Department of Surgery, King Hussein Cancer Centre, Amman, Jordan. National Obesity Treatment Centre, Hamad Medical Corporation, Doha, Qatar. Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK. Department of Medicine, Manchester University NHS Foundation Trust, Manchester, UK. Department of Diabetes and Endocrinology, Salford Royal NHS Foundation Trust, Salford, UK. Department of Diabetes and Endocrinology, Hamad Medical Corporation, Doha, Qatar. Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar.