The main findings of the present study were: (i) adolescents with MetS exhibited higher values of WC and HC, as well as elevated BMI, FM, triglycerides, fasting insulin, and HOMA-IR compared to their peers without MetS; (ii) FFM (%) and high-density lipoprotein cholesterol (HDL-C) were protective factors for MetS; (iii) higher BMI z-scores, HOMA-IR, and resting CHO were identified as significant risk factors for the development of MetS. Here, INS is linked to metabolic syndrome.