Professor of Global Public Health at the University of Bath. Previously senior clinical research fellow at the London School of Hygiene and Tropical Medicine, and adjunct professor of public health at University College Cork, University of Agder, and the Western Norway University of Applied Sciences. Senior strategic adviser on obesity to Public Health England. Founder director of the National Obesity Observatory for England 2007-2011, led the development of the English National Child Measurement Programme childhood obesity surveillance system, chaired the NICE Programme Development Group (PDG) for guidance on measures to promote walking and cycling, was a member of the NICE PDG on preventing obesity, sat on the management group of the Foresight Obesities project and the Department of Health Expert Panel on obesity, and sit on several WHO Europe steering groups. Currently involved in research assessing the social and environmental factors influencing both obesity and physical activity, and the role of evidence and policy in influencing complex system problems.