Research

Observational study compares GLP-1 medicines with bariatric surgery in routine care

The two-system analysis found long-term weight differences, but treatment was not randomly assigned.

What happened

A study in Obesity retrospectively analysed 44,025 adults with BMI of at least 35 who received semaglutide, tirzepatide, sleeve gastrectomy or gastric bypass across two urban health systems.

What we know

Surgery was associated with larger weight changes at one, two and three years in the observed groups. The authors compared clinical records rather than randomly assigning treatments.

Limitations

Groups may differ in severity, eligibility, medicine continuation, access and follow-up. An observational association cannot establish which option is better for an individual and does not capture every risk or clinical goal.

Why it matters

The study helps frame routine-care expectations and persistence. Surgery and pharmacotherapy are different interventions and should not be reduced to a single weight figure.