This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
I read post #27 twice before replying, because I had assumed the opposite.
For anyone finding this later: the short answer on 18-month record is that it depends on one thing, and the rest of the thread is people identifying which thing.
That is a fair summary of where the discussion has got to.
Practical note on 18-month record: write down what you expect before you look. The number of times I have found what I went looking for is higher than chance would allow.
A single scale used throughout beats a more accurate scale introduced halfway through. Consistency beats accuracy for a trend.
That matches what I was told, which is not the same as knowing it.
Adding the boring version of 18-month record, because the interesting version keeps getting posted and the boring one is usually right.
Check the ordinary explanations, in order, and stop when one of them accounts for what you are seeing. Most of the time the second one does.
Plateaus and resets: if weight loss stalls and then resumes, that is ordinary. It is not evidence that the medication stopped working. It is not evidence that it is still working either. It is a data point in a longer record.
Speaking for myself and not for anyone else who has posted here.
Taking post #38 at face value and following it one step further.
I think the 18-month record question is answerable and has not been answered, which is a more optimistic position than most of this thread.
18-month record would be much easier to settle if anyone reported the denominator. Almost nobody reports the denominator.
Narrowing post #44, because the general version has more than one answer.
A note on scope: what I am saying about 18-month record applies to the case in the first post and I would not extend it further without checking.
Everything in post #46 holds. The case it does not cover is the one I have.
Menstrual cycle: for people who menstruate, weight can shift by several pounds across the cycle due to fluid retention and other factors. Noting cycle phase when weighing reduces apparent noise.
Medication changes: escalating dose, or adding or removing other medications, can affect the rate of weight loss. Documenting medication changes alongside weight makes the record interpretable.
Take the reasoning and check the arithmetic; I do not always get it right.
That is a cleaner way of putting what I was circling around.
Post #53 put the caveat in the right place and I want to underline it.
Self-reported intake is optimistic in a consistent direction, and saying so in your own report is more credible than not.
Building on post #53 rather than restating it.
18-month record was covered in the wiki last year and the page has a review date on it, which is a better starting point than my memory of a thread.
On 18-month record, I would rather understate and be corrected upward than overstate and be quoted. That is a house style here and it is a good one.
Nothing here is medical advice and a progress report is a description of what happened to one person under uncontrolled conditions.
No disagreement from me. Posting only so the question does not look ignored.