David L. Katz MD, MPH, FACPM, FACP is a nationally recognized authority on nutrition, weight control, and the prevention of chronic disease. He is Adjunct Associate Professor of Public Health Practice, and formerly the Director of Medical Studies in Public Health, at the Yale University School of Medicine. Dr. Katz directs the Yale Prevention Research Center, which he co-founded in 1998. Dr. Katz has published over 100 scientific articles and chapters; innumerable abstracts, newsletter articles, health columns, and essays, and eleven books to date. Dr. Katz is formerly a medical contributor for ABC news, the nutrition columnist to O, The Oprah Magazine, an on-line expert blogger for Prevention Magazine, and a syndicated health/nutrition columnist for The New York Times. He is also a frequent contributor of expert opinion on nutrition and obesity to publications including The Wall Street Journal, The Washington Post, The Chicago Tribune, The Boston Globe, HealthDay News, and The Associated Press. The visionary behind the NuVal™ Nutritional Scoring System, Dr. Katz convened and led the 12-member scientific panel that developed the ONQI™ (Overall Nutritional Quality Index) algorithm that powers the NuVal System. Dr. Katz also is the Chief Science Officer for NuVal LLC and liaison to the independent Scientific Advisory Board that oversees the ongoing management of the ONQI algorithm.