Clinical perspective, offered as context rather than as advice. Worth answering the question that was asked rather than the one behind it. The narrow version usually has an answer; the broad version usually does not, and answering the broad one is how a thread stops being useful.

DanielChem_CHI said:

The boring version of this is the one that works, and the boring version is: measure a baseline, change one variable, wait, measure again under the…

This is exactly what I could not find anywhere else. I will report back once I have actually tried it.

Adding the clinical framing, because it changes how the question reads. The distinction that resolves most of these threads is between what is true on average and what is true for one person. Both are real; they answer different questions and get quoted as if they were the same one.

Dr.ObesityLA said:

The distinction that resolves most of these threads is between what is true on average and what is true for one person.

This matches mine closely enough to be worth saying so out loud. Posting only so the count is not one.

Moderator note: a post naming a supplier has been edited. Discuss suppliers in the review sections, not here. Thread quality here is what the rules are for. Keep it up.