Keith Frayn is Emeritus Professor of Human Metabolism at the University of Oxford, UK. In a long and varied career studying human metabolism and nutrition, he has worked in various settings from diabetes clinics to Accident and Emergency departments and Intensive Care wards. His work has been widely recognised with awards including the first Blaxter Medal of the Nutrition Society, the David Cuthbertson Lecture at the European Society of Parenteral and Enteral Nutrition, and Honorary Fellowship of the Nutrition Society.