Dr. Vallis is a health psychologist based in Halifax, Canada. He is a Health Behaviour Change Consultant and Associate Professor in Family Medicine at Dalhousie University. He obtained his Ph.D. and M.A from the University of Western Ontario, London, and his B. Sc. From Dalhousie University. His main area of expertise is adult health psychology, with an emphasis on obesity, diabetes, cardiovascular risk and gastroenterology. He spends most of his time training healthcare providers in behaviour change for chronic disease management. He regularly supervises clinical and academic students and is active in research on motivation, behavioural change and adaptation to chronic disease. He consults nationally as well as internationally and is heavily involved in academic publications, journal editing, and clinical practice guidelines. He was on the executive of the Canadian Clinical Practice Guidelines for the Management of Obesity (2020) and lead author of the Psychological and Behavioural Chapter for these new guidelines as well as the 2006 guidelines. As well, he is an author of the Psychology and Mental Health chapter of Diabetes Canada’s Clinical Practice Guidelines (2018, 2013, 2004). He received the 2021 Charles H Best award from Diabetes Canada and was awarded a Queen’s Diamond Jubilee Medal by the Government of Canada on the recommendation of the Diabetes Canada.