Hormones that control hunger, satiety, obesity, glucose, and maintain weight include leptin, ghrelin, cholecystokinin (CCK), oxyntomodulin (OXM), glucagon-like receptor-1 (GLP-1), insulin-like peptide-5 (INSLP-5), and peptide YY (PYY). Here, GCG is linked to obesity due to melanocortin 4 receptor deficiency.