It is known that plasma lipid levels are controlled not only by dietary fat and carbohydrate but also by dietary protein and amino acids.
Although it used to be thought that the source of protein was important, it is known that amino acid composition, amino acids themselves,
and peptides from digested protein are more important than the protein source…
…Deprivation of total amino acids or single, essential amino acids resulted in a rapid decrease
in the rate of protein synthesis, which was readily reversed by re-addition of the deficient amino acid(s).…
Link to Source:
American Journal of Cell Physiology
Deficiency or imbalance of essential amino acids in the diet may produce profound depression of immune responses
and apparent, marked changes in the immune resistance of the host animal to tumors.…
Link to Source:
Journal of Experimental Medicine
…the proportion of rp mRNAs residing in polysomes was two- to fivefold less in rats fed diets lacking
tryptophan, leucine, or BCAA compared with rats fed the control diet.…
Link to Source:
National Center for Biotechnology Information
Decreased rates of protein synthesis which occurred in rat livers perfused with amino acid-deficient medium were accompanied by a loss of polysomes and a doubling of concentrations of ribosomal subunits and monomers as compared to unperfused liver or livers perfused with amino acid-supplemented medium.
Thus, deprivation of essential amino acids not only directly and rapidly represses global mRNA translation, but also potentially results in a reduction in the capacity to synthesize protein.
Link to Source:
The Journal of Nutrition
Regulation of Global and Specific mRNA Translation by Amino Acids
…The results suggested that, when rats were fed a protein-free diet, methionine is the first limiting amino acid for liver protein synthesis.…
These results indicated that, under meal-feeding condition which may be considered more a physiological condition than force-feeding, the deficiency of
BCAAs (branched-chain amino acids) are indispensable (essential) amino acids that are required for body protein synthesis. Indispensable
amino acids cannot be synthesized by the body and must be acquired from the diet…Twenty amino acids are required for protein synthesis.