INS and type 2 diabetes mellitus: Although the biologically plausible mechanisms for the adverse effects of high intakes of proline and glutamic acid on diabetes risk are less known, our findings regarding high-proline amino acid patterns support those of previous studies, which reported that high exposure to this amino acid may cause an impairment in insulin transcription and mitochondrial oxidative phosphorylation and consequently contribute to the β-cell dysfunction observed in type 2 diabetes [24].