[1] Volda Univ Coll, Fac Social Sci & Hist, Joplassvegen 1, N-6103 Volda, Norway
[2] More & Romsdal Hosp Trust, Dept Surg, Alesund, Norway
[3] St Olavs Univ Hosp, Ctr Obes Res, Clin Surg, Trondheim, Norway
[4] Norwegian Univ Sci & Technol, Fac Med & Hlth Sci, Dept Clin & Mol Med, Trondheim, Norway
[5] Namsos Hosp, Nord Trondelag Hosp Trust, Clin Surg, Namsos, Norway
[6] St Olavs Univ Hosp, Clin Surg, Norwegian Natl Advisory Unit Adv Laparoscop Surg, Trondheim, Norway
[7] NTNU, Dept Neuromed & Movement Sci, Fac Med & Hlth Sci, Trondheim, Norway
[8] Volda Univ Coll, Fac Arts & Phys Educ, Dept Phys Educ, Volda, Norway
[9] More & Romsdal Hosp Trust, Dept Res & Innovat, Alesund, Norway