06/20/2025
Researchers from New York University (NYU) compared sleeve gastrectomy and gastric bypass operations against semaglutide or tirzepatide. These drugs are known as glucagon-like peptide-1 (GLP-1) receptor agonists, because of the way they mimic the natural GLP-1 hormone, which controls appetite.
Using health records, the team matched people who had taken one of the weight loss drugs with people who had undergone either of the bariatric surgery operations, based on age, body mass index, and blood sugar levels.
The bottom line: people in the surgery group shed an average of 25.7 percent of their total body weight over two years, while those in the medication group lost 5.3 percent.
That’s partly down to patients not sticking to their GLP-1 drugs, whereas surgery is more permanent, but the researchers also noticed smaller differences over shorter time frames – the surgery always gave the best results.
“Clinical trials show weight loss between 15 percent to 21 percent for GLP-1s, but this study suggests that weight loss in the real world is considerably lower even for patients who have active prescriptions for an entire year,” says Avery Brown, a surgical resident at NYU Langone Health.
