[1] Chelsea & Westminster Hosp, Bariatr Surg Serv, London SW10 9NH, England
[2] CNWL NHS Fdn Trust, Psychol Med Unit, London SW10 9NG, England
[3] Phoenix Hlth, Chester, Cheshire, England
[4] Univ Coll London Hosp, NHS Trust, Ctr Weight Management Metab & Endocrine Surg, GI Div, 250 Euston Rd, London NW1 2PG, England
[5] Massachusetts Gen Hosp, Weight Ctr, Boston, MA 02114 USA
[6] Harvard Univ, Sch Med, Boston, MA USA
[7] Barts Hlth NHS Trust, Community Hlth Serv Div, Tower Hamlets Adult Weight Management Serv, London, England
[8] Luton& Dunstable Univ Hosp NHS Trust, Obes & Bariatr Serv, Luton, Beds, England