Expert panel proposes common measures for weight recurrence after bariatric surgery

What happened

A multinational expert panel has proposed a common vocabulary for describing weight outcomes that fall short of expectations after metabolic and bariatric surgery. The work used a modified Delphi process, a structured method in which specialists rate statements over repeated survey rounds.

The researchers invited 66 professionals from surgery, obesity medicine, endocrinology, gastroenterology, nutrition, dietetics, and psychology. They evaluated 164 statements across seven topics, including terminology, diagnosis, risk factors, conservative care, endoscopic care, surgical care, and numerical definitions. A statement needed support from at least 70% of respondents to qualify as consensus. Thirty-six invitees completed round one and 38 completed round two.

The group favored percent total weight loss as the main postoperative measure. At 12 months, its suggested boundary for nonresponse was a total weight reduction below 10%. It also supported defining recurrent gain as regaining more than 25% of the greatest weight reduction reached after surgery. Agreement for those two thresholds was 73.0% and 70.3%, respectively, placing each just above the study's consensus boundary.

Broader management principles drew stronger support than many numerical or procedural statements. The respondents unanimously agreed that care for nonresponse or renewed gain should be individualized. They also agreed that an obesity specialist may appropriately include anti-obesity medication in a patient's management plan.

What it means

Clinicians and researchers have used different labels, formulas, and time points for the same postoperative pattern. Shared definitions could make clinic notes, studies, and referrals easier to compare. They may also help a care team distinguish an expected fluctuation from a trend that deserves assessment.

The proposed cutoffs are reference points rather than moral judgments. A person's current health, lowest postoperative weight, operation type, medications, nutrition, symptoms, and goals remain relevant when deciding what evaluation or support is appropriate.

What it does not mean

A Delphi study measures agreement among participating experts. It does not prove that a chosen cutoff predicts complications, determines the best intervention, or improves long-term outcomes. The two numerical definitions barely cleared the prespecified 70% line, which signals less uniformity than the unanimous recommendation for individualized care.

Only about half of the invited panel completed each survey round. The result therefore represents the specialists who responded, not every profession, country, program, or patient. The paper also does not turn a threshold into an automatic indication for medication, endoscopy, or revision surgery.