We need to eat differently – for the planet and our own health too. This much is becoming increasingly clear as report after report shows that cutting emissions from the agri-food system hinges on dietary change. But what determines our food choices, and what are the lessons for policy makers, health, education, food companies, retail, and the wider food system? Prof Charlotte Hardman, Psychologist of Eating Behaviour in the Department of Psychology, Institute of Population Health, at the University of Liverpool, sheds some light on this important topic.