FTR, I don’t follow the OP’s reasoning. At all. Also, to be fair, I don’t think that English is his first language.
However, isn’t it reasonable to imagine that that for everything there is a point of diminishing returns, a point where more stops being better and more still becomes counter productive or even harmful? It’s certainly true with training, total calories etc. I have only the most basic understanding of human biology myself, so forgive my ignorance but, I am curious.
Regarding “residue”: I’m not sure what OP was referring to, but what about free radicals, urea and other waste products of digestion and cellular metabolism? As far as I know increased LBM doesn’t increase our kidneys’ ability to excrete urea, and while I doubt that this is really harmful in someone with healthy kidney function it is another process our organs must undergo and every process causes strain/more waste products. As for free radicals, I think we can agree that they contribute to inflammation, catabolism, accelerated aging, disease etc and other things we generally aren’t too keen on.
Unfortunately, free radicals seem to be produced every time our bodies utilize oxygen. As far as I know, oxidation takes place when the body converts amino acids into cellular energy and thus free radicals result. Consequently, higher demands are placed on our bodies stores of antioxidants. Also, as an aside, the more muscle tissue one has, the more metabolic processes are underway at any given time and so the more free radicals are being produced. Obviously not arguing against having muscle, just a thought.
Another demand “excess” protein intake places on the body is that the body must use buffering agents to maintain ph balance which must be tightly controlled at all times. This process may or may not be harmful in the long term, but it still bears considering. Another issue would be the digestive demands of processing proteins down to amino acids and simply moving large quantities of flesh through the intestines (I am unsure how much we can really assimilate at a sitting although I am familiar with the rules of thumb).
There is obviously an enzymatic and energy cost associated with this that should be considered when trying to figure the net benefit of consuming protein beyond a certain quantity. As far as I know our bodies can’t store excess protein. Amino acids are converted into molecules that are either used (inefficiently) for energy or preferably synthesized into new tissue and the rest is just excreted. Increasing protein intake, again as far as I know, does not increase the rate at which our bodies can utilize amino acids for protein synthesis, provided an adequate quantity is available. However, our bodies must still process and eliminate all that we take in thus incurring the attending metabolic costs, regardless of whether it benefited us at all.
What I’m driving at in this ridiculously long post (sorry) is that, given the metabolic, financial, and ultimately ecological cost of food in general and protein specifically in this case, doesn’t it bear considering where the point is at which we are getting the maximum benefit (relative to our goals) from the minimum amount of food?
Those nano-tubes are a bitch too.