Dan Waitzberg is a gastrointestinal surgeon and nutrologist. He received his medical degree from the University of São Paulo (FMUSP), Brazil in 1974 and completed his residency in surgery at the Hospital das Clínicas, of the same university, in São Paulo in 1977. Dr. Waitzberg obtained his Masters and PhD in surgery from the University of São Paulo, where he also became an Associate Professor from the Department of Gastroenterology in 1991. Dr. Waitzberg is the Director of Short Bowel Syndrome Ambulatory, Clinical Director of Nutrition Service, Founder and Director of Nutrology Residence at Hospital das Clinicas, University of São Paulo Medical School. In addition, he has been Director of the Laboratory of Investigation in Metabolism and Nutrition in Digestive Surgery at FMUSP and Founder and amd Director of GANEP –  Nutrição Humana (www.ganep.com.br) since 1981.  In GANEP he developed several educational programs in clinical nutrition for the classroom and the internet (www.ganepeducacao.com.br) including the yearly conference Ganepao (www.ganepao.com.br).  In addition he is the Head of the Nutritional Support Team at the Institute of Cancer of the State of Sao Paulo (ICESP) and Hospital Santa Catarina. He is the Scientific Director of the Free Eeducational Portal of Clinical Nutrition for Health Practitioners ( www.nutritotal.com.br) since 1991, with 65 thousand registered members.  His main research area is clinical and experimental nutrition, with special interest in inflammation, microbiota, molecular biology, and enteral and parenteral therapy, particularly immunonutrition and omega-3 fatty acids, in the context of malnutrition, surgery, obesity and cancer. He is member of several clinical nutrition societies all over the world and serves as a member of several editorial boards and has published over 130 articles in peer-reviewed journals, 120 in non peer reviewed journals, more than 260 book chapters and 10 books.