PREVALENCE OF METABOLIC SYNDROME (MS) IN CHILDREN AND ADOLESCENTS WHO CONSULT WITH OBESITY Background: The higher prevalence of  childhood obesity has led to search for MS in this age group. Aim: To study the prevalence of MS in obese children and adolescents. Material and methods: Cross sectional study of 255 obese children and adolescents aged 11.3±2.4 years, 45% males, 60% pubertal, with a body mass index (BMI) z score of 2.7 ±0.6, who were evaluated for obesity. MS was defined as the  presence of at least three of the following criteria, according to Ferranti: fasting glucose (FG)?100 mg/dl, triglycerides (TG)?100 mg/dl, HDLpercentile (p)75 and blood pressure (BP)> p90. Patients were also classified using Cook criteria: FG?100 mg/dl, TG?110 mg/dl, HDLp90, BP>p90. Results: MS was observed in 45 and 22.7% of patients, according to Ferranti and Cook definitions, respectively. WC was the most frequent criteria and glucose was the most uncommon. Males had higher body mass index, WC and TG levels than females. According to  Ferranti and Cook definitions, MS prevalence was 53.5 and 28% in males and 37.6 and 18.4% in females (p