Redefining surgical outcomes after metabolic and bariatric surgery: an American Society for Metabolic and Bariatric Surgery narrative literature review of composite response metrics and body composition
In brief
Weight and BMI alone miss important outcomes after bariatric surgery
This narrative review finds that weight and BMI can misclassify response to metabolic and bariatric surgery because they overlook changes in obesity-related diseases, quality of life, and body composition. Composite scores and measures of fat, lean tissue, visceral fat, and bone density offer a broader view, but research must establish how to standardize them and use them in routine care.
- Journal
- Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery (Q1)
- Published
- 5 October 2026
- Study design
- Practice guideline / consensus
- Evidence level
- Level 1, High (CEBM 1c)
- Authors
- Pavlos Papasavas, Faiz Shariff, Sofiane El Djouzi, Colleen Tewksbury, Jonathan Carter, R Wesley Vosburg
- PMID
- 42963217
- DOI
- 10.1016/j.soard.2026.09.019
Why clinicians should know about it
- Picked for Bariatric and Metabolic Surgery (top studies of the week, 1 November 2026): ASMBS review addresses outcome measurement and body composition after bariatric
Abstract
BACKGROUND: Traditional assessment of response to metabolic and bariatric surgery (MBS) has relied predominantly on weight-based and body mass index (BMI)‑based outcomes. However, these measures, which are important to patients, fail to capture important dimensions of treatment response, including changes in body composition, obesity-related diseases, and health-related quality of life. OBJECTIVES: To evaluate emerging approaches that incorporate composite response metrics and body composition assessment as outcome measures after MBS, complementing weight and BMI changes, which may not fully capture clinically meaningful improvements. SETTING: Narrative review conducted by the ASMBS Clinical Issues Committee. METHODS: A narrative review of the current literature was conducted to examine composite outcome measures after MBS and body composition changes. RESULTS: BMI and conventional weight-based outcomes have limitations in assessing response to MBS and may systematically misclassify outcomes across patient populations. Composite measures such as the Bariatric Analysis and Reporting Outcome System, Bariatric Quality of Life Index, and Swiss-Finnish Bariatric Metabolic Outcome Score integrate multiple dimensions of response, including weight loss, improvements in obesity-related disease, complications, and health-related quality of life. Furthermore, body composition assessment provides clinically meaningful information regarding changes in fat mass, visceral adiposity, lean tissue, and bone mineral density that are not captured by BMI or body weight alone. CONCLUSIONS: Response to MBS should not be defined solely by weight or BMI change from baseline. A multidimensional framework incorporating composite outcome measures, patient-reported outcomes, and body composition provides a more comprehensive and patient-centered evaluation of MBS outcomes. Future research should focus on standardizing these measures and evaluating their feasibility for integration into routine clinical practice and outcomes reporting.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.