The opioid consumption has exploded in the western world, and for some patient populations such as obese patients, patients with sleep apnoea or patients undergoing cancer treatment, opioid-sparing/ opioid-free strategies could have positive effects on outcomes. Studies suggest that opioids could have opioid-induced immunosuppression, induce chronic post-operative pain syndrome and hyperalgesia in addition to the more well-known side effects such as respiratory depression, nausea, bladder, and bowel dysfunction. Hence, new studies are needed on the impact of person-centered care programs that combine pharmaceutical and non-pharmaceutical strategies to reduce the adverse short and long-term effects of opioid therapy. The overall aim is to evaluate the short-, medium- and long-term effects of opioid-free care pathways with or without person-centred care compared to conventional opioid-based treatment in patients undergoing obesity surgery. Specific aims 1. Determine the effects of opioid-free care with or without person-centred care compared with conventional opioid-based general anaesthesia on the cognitive and physical quality of recovery after surgery up to 24 months after surgery (short-term: postoperative to discharge, medium-term: 14 days, 3 months, long-term: 6 months, 12 months and 24 months). 2. Describe the clinical monitoring trend regarding nociceptive response intraoperatively between opioid-free and conventional care. 3. Map the impact of opioid-free anaesthesia (with and without person-centred care) on the usage of opioids up to 24 months after hospital discharge. 4. Explore the patients' experience of quality of life, self-efficacy and recovery after surgery in opioid-free care with or without person-centred care during the first year post-surgery. The aims will be evaluated by a prospective, randomized, non-blinded, non-commercial multi-centre study (Nov 2018-Dec 2022) approved by the Swedish Medicines Agency (EudraCT 2017003830-97) and the ethical review board (DNR 1006-17).