1. Imperial Weight Centre, Imperial College Healthcare NHS Trust, St Mary’s Hospital, Praed Street, London W2 1NY, UK
2. Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, Hammersmith Hospital, 6th Floor Commonwealth Building, Du Cane Road, London W12 0NN, UK
3. Imperial College School of Medicine, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
4. Department of Surgery and Cancer, Imperial College London, St Mary’s Campus, Praed Street, London W2 1NY, UK