GLP1R and obesity due to melanocortin 4 receptor deficiency: Interestingly, double incretin receptor knockout (DIRKO) and glucagon‐like peptide‐1 (GLP‐1) receptor KO mice (Glp1r‐/‐) also showed resistance to diet‐induced obesity, despite a significant increase in food intake in the GLP‐1 receptor KO mice (Drucker, 2003; Hansotia, 2004; Hansotia et al., 2007).