These benefits following RYGB, in particular, may be at least partly attributed to the reduction of glucogenic amino acids methionine and aspartate that can affect insulin action, as well as a decrease in phenylalanine and tyrosine, the aromatic amino acids associated with impaired insulin secretion [61] that are the earliest predictors for future risk of T2D [39]. Here, INS is linked to type 2 diabetes mellitus.