The health impact of diet and physical activity may play a part in the marked ethnic differences in type 2 diabetes and cardiovascular disease in the UK, according to research reported at the London School of Hygiene & Tropical Medicine. In the Pemberton Lecture at the 2012 Meeting of the Society for Social Medicine, Professor Peter Whincup of St George’s, London University, also said that social class has a big effect on health - but not in the same way for all ethnic groups. He explained to Peter Goodwin why the study of ethnicity and health is needed to help reduce inequalities such as a six-fold difference in the incidence of diabetes between communities in the same city. .