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How do I set up a DEXA sequence that is actually comparable over time?

Asked 16 Dec 2025Modified 4 months agoViewed 13k times
20

I would like to know what to measure as much as what to do.

Everything I have found on this is either a forum aside or a product page, neither of which I trust.

I am comfortable with the arithmetic; what I am missing is the procedural detail around it.

What is the correct sequence, and where is the step that people usually skip?

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DH
askedDr_Jonas_Halvorsen41k3816 Dec 2025

5 Answers

Accepted answer first, then by votes
5

Accepted answer

To be exact about it, start with the arithmetic, because the answer to the practical question is usually a number and the number is usually achievable.

Absolute strength holds up better than scale weight during a deficit for a straightforward reason: strength is substantially neural and skill-based, and the contractile tissue you retain is being trained harder relative to its size. Grip strength and repetition maxima are therefore lagging indicators of muscle loss rather than leading ones, which is an argument for measuring both.

Mechanically, the regain trajectory after stopping is roughly a mirror of the loss trajectory, and it is not primarily a willpower phenomenon. Appetite signalling returns, energy expenditure remains suppressed relative to the original mass, and the two combine. That is an argument for a maintenance plan existing before the stop, rather than an argument against stopping.

The evidence for a higher protein intake preserving lean mass during an energy deficit is reasonably strong in resistance-trained populations and weaker in sedentary ones, with the meta-analytic estimates supporting intakes in the region of 1.6 g/kg over lower intakes when training is present[1].

One qualification: none of this is a clinical assessment, and unexplained loss of function rather than of mass is a reason to see someone rather than to adjust a programme.

The plateau is arithmetic. Treat it as arithmetic and the response follows.

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LT
answered · acceptedlane_transit42k3819 Feb 2026
5Have you seen anything published on this, or is it inference from the mechanism? – swirl_dont_shake 2 months ago
6Useful. I have added the accept threshold suggestion to my own notes. – dead_volume 4 months ago
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41

Mechanically, what the data supports is narrower than what gets recommended, so it is worth separating the two.

DEXA precision is better than people assume for fat mass and worse than people assume for lean mass in a single scan — the least significant change for regional lean mass on a well-maintained scanner is on the order of a few per cent. That means two scans three months apart can differ without anything having happened, and it means a scan sequence needs to be at least three points before a trend is interpretable.

More usefully, food noise returning is not obviously tolerance. Receptor desensitisation is one hypothesis; a second is that the initial effect was partly novelty and partly the steep early deficit, and a third is that intake has drifted upward and the signal is being outcompeted rather than weakened. The three make different predictions about what a dose increase would do.

The STEP 1 extension reported substantial regain in the year after treatment withdrawal, with weight and cardiometabolic variables trending back toward baseline[1].

I would be careful with the supplement literature here; effect sizes are small, the studies are mostly in trained young men, and generalisation to a large deficit is not obviously valid.

A maintenance plan written before you need it is worth more than a better loss plan.

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DS
answeredDr_Hanne_Solberg40k388 Feb 2026
26

The distinction that resolves this is between proportional loss and functional loss. Losing lean mass in proportion to total mass is what happens in every weight loss intervention. Losing function is not, and function is measurable.

The first four weeks of loss is substantially fluid and glycogen. Each gram of stored glycogen carries roughly three grams of water, and total glycogen is on the order of 400 to 500 g, so the obligatory water shift alone accounts for a couple of kilograms. This is why the first month looks dramatic and the second looks like a plateau when in fact the fat-loss rate has not changed.

Protein target, worked: at 88 kg, a target of 1.6 g/kg is 88 × 1.6 = 141 g per day. Spread across three eating occasions that is roughly 47 g each, and the leucine threshold for a maximal muscle protein synthetic response is met at around 2.5 to 3 g of leucine, which corresponds to roughly 30 to 40 g of a high-quality protein. So three meals at 40 g plus one 25 g snack gets you to 145 g and clears the per-meal threshold each time. On 900 kcal that leaves about 340 kcal for everything else, which is the actual constraint.

Measure strength as well as mass. It is cheaper, it is less noisy, and it is closer to what you actually care about.

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MO
answeredmarta_okonkwo87k2583 Mar 2026
6Good answer, but the confidence interval in the cited trial is wider than implied. – Dr_Rosalind_Achebe 7 months ago
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1

The mechanism is worth having straight, because it predicts which interventions can work and which cannot.

Cardio does not interfere with lean-mass retention at the volumes anyone here is doing; the interference effect in the literature appears at high concurrent volumes in trained athletes. What cardio does at a large deficit is add to the deficit, which is either the point or a problem depending on the objective.

Train, eat the protein, measure something functional, and give the trend three months before you interpret it.

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VI
answeredvialroom87k14814 Apr 2026
-2

A plateau at four to six months is the expected shape of the curve, not a failure of it. Energy expenditure falls with mass, and the deficit closes itself unless intake falls further.

Fibre at very low total intake is a trap. Soluble fibre needs water and motility to work; insoluble fibre adds bulk to a slow transit. At 900 kcal a day with delayed gastric emptying, an osmotic agent is more predictable than a bulking one, and adequate fluid is doing more work than either.

Two resistance sessions a week and a protein target you actually hit will do more than any refinement beyond them.

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TU
answeredtenth_of_a_unit40k3828 Jan 2026

Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.