Cannabis use jumped 52% after weight-loss surgery, and people drinking hazardously were most likely to start

Post-bariatric surgery cannabis use rose from roughly 10.5% to 16%, a 52.4% relative increase. Of those using cannabis after surgery, 45.9% had not used before. Hazardous alcohol use tripled the odds of both initiating and continuing cannabis use post-operatively.

Cross-sectional survey of 612 patients who had metabolic and bariatric surgery (MBS) between 2018 and 2021 at a single Michigan health system. Participants completed online surveys about cannabis, alcohol, and other substance use, psychiatric symptoms, and demographics.

Bariatric surgery patients are known to sometimes shift addictive behaviors after the procedure. This is one of the first studies to document how cannabis use specifically changes around surgery, which matters as cannabis becomes more accessible in legal states.

This fits into growing research on "addiction transfer" after bariatric surgery, where patients sometimes replace food-related behaviors with substance use. Understanding cannabis as part of this pattern is increasingly relevant in states with legal access.

Single health system in a legal-cannabis state limits generalizability. Self-reported data subject to recall bias. Cross-sectional design cannot establish causality. No control for specific surgical procedures or weight loss outcomes.