Donald E. Greydanus, MD, DrHC (ATHENS), FAAP, FSAM (Emeritus), FIAP (H) is Professor, Founding Chair, and Pediatric Residency Program Director, Department of Pediatric and Adolescent Medicine at the Western Michigan University Homer Stryker M.D. School of Medicine (Kalamazoo, Michigan USA). He is also Professor of Pediatrics and Human Development at Michigan State University College of Human Medicine (East Lansing, Michigan, USA) and Clinical Professor, Department of Pediatrics at Michigan State University College of Osteopathic Medicine. He is an international leading expert in adolescent medicine and health, who has published numerous scientific papers and books as well as received many national and international awards for his work.