W. Allan Walker, MD, is a Professor of Pediatrics at Harvard Medical School and the Director of the Division of Nutrition at Harvard Medical School. He also holds a host of other positions, including Visiting Scientist, Massachusetts Institute of Technology, faculty Member, Division of Medical Sciences, Harvard Medical School, Conrad Taff Professor of Nutrition, Harvard Medical School, Professor, Department of Nutrition, Harvard School of Public Health, Chief, Pediatric Gastrointestinal and Nutrition Unit, Combined Harvard Program Children's Hospital and Massachusetts General Hospital, and Physician, Boston's Children's Hospital. He has won many awards for his work, including the top nutrition award from the American Academy of Pediatrics.