The primary aim of this investigation is to assess the concentrations of fibroblast growth factor 21 (FGF-21), sortilin, meteorin-like protein (Metrnl), and nesfatin-1 in individuals with obesity, regardless of the presence of carbohydrate metabolism abnormalities, within the context of metabolic syndrome. Here, FGF21 is linked to obesity due to melanocortin 4 receptor deficiency.