The trend is what I care about; individual weeks are obviously noise.
I have a result I cannot explain, and I would rather diagnose it than guess.
I have checked the obvious explanations and eliminated the two easiest ones.
What is the most likely explanation, and how would I confirm it?
Answer first: a plateau is almost always the arithmetic catching up rather than the intervention failing, and the arithmetic changes because you are smaller.
Maintenance energy requirement falls with body mass. Losing fifteen kilograms reduces it by roughly two to three hundred kilocalories a day for most people, which is enough to close a moderate deficit entirely without any behaviour changing.
The correct instrument is a rolling average of daily weights, not a weekly single reading. Daily variation of a kilogram either way is normal and swamps a real weekly change.
Adaptive thermogenesis beyond that predicted by mass loss is documented in metabolic-ward and doubly labelled water studies and persists for years in some cohorts.
Four weeks of trend data before you call it a plateau. Ten days is noise.
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
Shop standardsThe short version: reduced maintenance requirement, adaptive thermogenesis and drifting intake, in that order of magnitude.
Water retention masks fat loss on a timescale of weeks. Glycogen repletion, sodium changes and menstrual cycle phase can each hide a kilogram or more of genuine loss.
Diet breaks — a fortnight at maintenance — have modest evidence for improving adherence and none for accelerating loss, which is still a reason to consider them.
Self-reported energy intake is underestimated by twenty per cent or more in doubly labelled water comparisons, consistently across populations.
Measure intake honestly for a week before changing anything.
edited 23 Apr 2026 by v_ramaswamy — tightened the wording; no substantive change
The relevant physiology is that a smaller body costs less to run, so the same intake that produced a deficit is now maintenance.
Intake drift is real and invisible: portion sizes creep, untracked items accumulate, and self-reported intake is systematically underestimated even by people who are trying hard.
Adaptive thermogenesis adds a further reduction beyond what mass predicts — commonly cited at 10 to 15 per cent of resting expenditure after substantial loss — and it persists for a long time after the loss itself.
Weight-loss trajectory in the major trials in this class flattens around the nine-to-twelve-month mark, which is the expected shape rather than a failure of the intervention.
Your maintenance requirement fell because you did. Recalculate rather than escalate.
The honest answer is that plateaus are expected, that they resolve, and that the response is patience plus measurement rather than escalation.
Escalating the deficit is the intuitive response and the wrong one: it increases the lean fraction of loss and reduces adherence at the same time.
Diet-break protocols show adherence benefits in randomised comparisons without a consistent effect on total loss.
Trajectories flatten in every trial in this class. That is the shape, not a failure.
Put another way, weight is a noisy signal with a large water component; a four-week moving average is the right instrument.
A four-week flat trend with honestly measured intake is a genuine plateau. Anything shorter is not enough data to act on.
The caveat is that reducing intake further is not always the right response and can be actively counterproductive.
Use a rolling average. Single weigh-ins are not a signal.
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.