claudia_zurich said:

Order of operations matters more than any single choice here: establish a baseline, change one thing, wait long enough for it to express itself, then…

Adding the part of the answer the thread has not reached. Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the correction. That is slower than asserting, and it is the only version that survives being wrong.

The figures, for anyone assembling their own picture. Practical: whatever you change, write down the date and the reason. In three months the reason is what you will have forgotten, and the reason is what makes the record worth having.

Following on from claudia_zurich — and this may be the naive question:

How would you tell the difference between that and the alternative explanation?

Dr.GutHealth said:

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

Pushing back on Dr.GutHealth here. Pushing back on the anecdote-stacking. Twenty people reporting the same thing is twenty samples from the same self-selected pool, not twenty independent confirmations.

That is the short version; the long version is somebody else's post.

Dr.GutHealth said:

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

Right, and the exception is worth naming rather than left implied, because the exception is where people get into trouble.