School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. Department of Psychology, Aston University, Birmingham, B4 7ET, UK. P1vital, Manor House, Howbery Park, Wallingford, Oxfordshire, OX10 8BA, UK. Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford NIHR Biomedical Research Centre, Churchill Hospital, University of Oxford, Headington, OX7 3LJ, UK. Centre for Endocrinology, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, B15 2TH, UK. School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. s.higgs.1@bham.ac.uk.