GCG and obesity due to melanocortin 4 receptor deficiency: AMPK signalling activator in peripheral organs is considered to be a promising candidate anti-obesity agent due to its activation stimulating muscle and hepatic mitochondrial biogenesis and fatty acid oxidation [63]; however, contrary to peripheral organs, in the central nervous system, activation of AMPK signalling in the hypothalamus enhances the secretion of glucagon, corticosterone, and epinephrine, resulting in the activation of hepatic gluconeogenesis and glycogenolysis [64].