"Efficacy in Adolescents of Continued Behavior Modification Following a Six Month Sibutramine-based Weight Management Intervention"

Inclusion Criteria: * Age: \> or = 12 and \< or = 18 years old at the time of screening * BMI that is at least more than the U.S. weighted mean of the 95th percentile based on age and sex * Willing to lose weight to meet and continue study medication for the 12 month treatment period even if he/she meets personal weight loss goal. * Willing to not start any new weight loss products * Males or non-pregnant females (pregnancy determined by self-report) * Females of childbearing potential if practicing acceptable method of contraception Exclusion Criteria: * Weight loss ≥ 10 pounds in previous 3 months * Active gastrointestinal disorders (except GERD) such as peptic ulcer disease, irritable bowel disease, and gallbladder condition (in last 3 months); inflammable bowel disease (Crohn's ulcerative colitis, celiac sprue) * At least 2 out of 3 blood pressure readings either systolic or diastolic ≥ 95%ile for height and age or pulse ≥95 beats per minute at initial visit. * Drug treated diabetes mellitus or drug treated hypertension * Drugs and/or supplements administered for the first time or withdrawn during the past 6 months which have a significant impact on body weight or digestion (see Appendix D) * Inability or unwillingness to comply with protocol requirements, i.e. considered to be unfit for study participation, or unable to swallow pills. * Unwilling to avoid consumption of alcoholic beverages * Smoking or has started a smoking cessation program within the past six months * Previous treatment with prescription sibutramine (Meridia®) * History of recurrent nephrolithiasis * Major psychiatric or eating disorders (i.e., major depressive disorder, bipolar disorder, anorexia nervosa, bulimia or laxative abuse) * Kidney, liver, or thyroid disorder * Drugs that are contraindicated with concomitant use of sibutramine (Meridia®) within last 4 weeks (See Appendix E) * Cardiovascular disease (including arrhythmias, heart failure or congenital heart defect * History of bleeding problems, hemophilia * History of migraine headaches; seizures; a stroke or mini-stroke * History of Pulmonary hypertension * Osteopenia or osteoporosis * Self-report of current recreational drug use or overused prescription medications * History of glaucoma * Females who self-report pregnancy