Weight loss surgery can produce major results when GLP-1 medicines do not

A Cleveland Clinic study found that people who lost little weight on semaglutide or tirzepatide often went on to lose far more after bariatric surgery. The findings may provide another option for patients with severe obesity who get only modest benefit from these medicines or find the side effects hard to tolerate.

The research examined outcomes over a two-year period after surgery. For patients who had not responded well to medication, gastric bypass produced greater weight loss than sleeve gastrectomy, which was the other procedure included in the analysis.

Although both drugs can support weight loss, results differ from person to person. As use of these treatments expands, doctors and patients are increasingly weighing what to do when the first option does not work well.

Published in Annals of Surgery, the study reviewed records from 4,929 adults who had surgery at Cleveland Clinic hospitals between 2018 and 2024. All of the patients had a body mass index of at least 35, a level used to identify more severe obesity.

Among those patients, 207 had lost too little weight while taking semaglutide or tirzepatide, and 61 had stopped the drugs because of side effects. The other 4,661 had not used either medication before surgery and served as a comparison group.

Before surgery, the researchers estimated that the inadequate-response group had lost about 1.5% of body weight over two years. Those who could not tolerate the medicines were estimated to have gained 1.4% during that same period.

After surgery, the outcome changed sharply. In the group that had not lost enough weight on medication, the estimated two-year weight loss was 32.7% of starting weight after gastric bypass and 17.8% after sleeve gastrectomy, after adjustments for measurable differences.

Patients who stopped the drugs because of side effects also lost substantial weight after surgery. Their estimated two-year losses ranged from roughly 20% to 28%, depending on the procedure and whether they had type 2 diabetes.

Sleeve gastrectomy removes a large portion of the stomach and leaves a smaller, tube-shaped pouch. Gastric bypass creates a small stomach pouch and reroutes food farther down the small intestine, altering how the digestive tract processes food.

The researchers reviewed care that had already occurred, so patients were not randomly assigned to surgery or to one specific operation. People chosen for bypass may have differed from those selected for sleeve in ways the records did not fully capture.

The study focused on weight change, which is only one part of the decision-making process that also involves surgical risk and long-term follow-up. Still, it offers clear evidence that an unsuccessful attempt with either drug can be followed by significant weight loss after surgery.

If you are interested in this topic, please read articles about More People Combine Weight Loss Drugs with Surgery to Fight Obesity, and Surgery or New Weight Loss Drugs Which Protects Your Heart Better.

Source: Cleveland Clinic.