The effects of RYGB on energy and glucose metabolism still exist in two mouse models of functional GLP-1 deficiency which showed that GLP-1, acting through its classical GLP-1 receptor or its bioactive metabolites, does not seem to be associated with the effects of RYGB on weight loss and glucose homeostasis [107]. Here, GLP1R is linked to hyperinsulinemic hypoglycemia, familial, 4.