Circulating levels of FGF21 are increased in subjects with obesity [14], dyslipidemia [15], metabolic syndrome [14], diabetes mellitus [16], nonalcoholic fatty liver disease, coronary artery disease [17], atherosclerosis [18], acute myocardial infarction [19], diabetic nephropathy [20], and arterial hypertension [21]. This evidence concerns the gene FGF21 and obesity due to melanocortin 4 receptor deficiency.