Preoperative educational interventions in bariatric surgery: a systematic review and meta-analysis

Preoperative educational interventions in bariatric surgery are structured programs combining information, skills training, and behavioral support delivered before metabolic and bariatric surgery and are increasingly incorporated into surgical pathways. However, these interventions vary substantially in content, intensity, and mode of delivery, and their efficacy on clinically meaningful outcomes remains uncertain. Therefore, this study aimed to systematically evaluate the effects of preoperative educational interventions on weight-related, functional, metabolic, and surgical outcomes in patients undergoing bariatric surgery. A systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials evaluating structured preoperative educational interventions were included. Meta-analyses using random-effects models were performed where appropriate. Outcomes unsuitable for quantitative pooling were synthesized narratively. Risk of bias was assessed using Risk of Bias 2, and intervention reporting was evaluated using the Template for Intervention Description and Replication checklist. Thirteen randomized controlled trials were included. A meta-analysis showed that preoperative educational interventions were associated with a clinically meaningful reduction in preoperative body mass index compared with standard care. However, this pooled estimate was highly heterogeneous, driven primarily by a single very-low-calorie-diet trial. A significant absolute reduction in 30-day postoperative complications was also observed. Exercise-based interventions improved functional capacity, as measured by the 6-minute walk test, although heterogeneity was substantial. Dietary interventions did not consistently improve postoperative anthropometric outcomes, whereas cognitive-behavioral interventions primarily influenced behavioral rather than weight outcomes. Eating behavior measures demonstrated consistent directional improvements, whereas evidence on metabolic outcomes was limited and fragmented. Because such interventions are already embedded in many state-of-the-art bariatric programs, the priority is not broad adoption but standardization of intervention content, identification of the specific components that drive clinically meaningful benefit, and evaluation of longer-term outcomes.