Research findings have confirmed that branched-chain amino acids (BCAAs), including isoleucine, leucine, and valines as well as aromatic amino acids such as phenylalanine and tyrosine are involved in pathways of insulin resistance, including fatty acid oxidation, mTOR, JNK and IRS1 pathways and also T2D [38]. Here, IRS1 is linked to type 2 diabetes mellitus.