Blood glucose levels and hormonal response to HPD feeding in the presence and absence of proglucagon-derived peptides. (a) Blood glucose levels in NC-fed control mice (black dots; n = 8), HPD-fed control mice (orange dots; n = 8), NC-fed GCGKO mice (white dots; n = 8), and HPD-fed GCGKO mice (green dots; n = 8) under ad libitum feeding conditions after 1 week of feeding (*** p < 0.001). Plasma concentration of (b) insulin, (c) corticosterone, (d) FGF21, and (e) GIP in NC-fed control mice (black dots; n = 7–8), HPD-fed control mice (orange dots; n = 7–8), NC-fed GCGKO mice (white dots; n = 8), and HPD-fed GCGKO mice (green dots; n = 7–8) after 1 week of feeding (* p < 0.05, ** p < 0.01). Data are expressed as mean ± SEM.