DEXA Scans: The Most Precise Way to See What You Are Made Of

Dual-energy X-ray absorptiometry, or DEXA (sometimes written DXA), uses two low-dose X-ray beams to distinguish between fat mass, lean mass, and bone mineral content throughout the body. Because the two beams are absorbed differently by these tissue types, the scan can calculate composition directly rather than estimating it from a formula.

A full DEXA report breaks composition down by region, arms, legs, trunk, and total body, which lets you see whether muscle or fat is distributed evenly or concentrated in specific areas. It also reports visceral adipose tissue, the fat stored around internal organs, and bone mineral density, neither of which a smart scale can assess.

BIA scales, discussed in our smart scales guide, estimate composition indirectly from electrical resistance and population formulas. DEXA measures tissue composition directly through X-ray attenuation, which is why it is considered a reference standard in body composition research, alongside hydrostatic (underwater) weighing.

Hydrostatic weighing estimates composition based on body density using water displacement and is highly accurate but requires full submersion, which makes it less accessible than DEXA for routine use. DEXA offers comparable accuracy with a faster, more comfortable scan and the added benefit of regional and bone density data.

Where fat is stored matters for health, not just how much fat exists in total. Visceral fat, the fat surrounding organs in the abdominal cavity, is associated with different health considerations than subcutaneous fat stored just under the skin, and DEXA is one of the more accessible ways to get an actual visceral fat measurement rather than an estimate from waist circumference alone.

Bone mineral density, also reported in a DEXA scan, matters throughout life but becomes especially relevant with age, since bone density naturally declines over time. Resistance training and adequate protein intake support bone health alongside muscle, which is part of why Styles Coach treats these measurements as connected rather than separate concerns.

Body composition changes meaningfully over a period of months, not days, so I recommend rescanning every eight to twelve weeks during an active training or fat-loss phase, and less frequently, perhaps every six months to a year, during a maintenance phase.

To get a consistent reading between scans, I recommend scanning under similar hydration conditions each time, avoiding intense exercise in the 12 to 24 hours prior, and avoiding scanning during unusually high water retention, such as immediately after a very high-sodium meal.

A DEXA report will typically show total fat mass, total lean mass, body fat percentage, regional breakdowns for arms, legs, and trunk, visceral fat area, and bone mineral density or a related bone health score. I recommend comparing each of these figures scan to scan rather than fixating on any single number in isolation, since the trend across scans is what reveals whether training and nutrition are working as intended.

For anyone in or near Peoria, Illinois, Styles Studios Fitness offers in-person DEXA scanning as part of its facility, giving clients a direct path from scan results to a coached plan built around them.

Inside Styles Coach, your DEXA results can be logged and tracked scan over scan, so fat mass, lean mass, visceral fat, and bone density trends sit alongside your training and nutrition history in one continuous view, rather than as disconnected reports.