Every letter we have printed

What I would most like to see is a piece on what has not been measured. Duration beyond the trial periods, composition after regain, and the effect of a second loss cycle are all open, and the absence of data is itself worth reporting.

A short note on reporting. Where a study reports training volume, it should report it in a form somebody could reproduce: sessions, exercises, sets and progression. Most report a duration in weeks and nothing else.

Resistance training during an energy deficit attenuates lean tissue loss rather than preventing it, and the honest framing is attenuation. Overstating what training can achieve sets an expectation that the evidence does not support and that people then blame themselves for missing.

Distribution across the day has a modest evidence base and it is a great deal weaker than the total. Presenting the two as equally established is a common error in popular summaries and it displaces attention from the number that matters.

Hydration state, recent exercise and time of day all move these estimates, and serial scans done under different conditions are not comparable. Standardising the conditions is free and it is the single largest improvement available to anybody tracking themselves.

I have been reading this department since the first issue and it remains the only coverage of this trade I would put in front of a colleague.

Panels sold direct to consumers are assembled for marketing as much as for clinical use, which is why they are long. A shorter panel repeated on a schedule is more informative than a long one taken once.

Deciding in advance what would change a decision is the discipline missing from most self-arranged testing. A test that cannot change anything is a purchase rather than a measurement.

Haemolysis is the commonest artefact and it is visible to the laboratory, which is why the comment on the report matters more than any individual value. Several analytes are unusable in a haemolysed sample and the report says so if you read it.

Where a result is flagged high or low, the flag is generated by software against the interval and carries no clinical judgement whatsoever. Readers treat the flag as an opinion and it is a comparison.

Your piece assumes readers have a clinician ordering panels for them. A great many of us are buying our own, from services that supply an interval, a flag and nothing else. The apparatus you describe is not available to us at all.

Desensitisation kinetics differ between ligands at the same receptor, which is a well-established property of this family and almost absent from the popular account. A compound that resists desensitisation behaves differently over weeks regardless of its acute potency.

Comparison tables in this area are assembled from papers that used different assays, different cell lines and different readouts, and the resulting column of numbers looks like a measurement series. It is a collection of unrelated measurements formatted as one.

The endogenous ligand is degraded within minutes and the compounds under discussion are not, which is the whole engineering story and the part most worth explaining to a general reader. Everything else follows from that one design decision.

Your treatment of biased signalling is careful, which I appreciate, because the literature is not. Reduced beta-arrestin recruitment producing less receptor internalisation is a plausible mechanism for sustained signalling, and the step from that to a clinical claim is longer than most summaries admit.

Your piece states that moving the injection day does not change total exposure, and I accept the arithmetic, but I want to record that it changed my experience considerably. I moved from Monday morning to Thursday evening and the two worst days now fall on a weekend. The drug is doing the same thing; my week is not.

A small thing: you write "class B GPCR" and then "secretin-like receptor" as though these were different classifications. They are the same family under two naming conventions, and the piece would be clearer if it said so.

Compensatory adaptation over weeks is the systematic limit on any acute mechanistic account, and it is not measurable in the assays that generate the mechanistic claims.

The accountability gap is contractual rather than analytical. Nobody in the chain has warranted anything to the buyer, so a wrong figure has no consequence, and a system with no consequence for error will produce errors at whatever rate is convenient.

What happens when a certificate turns out to be wrong is the question your article stops short of. In a regulated setting a corrected document is reissued to everyone who received the original. Elsewhere it is corrected for whoever complained, and the original stays in circulation. That asymmetry is worth a piece of its own.

Storage conditions on a certificate should describe what the material was stored under before the determination, not what the buyer ought to do afterwards. The second is advice, the first is data, and the two are printed in the same box.

The lot number is the thread that holds a custody claim together, and it is frequently absent from the vial itself. Where the label carries only a molecule and a strength, there is nothing to connect the sample to any document at all.

Sealed does not mean unopened. A crimp seal can be lifted and replaced by anybody with the right tool, and the visual check most buyers perform would not detect it. Tamper-evident and sealed are different properties sold under one word.

Publication bias applies here as much as anywhere. A blind programme that publishes only its interesting findings has a denominator problem, and readers have no way to reconstruct the denominator from the outside.

The unit confusion in this area is a design problem rather than an education problem. A syringe graduated for one purpose, used to measure a volume of something else, will produce errors at a rate determined by the markings and not by the diligence of the person reading them.

The stated content of a vial is the assumption everything else rests on, and it is exactly the quantity this publication has shown is least often independently determined. The arithmetic can be perfect and still produce the wrong answer.

I have accumulated about eighteen months of used needles in a plastic tub because I did not know where to take them and assumed I would be asked questions. Your paragraph on this is the first time I have seen the situation described rather than lectured about.

Reconstituting with the wrong volume and then calculating from the intended volume is the second error, and it is invisible afterwards because the vial looks identical. Writing the actual diluent volume on the vial with a marker takes three seconds and closes it.

The pieces I have found most useful are the ones that concluded nothing very much. Reporting the absence of a finding is a service and it does not read as one at first.

Divergence between practice and label is used as an argument in both directions and supports neither. That people do something differently is a fact about people, and it carries no information about whether it works.

The material this publication covers has no label at all, which makes the whole comparison a read-across from a different product. Saying so plainly, as you do, is more useful than the comparison itself.

The plateau discussion in community settings has a strong survivorship character. People whose trajectory continued do not post about a plateau, so the visible discussion overstates how universal the experience is.

The tolerability curve and the efficacy curve have different shapes, and the interesting region is where they diverge. Almost all discussion of ceilings addresses one curve at a time.

Adherence typically falls over the course of a long trial, and a falling adherence curve will produce a flattening outcome curve without any change in response. The two are rarely plotted together.

Vitamin D and calcium status are collected in some of these protocols and reported in almost none, despite being obvious effect modifiers. Where the data exists, publishing it would cost nothing.

The precision of the instrument, the magnitude of the reported change and the duration of the study should always be given together. Any two of the three without the third leaves the reader unable to judge whether anything was measured at all.

I am sixty-eight, I have lost nineteen kilograms over fourteen months, and my consultant has twice told me my lean mass is fine on the basis of a handheld bioimpedance device in the clinic corridor. Having read your piece on what that device measures, I am no longer sure what I have been reassured about.

Re-titration after an interruption is the question I am asked most often and the one with the least published guidance. The pharmacokinetic reasoning is straightforward: after several half-lives the exposure has gone, and resuming at the previous dose is resuming without the accommodation that produced tolerance.

The length of the interruption must matter and no threshold has been established anywhere. Advice that specifies a duration is specifying a number nobody has measured.

Your piece treats the four-week step as arithmetic, and I accept the arithmetic, but my prescriber moved me up every two weeks and I reached the top dose without difficulty. I do not think the schedule is as constraining as you suggest.