55 obese adolescents (12-18y, BMI > 95th percentile) were randomly allocated to one of three 12-weeks diet regimens: low-carbohydrate low-fat, low-carbohydrate high-fat or balanced low-fat diet, followed by 9-months follow-up. Weight, Height, waist circumference, lipid profile, glucose, insulin, liver enzymes, renal functions, C-reactive protein, leptin, ghrelin and resting energy expenditure were measured in the morning after over-night fast at baseline, during the 12-weeks of intervention and after 9-months of follow-up.