1. Division of Gastroenterology, Hepatology, and Nutrition; The Children's Hospital of Philadelphia; Philadelphia PA USA
2. Center for Clinical Epidemiology and Biostatistics; University of Pennsylvania School of Medicine; Philadelphia PA USA
3. Center for Weight and Eating Disorders; University of Pennsylvania School of Medicine; Philadelphia PA USA
4. The Department of Child and Adolescent Psychiatry and Behavioral Sciences; The Children's Hospital of Philadelphia; Philadelphia PA USA