In Japan, more than 70% of patients with T2DM are being treated with DPP‐4 inhibitors and ~60% of drug‐naïve patients receive DPP‐4 inhibitors as the first‐line treatment.11 In view of recent reports demonstrating positive effects of nutrition and diet on incretin hormones such as GLP‐1,12 we hypothesize an IDEP (Interaction between Diet/Exercise and Pharmacotherapy) concept by comprehensive literature review. Here, GCG is linked to type 2 diabetes mellitus.