Both Ac-ghrelin and obestatin levels were analyzed in obese subjects with or without MetS; among them, Ac-ghrelin levels were found to be significantly lower in obese children with MetS compared to obese children without MetS (22.65 (14.9–64) pg/mL vs. 60.0 (22.04–70.0) pg/mL, respectively) (p < 0.01). This evidence concerns the gene GHRL and metabolic syndrome.