Collecting this in one place because it comes up every few weeks and the answer is always assembled from scratch. It is about protein intake, and it is deliberately narrow — everything I am not confident about is marked as such.
What is actually established
Distribution matters less than total but it is not nothing. Roughly 25 to 40g per sitting with enough leucine to trigger synthesis, three or four times a day, is more effective than the same total in one enormous evening meal — and on a suppressed appetite the enormous evening meal is the one you will not finish anyway.
The condition it depends on
The caveat that reference weight and current weight are different numbers. Using current weight at the start of a large loss produces a target that is both unachievable and unnecessary.
The practical version
The arithmetic that makes it tractable: reference weight in kg times 1.6 gives the target; divide by four for a per-sitting figure; then find four foods that hit that figure in a volume you can actually finish. Most people need two of the four to be liquid or semi-liquid early on.
What I am not sure about
The question I want answered is whether the RDA is the wrong reference entirely during rapid weight loss, and what the actual target should be. Tell me what I have not thought of.
— ChrisMacros · corrections welcome and will be edited into this post with credit