Simon is Professor of General Practice at the University of Cambridge, Group Leader in the Medical Research Council Epidemiology Unit and CEDAR (the UKCRC Public Health Centre of Excellence for Diet and Activity Research), Honorary Professor of General Medical Practice at Aarhus University Denmark, Honorary Doctor of Umea University Sweden, Honorary Consultant at Cambridge University Hospitals NHS Foundation Trust, assistant General Practitioner at Lensfield Medical Practice and fellow of Wolfson College. He qualified from the London Hospital Medical College in 1986. He was the first principal in general practice to be awarded a Wellcome Trust Fellowship during which he trained in Clinical Epidemiology and Public Health at the University of Southampton and the London School of Hygiene and Tropical Medicine. He leads a research programme which contributes to efforts aimed at preventing the growing burden of diabetes, obesity and related metabolic disorders by translating epidemiological knowledge into preventive action, and evaluating the effectiveness of a range of preventive approaches in randomised trials. He published the first diabetes risk score and the first trial of screening for type 2 diabetes. He has completed over 30 trials and (co)authored over 300 publications which have been cited over 15,000 times.