Jason Halford is Head of the School of Psychology at the University of Leeds, President of the European Association of Obesity (EASO), and former Chair of the UK Association for the Study of Obesity (ASO). He is a Chartered Health Psychologist. Over the past 10 years his research has focused on drug-induced weight gain, the effects of nutrients and fibre on appetite and hormone release, the effects of stress on eating behaviour, the effect of marketing on children, and on lean-obese differences in the expression of appetite. In 1999, Jason co-founded the Human Ingestive Behaviour Laboratory at Liverpool and in 2004 he also co-founded the Liverpool Obesity Research Network (LORN). Jason is co-ordinator of the SWITCH study, a new trial to examine the impact of artificial sweeteners on appetite in the context of active weight management and is one of the co-ordinating leads for the 9m Euro H2020 SWEET project designed to examine the risks and benefits of using sweeteners to replace sugar