This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Post #30 is the version of this I will quote in future. One addition.
The most useful protocol is the one you will actually repeat identically. An imperfect measurement repeated consistently beats a better one repeated carelessly.
That is the version I use. It may not be the version that is correct.
Report the method with the number, always. A composition figure without the method is not comparable to anything, including your own previous figure.
That is clearer than the version I had in my head. Thank you.
On bioimpedance and hydration, 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.
Posting my bioimpedance and hydration numbers with the method attached so they can be discounted properly. Uncontrolled, unblinded, and collected by someone who wanted a particular answer.
On bioimpedance and hydration, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is the interesting bit.
If you can post the two or three numbers you are working from, several people here will check the arithmetic rather than argue about the conclusion.
The arithmetic in post #41 is right; the assumption feeding it is the part to check.
I would rather this thread reach "we do not know" about bioimpedance and hydration than reach a confident answer that nobody can support when asked.
Post #41 put the caveat in the right place and I want to underline it.
Photographs under fixed lighting and posture are a genuine record and are the hardest of these to standardise.
What would change my mind on bioimpedance and hydration is a second dataset collected by someone with no stake in the first. Until then I hold it loosely and I would rather say so than pretend to more.
Where I part company with post #45, and it is a narrow parting.
Standardise the conditions: same time of day, same hydration, same recent training, same machine. Most of the variability is protocol rather than physiology.
That matches what I was told, which is not the same as knowing it.
Marking my place. If it changes for me I will come back and say so.
I read post #45 twice before replying, because I had assumed the opposite.
I disagree with the framing of bioimpedance and hydration above, and I think it is a substantive disagreement rather than a terminological one. Setting out why, so it can be checked.
The reasoning depends on an assumption that is doing a lot of work and is never stated. If the assumption holds, the conclusion follows. I do not think it holds generally.
Source for the bioimpedance and hydration figure, since it was asked for. It is in the discussion rather than the abstract, which is why the version circulating is stronger than the paper is.
Reading the surrounding paragraph is worth the two minutes. The authors are more careful than their summarisers.
The documentation on bioimpedance and hydration is better than this thread and I say that as someone who has posted in the thread.
Something worth flagging about bioimpedance and hydration: the strongest-sounding claims in this thread are the ones with no source attached, which is the usual pattern and not a coincidence.
If you are new and reading this thread for the answer to bioimpedance and hydration: the answer is conditional, the conditions are in the third reply, and the rest of the thread is worth skipping.
Post #54 put the caveat in the right place and I want to underline it.
The most useful protocol is the one you will actually repeat identically. An imperfect measurement repeated consistently beats a better one repeated carelessly.
I had written a reply contradicting post #58 and deleted it. Here is what survived.
Bone mineral density changes with substantial weight loss are measurable and slow, and are one of the better reasons to have a baseline scan.
It is one reading of the data and not the only reasonable one.