Stephan Rössner (born 3 April 1942) is a Swedish physician. He is Professor in Health Related Behavioral Science at Karolinska Institutet in Stockholm, working at the Department of Medicine at the Huddinge campus of the Karolinska University Hospital.[1] He has written several books on the issue and is the leading member of Viktklubben (the Weight Club) at the tabloid Aftonbladet.