Professor Stephan Rossner MD PhD was Professor of Health Behavior Research at the Karolinska Institute in Stockholm and Director of the Obesity Unit at the Karolinska University Hospital. He has worked with international obesity-related matters for more than twenty years and served as the Secretary, Vice-President, and President of the International Association for the Study of Obesity (IASO). He has published more than 500 scientific articles on nutrition and lifestyle-related matters, written more than twenty books for the lay press, appeared repeatedly in media, and promoted health as a stand-up comedian in ‘science theatre’.