In contrast, there is minimal stimulation of GLP-1 when glucose is infused intraduodenally at rates of 4–8 kJ/min (1–2 kcal/min), but a substantial response at 13–17 kJ/min (3–4 kcal/min) in both healthy individuals and those with type 2 diabetes [12, 29]. This evidence concerns the gene GCG and type 2 diabetes mellitus.