason or for general tracking. DEXA Scanner describes the equipment, and Bone Density Scan explains its better-known bone-health use.

Do not use a body-fat result to explain sudden swelling, rapid unplanned weight change, severe weakness or breathlessness. Arrange medical review for those symptoms, especially if they are worsening. After a fall, seek prompt assessment for severe pain, inability to stand or a new deformity rather than waiting for a composition scan.

Ask what the scan is intended to measure, how hydration or recent exercise may affect it, which regions will be reported, and what change would be meaningful for your care. Ask how the findings fit with your diet, activity, medicines, strength and other health conditions.