[1] Univ Manchester, Sch Med Sci, Manchester, England
[2] Northern Care Alliance NHS Fdn Trust, Salford Royal Hosp, Diabet Endocrinol & Obes Med, Manchester, England
[3] Univ Manchester, Fac Biol Med & Hlth, Manchester, England
[4] Northern Care Alliance NHS Fdn Trust, Salford Royal Hosp, Oesophago Gastr & Bariatr Surg, Manchester, England
[5] Univ Salford, Manchester, England