Interpersonal vulnerability, eating behaviours and quality of life in bariatric surgery patients: A systematic review of the relationship between internal weight bias and eating behaviours in bariatric surgery patients; and, An observational study of how interpersonal vulnerabilities, emotional eating, anxiety and depression influence quality of life in patients assessed for bariatric surgery
BACKGROUND: Bariatric surgery is a recommended treatment for people with morbid obesity. Patients who seek or undergo bariatric surgery experience a range of psychosocial difficulties which affect their quality of life, including interpersonal difficulties, maladaptive eating patterns and psychological distress. This thesis aims to investigate how weight-based bias was associated with maladaptive eating patterns in this patient population, and how the interpersonal psychotherapy model of eating disorders (IPT-ED) could be extended to consider the quality of life in those seeking bariatric surgery. METHOD: A systematic review of quantitative studies (n = 11) was undertaken to examine the relationship between internalised weight bias and eating behaviours in bariatric surgery patients. Also, a cross-sectional empirical study examined a pre-existing dataset of routinely collected clinical data from bariatric surgery candidates (n = 193). Drawing on the IPT-ED model, the study used mediation and moderation analyses to explore the relationships between interpersonal vulnerability, anxiety, depression, emotional eating and quality of life. RESULTS: The systematic review found internal weight bias was associated with maladaptive eating behaviours, irrespective of whether patients were seeking or had completed bariatric surgery, and demonstrated medium to large effect sizes. The observational study found emotional eating partially mediated the relationship between interpersonal vulnerability and quality of life in bariatric surgery candidates. Moderation analyses found depression did not moderate the relationship between interpersonal vulnerability and emotional eating in those seeking bariatric surgery, however when anxiety was low interpersonal vulnerability and emotional eating were significantly related. CONCLUSION: Both the systematic review and empirical study demonstrated the strong association between interpersonal vulnerability and eating behaviours (e.g. emotional eating) in bariatric surgery patients. By introducing quality of life to the IPT-ED model and applying it to bariatric surgery candidates it provides clinicians and researchers with an enhanced theoretical foundation to understand how interpersonal factors, eating behaviours and psychological distress combine to affect the psychosocial wellbeing of bariatric surgery patients. Until recently application of theoretical frameworks with this clinical population has been limited. The current study has for the first time shown how an enhanced interpersonal framework featuring quality of life might be applied to those seeking bariatric surgery. Given bariatric surgery is a significant life transition future research would benefit from investigating how this enhanced model evolves at different stages along the patient journey, from pre-surgical assessment through to long-term follow-up.