IRS1 and Insulin resistance: Serum valine, as one of the BCAAs, has been consistently identified to be an important metabolite associated with insulin resistance in previous epidemiologic studies [33–37], probably through inhibition of insulin receptor substrate-1, and a recent study has reported that increased serum BCAAs probably produce more catabolic intermediates including propionyl CoA and succinyl CoA, resulting in accumulation of incompletely oxidized fatty acids and glucose [38].