Adding the clinical framing, because it changes how the question reads. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.

If somebody has the primary source to hand I would rather cite it than paraphrase it.

TirzTom said:

Practical: whatever you change, write down the date and the reason.

Thank you — that is the clearest version of this I have read, and I have read a lot of them. I will report back once I have actually tried it.

Adding the clinical framing, because it changes how the question reads. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.

Dr.GastroMayo said:

The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either.

This matches mine closely enough to be worth saying so. The mechanism that matters here is not stomach emptying, it is central. GLP-1 receptor agonism in the arcuate nucleus stimulates POMC neurons and suppresses AgRP/NPY signalling, which is why the effect is appetite and food salience rather than physical fullness. Delayed gastric emptying largely tachyphylaxes over the first months; the appetite effect does not.

I would rather be corrected than agreed with, if it comes to it.

Moderator note: a couple of off-topic posts removed.