International expert consensus on definitions and management of weight recurrence and suboptimal response after...

Weight recurrence and suboptimal response after metabolic and bariatric surgery (MBS) lack standardized definitions and management approaches, creating barriers to evidence-based treatment decisions and coordinated care across multiple specialties.

To establish international expert consensus on terminology, diagnostic approaches, and management strategies for suboptimal response and weight recurrence after MBS.

International Delphi study across multiple countries and health care systems.

A two-round modified Delphi study was conducted with 66 international experts across five specialties (MBS, obesity medicine, gastroenterology, endocrinology, dietetics and nutrition, and psychology). A 164-item questionnaire was developed, spanning seven dimensions: conservative management, diagnostic methods, endoscopic interventions, quantitative thresholds, risk factors, surgical interventions, and terminology. Consensus was defined a priori as ≥70% agreement. Inter-rater reliability was assessed using Gwet's AC1 coefficient.

Response rates were 54.5% (Round 1) and 57.6% (Round 2). Consensus achievement improved significantly between rounds (26.2% to 40.9% of items). Experts reached unanimous agreement on core management principles including individualized patient care (100%) and the appropriateness of specialists prescribing antiobesity medications (100%). Strong consensus emerged on standardized terminology with "suboptimal" as the preferred term (89.5%) and %TWL as the optimal measurement approach (94.6). For quantitative thresholds, consensus was achieved on surgical nonresponse defined as <10% TWL at 12 months (73.0%), recurrent weight gain as >25% of lost weight from nadir (70.3%), and a 10% change in %EWL from nadir as normal physiologic response (83.8%). Conservative management items achieved the highest consensus rates (80.9%) while quantitative threshold items require additional research (28.1%). Inter-rater reliability improved across all domains, with conservative management achieving substantial agreement (AC1 = .70).

Expert consensus was achieved on fundamental principles of postbariatric care, including preferred terminology, measurement metrics, and provider roles. These recommendations address important gaps in clinical practice standardization.