[1] Imperial Coll London, Dept Surg & Canc, London, England
[2] Imperial Coll, Dept Metab Digest & Reprod, London, England
[3] Univ Hosp Southampton NHS Fdn Trust, Div Surg, Southampton, Hants, England
[4] Imperial Coll London, Hammersmith Hosp, Div Psychiat & Computat, Dept Brain Sci,Cognit & Clin Neuroimaging Lab, London, England
[5] Imperial Coll London, Imperial Clin Trials Unit, Dept Publ Hlth, London, England
[6] Imperial Coll London, Dept Brain Sci, Cognit & Clin Neuroimaging Lab, Psychiat & Computat Cognit & Clin Neuroimagin Lab, London, England
[7] Univ Coll Dublin, Diabet Complicat Res Ctr, Dublin, Ireland
[8] King Saud Univ, Coll Appl Med Sci, Dept Community Hlth Sci, Riyadh, Saudi Arabia
[9] Univ Southampton, Southampton Hlth Technol Assessment Ctr, Southampton, Hants, England
[10] Imperial Coll London, Sect Nutr Res, Dept Metab Digest & Reprod, London, England
[11] Kings Coll Hosp NHS Trust, Dept Endocrinol, London, England
[12] Univ Hosp Southampton NHS Fdn Trust, Biomed Res Ctr, Southampton, Hants, England
[13] Univ Southampton Med Sch, Primary Care, Population Sci & Med Educ, Southampton, Hants, England