In HFD obese rat stomach, ex vivo incubation of the fundus fragments with IBMX (Supplementary Fig. 4) still significantly increased the GLP-1 release, but in the antrum, this GLP-1 release was not significantly reduced, suggesting an overall reduction of gastric GLP-1 release in response to obesity condition. Here, GLP1R is linked to obesity due to melanocortin 4 receptor deficiency.