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.
Two things can be true about fibre intake at once: the mechanism is plausible and the evidence for the size of the effect is thin. Most of the argument here is people defending the first against attacks on the second.
Where I part company with post #28, and it is a narrow parting.
Where intake has fallen a long way, protein is usually the first thing to fall because it is the least appealing macronutrient when appetite is reduced.
Where somebody reports losing strength, intake and training stimulus are the first two things to look at rather than the compound.
Somebody will have a better source than mine, and I hope they post it.
Renal considerations around higher protein intake apply to people with existing renal impairment and are frequently generalised beyond that population.
This has been discussed before and I could not find the thread, so, again.
I had written a reply contradicting post #32 and deleted it. Here is what survived.
Fibre intake is one of those subjects where the general answer and the answer for a specific case diverge, and the thread will go in circles until someone says which one is being asked for.
Right, and stated more narrowly than I would have dared to state it.
Density matters more than quantity when total intake is limited. The same protein in a smaller volume is the whole game.
It is worth checking rather than assuming, which costs nothing.
Fibre and fluid tend to fall alongside protein when intake drops, and the constipation reported here follows from that as much as from the mechanism.
It reads as pedantry until the day it does not.
Eating anything at all: on substantial appetite suppression, eating enough total calories to maintain lean mass is the priority. Protein comes second to total intake.
I have left out the parts I could not verify.
The arithmetic in post #41 is right; the assumption feeding it is the part to check.
Self-reported intake is optimistic by a consistent margin in the published comparisons, which is worth applying to your own numbers.
Post #41 put the caveat in the right place and I want to underline it.
On fibre intake I would separate what is worth knowing from what is worth acting on. The first list is long and the second is short, and conflating them is how threads get heated.
Counterpoint on fibre intake, offered without confidence: the same observation is consistent with a much duller explanation, and nobody has ruled the dull one out.
Fibre: adequate fibre intake supports fullness and gut motility, both of which matter during the gastrointestinal effects of these compounds. High fibre on top of appetite suppression requires attention to hydration and gradual introduction.
Someone should write this up properly, and it should probably not be me.
Where I part company with post #45, and it is a narrow parting.
Where intake has fallen a long way, protein is usually the first thing to fall because it is the least appealing macronutrient when appetite is reduced.
Protein targets during weight loss: the standard recommendation is 1.6 to 2.2 grams per kilogram of body weight. Individual requirements vary but that range is a reasonable starting point.
This is the version I would want a new member to read first.
Post #50 answers the question as asked. The question underneath it is different.
Leucine and MPS: leucine stimulates muscle protein synthesis at a threshold of roughly 2 to 3 grams per meal. That influences how much protein per meal matters, but total daily protein still matters most.
The mechanism is not mysterious. Substantial energy restriction with inadequate protein and no resistance stimulus loses lean tissue as well as fat.
If this contradicts something upthread, the upthread version may well be the better one.
Fibre intake 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.
Practical experience of fibre intake, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.
What I want from this fibre intake thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.