Obesity is a serious and common problem in childhood and adolescence. Being overweight as a child or teenager is associated with increased morbidity and mortality as an adult. Obese children and adolescents manifest the same metabolic risk factors (e.g. insulin resistance, hyperinsulinemia and lipoproteinemia) as obese adults. This study proposed testing the hypothesis that fenfluramine and phenetermine are safe and effective in weight loss and prevention of weight gain in adolescent patients. However, this study was terminated after publication of negative effects of the treatment.