[Question] how do you actually verify DEXA

Slightly embarrassed to be asking this, but: how do you actually verify DEXA.

Three scans over eighteen months, same machine, same conditions. Only the third one made the first two interpretable.

On comparing yourself to composition figures from trials.

Published composition data comes from supervised populations with structured protocols, standardised scanning, and analysis populations that have been defined in advance. Your two scans at a local clinic, taken in different states of hydration, are not the same measurement.

Use your own baseline. The question worth asking is whether your own trajectory is going the way you want given what you are actually doing, and the honest answer usually requires measuring protein rather than estimating it and being truthful about training frequency. Neither of those is advice — a programme and a target are things to work out with somebody who knows your history.

How to make a DEXA comparison mean anything.

Same machine, same clinic, same protocol. Same hydration and fasting state, as far as you can manage. At least three to four months apart, because the measurement error is large relative to short-term change. Three scans rather than two, because the first pair cannot distinguish a trend from noise.

Do less than that and you have two numbers with an offset of unknown size, which people then react to by rebuilding a training programme. The free alternative — a few tracked lifts and a monthly waist measurement — is directionally informative, costs nothing, and is far harder to over-interpret.

Happy to answer the boring questions. Those are usually the ones worth asking.