Luca Lotta1, Claudia Langenberg1, Nicholas J Wareham2, I Sadaf Farooqi3. 1. University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK. 2. University of Cambridge MRC Epidemiology Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK. Electronic address: nick.wareham@mrc-epid.cam.ac.uk. 3. University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK. Electronic address: isf20@cam.ac.uk.