David S. Ludwig, MD, PhD, is a practicing endocrinologist, researcher, and professor at Harvard Medical School and Harvard School of Public Health. He received a PhD and an MD from Stanford University School of Medicine and completed an internship and residency in pediatrics and a fellowship in pediatric endocrinology at Boston Children's Hospital. Dr. Ludwig also directs the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital. His research focuses on the effects of diet on hormones, metabolism and body weight. 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-related diseases. In addition, his group has done some of the original studies linking sugar-sweetened beverages and fast food to excessive weight gain, heart disease and type 2 diabetes. Described as an “obesity warrior” by Time magazine, Dr. Ludwig has fought for fundamental policy changes to restrict junk food advertising directed at young children, improve the quality of national nutrition programs, and increase insurance reimbursement for obesity prevention and treatment. Dr. Ludwig is Principal Investigator on numerous grants from the National Institutes of Health, has published over 150 scientific articles, and served for 10 years as Contributing Writer for JAMA. He has also written several books for the public, including 'Ending The Food Fight' (2007), 'Always Hungry?' (2016) and the cookbook 'Always Delicious' (2018).