In these patients, persistently high serum levels of ghrelin (a hormone produced by gastric mucosa which normally stimulates short-term food intake during starvation) play a central role in promoting hyperphagia, increasing appetite, weight gain, and obesity, thus increasing the risk of obesity-related comorbidities such as dyslipidemia [67]. Here, GHRL is linked to obesity due to melanocortin 4 receptor deficiency.