Roger Lentle graduated in medicine and in biochemistry from University College London and gained his PhD at Massey University, New Zealand. He has published extensively on the physical processes of digestion and is Professor of Digestive Biomechanics at the Institute of Food Nutrition and Human Health at Massey University. Patrick Janssen gained his PhD in chemical and process engineering at Canterbury University, New Zealand. He worked in the fields of process control and milk fat processing in the dairy industry before developing an interest in the physical processes of digestion. Currently he is a senior lecturer at the Institute of Food Nutrition and Human Health at Massey University.