Previous work by Greenfield and colleagues has shown that 30 g of oral glutamine in 300 ml water can stimulate increases in GLP-1 and insulin in healthy and obese volunteers and patients with type 2 diabetes [7] with mean peak GLP-1 concentrations of around 22 pmol/l (72 pg/ml) in lean healthy volunteers. This evidence concerns the gene INS and type 2 diabetes mellitus.