Protein Absorption in Older Folks
I did a search in the forum and didn't see this addressed so I'm asking for any input here. I've seen it said over and over that older folks don't absorb or process protein as efficiently anymore.
Which is it, absorb or process?
If it's absorption, why then do people say you absorb all the protein you eat (in response to someone quoting the "only so much protein can be absorbed" myth) and don't sh*t it out?
If it's process, what would the body do with extra protein it couldn't use towards muscle repair/building?
Is there actual scientific study behind all this?
I'm not looking for an amazingly long/deep explanation nor do I want to waste anyone's time with any arguments. I'd just really like to know if there really is science behind these claims, or even if it's something we know because of evidence in populations and if so can someone show it to me?