Understanding Your Body Composition Report

What is on a Total Body report?

The Desert Dexa Total Body (body composition) report separates your body into fat, lean soft tissue and bone, then reports each one overall and by region. The headline sections are total and regional fat and lean mass, visceral fat, muscle symmetry, Appendicular Lean Mass Index, resting metabolic rate, and total body bone mineral density with regional readings.

It is worth understanding the order in which to read them, because the first number most people look for is the least useful one on the page.

Body fat percentage: the number you came for, and its limits

Your body fat percentage is a real measurement here rather than an estimate — DEXA distinguishes tissue by how it absorbs two x-ray energies, so the figure does not drift with how much water you drank, the way a bioimpedance reading does.

What it will not do is tell you much on its own. A single percentage compresses your whole body into one number and hides where the fat and muscle actually sit. It is the right number to track across scans and the wrong number to fixate on within one.

Regional fat and lean mass: where the answers usually are

The regional breakdown reports each arm, each leg and the trunk separately. This is the section that tends to change behaviour, because it answers questions the scale cannot: whether the training you are doing is adding lean mass where you are training, whether a leg is lagging after an injury, whether weight you have lost came off proportionally.

If you are scanning to track a programme rather than out of curiosity, this is the section to compare between scans.

Visceral fat: the number most people have never seen

Visceral fat is the fat packed around your organs rather than under your skin. It is reported as its own value on every Desert Dexa Total Body report, and there is no way to measure it at home — a scale cannot find it, a tape measure only approximates it, and you can carry a high level while looking lean.

It matters because visceral adiposity is one of the components clinicians look at when assessing metabolic risk, and it moves somewhat independently of your total weight. Two people at the same weight and the same body fat percentage can have meaningfully different visceral scores.

Muscle symmetry: left versus right

The report compares lean mass on your two sides. Some asymmetry is normal — most people are not perfectly balanced, and dominant-side differences in the arms are common. What is worth attention is a large gap, or a gap that is widening between scans, particularly after an injury or a joint replacement. It is one of the more actionable numbers if you are working with a coach or in rehab.

ALMI: the muscle number clinicians use

Appendicular Lean Mass Index is the lean mass in your arms and legs, indexed to your height. It appears on the report because it is the measure used when assessing whether someone has low muscle mass for their frame — a more meaningful benchmark than bodyweight, which counts fat, bone and organs alike.

If you are scanning with longevity or strength in mind rather than aesthetics, ALMI is arguably the single most important line on the page.

Resting metabolic rate

The RMR on your report is derived from your measured lean mass rather than an age-height-weight formula. That distinction matters: a formula assumes an average body composition for someone your size, and the entire reason you had a DEXA scan is that you wanted to stop assuming. If your calorie target came from an online calculator, expect this figure to differ from it.

Bone density on a body composition scan

The Total Body scan also reports total body bone mineral density with a T-score and Z-score, plus regional readings for arms, ribs, legs, spine, trunk and pelvis. This is genuinely useful context, but it is not the same test as a clinical osteoporosis screening, which targets the hip and spine specifically and is read by a radiologist. If bone health is your actual question, see understanding your bone density results and the Osteoporosis Screening scan.

How to read your second report

A single scan is a position. A series is a direction, and the direction is what you can act on. When you compare two Desert Dexa reports, look at regional lean mass and visceral fat before you look at the headline percentage — they move earlier and they tell you more about whether what you are doing is working.

Comparisons only hold if the scans are alike: same fixed scanner, same positioning protocol, similar hydration. That is a large part of why our scanners are fixed-site clinical systems in permanent rooms rather than mobile units re-levelled between sites.

When you get the report

Your Total Body results are reviewed with you at the end of your visit, so you leave already knowing your numbers. The report also ships with a guide to interpreting your own results for when you want to go back through it at home.

This article is for general information and is not medical advice. DEXA results should be interpreted alongside your own clinical history. Talk to your physician about decisions relating to your health.

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