GLP1R and obesity due to melanocortin 4 receptor deficiency: Studies have demonstrated that gastrointestinal hormones, such as ghrelin, orexin, glucagon-like peptide-1 (GLP-1), and leptin, can regulate feeding behavior, energy homeostasis, etc. (Cameron and Doucet, 2007; De Silva and Bloom, 2012).Numerous studies have shown that GLP-1 receptor agonists have good clinical efficacy in the treatment of diabetes and obesity (Han et al., 2017).