David S. Ludwig, MD, PhD is a practicing endocrinologist and researcher at Boston Children’s Hospital. He holds the rank of Professor of Pediatrics at Harvard Medical School and Professor of Nutrition at Harvard School of Public Health. Dr Ludwig is Founding Director of the Optimal Weight for Life (OWL) program at Children's Hospital, one of the country’s oldest and largest multidisciplinary clinics for the care of overweight children. He also directs the New Balance Foundation Obesity Prevention Center. His research focuses on the effects of diet on hormones, metabolism and body weight. In particular, he developed a novel “low glycemic load” diet (i.e., one that decreases the surge in blood sugar after meals) for the treatment of obesity and prevention of type 2 diabetes and heart disease. Dr. Ludwig is Principal Investigator on numerous grants from the National Institutes of Health, has published over 150 scientific articles, and presently serves as Contributing Writer for JAMA. He is author of the forthcoming book, Always, Hungry? Conquer Cravings, Retrain your Fat Cells, and Lose Weight Permanently (Grand Central Publishing, January 2016).