BackgroundPreoperative health optimisation for elective surgery entails supporting patients to improve their health in preparation for their treatment and recovery. While there is consensus that this process should address obesity, approaches vary across England. Despite guidance from the National Institute for Health and Care Excellence to the contrary, restrictive approaches with body mass index thresholds for referral to arthroplasty are in use. This qualitative study aimed to investigate the views of professionals on the current use and future implications of these policies.MethodsSemi-structured interviews were conducted with 20 professionals including clinicians, commissioners, policymakers, and health service managers, with experience of developing and/or implementing health optimisation policies for elective arthroplasty. Participants were sampled from areas in England with and without restrictive policies. We undertook thematic analysis of the interview data.ResultsParticipants described pre-surgical health optimisation as an important trigger for health improvement but identified current resourcing and inadequacies in provision of weight management support as significant barriers to success. Participants expressed concerns about the appropriateness and fairness of including obesity as a determinant to restrict access to surgery. They described short-term financial pressures underlying the use of restrictive body mass index thresholds and a lack of an evidence base, such that policies amounted to rationing and risked exacerbations of health inequalities. The study identified four priorities for improvements to future health optimisation practices: developing and implementing national guidance with flexibility for local variation, initiating patient engagement in primary care with onward integration across all services, improving resourcing to support effective equitable impact, and addressing wider determinants of obesity through societal change.ConclusionsOverall, participants had limited expectations of the impact of health optimisation policies on obesity without additional support, investment, and national guideline implementation. They raised strong concerns over current restrictive approaches. We conclude that addressing concerns around weight management support service availability and impacts on health inequalities is essential for shaping effective health optimisation policies. Future policy direction should support health optimisation to be offered early (ideally in primary care). Health optimisation interventions should be non-restrictive, inclusive, and well-monitored, particularly around equality impact.