How bariatric surgery performs over GLP-1s in weight loss

Learn how effective bariatric surgery is for treating weight loss when compared to GLP-1s so you can make the right choice about your health!   

By Craig L. Floch, MD, Associate Medical Director of Bariatric Surgery, Nuvance Health, part of Northwell Health  

Obesity is common around the world. Because of this, doctors and researchers are looking for better ways to help people lose weight and stay healthy. Obesity is a long-lasting and complicated disease, so it needs more than just simple solutions.  

Two important ways to treat obesity today are bariatric surgery and GLP-1 receptor agonists (GLP-1 RAs), a type of medicine. Both options have helped many people lose weight, but it is important to compare how they work, how well they help people lose weight, what side effects they may have and how much they cost.  

This article explains these treatments in a way that will help you make the best choice for your health.  

Learn more about Nuvance Health's comprehensive weight loss program 

How obesity treatments are changing weight loss medicine  

Obesity is not just about eating too much. It can be affected by genes, the foods around us, how active we are and our habits. Obesity can cause problems like diabetes, high blood pressure, high cholesterol, sleep troubles and fatty liver disease. At first, doctors told people to eat healthier and exercise more. Now, there are medicines and surgeries that can help even more. Each treatment has its own pros and cons. 

Types of bariatric surgery 

Bariatric surgery is a group of operations that can help people lose a lot of weight. These surgeries can also improve or even cure health problems that come with obesity. The two most common surgeries are sleeve gastrectomy and Roux-en-Y gastric bypass. 

• Sleeve gastrectomy: In this surgery, about 80% of the stomach is removed, leaving a smaller tube-shaped stomach. This means the person feels full sooner. The surgery also lowers a hunger hormone called ghrelin, helping people feel less hungry.
• Gastric bypass: This operation makes a small stomach pouch and connects it straight to the small intestine, skipping a big part of the stomach and intestine. This helps with weight loss because food goes a different way in the body. It also changes hormones that help people feel full and affects the stomach bacteria in a good way, leading to greater weight loss and better control of blood sugar. 

Both surgeries can help people lose a lot of extra weight and keep it off for many years. 

Related content: Is bariatric surgery right for you? 

GLP-1 receptor agonists  

GLP-1 receptor agonists are medicines that act like a natural body chemical called GLP-1. These medicines help people lose weight in a few ways: 

• Helping the body use sugar: They help the pancreas make insulin only when it's needed, which means they don’t usually cause low blood sugar.
• Lowering other hormones: They lower a hormone called glucagon, helping the liver make less sugar.
• Slows the emptying of stomach: This helps people feel full longer after eating.
• Reducing hunger in the brain: They make people feel less hungry, so they eat less. 

Some main GLP-1 RA medicines for weight loss are liraglutide, semaglutide and tirzepatide. Tirzepatide also affects another hormone for better results. 

Related content: Trizepatide or Semaglutide weight loss drugs explained 

Comparing long-term weight loss: surgery versus GLP-1s 

Doctors and patients often wonder which treatment works better for weight loss. Research shows that surgery usually leads to more and longer-lasting weight loss than medicines like GLP-1s, alone. 

How much weight can you lose and for how long? 

Studies comparing both weight loss surgery and the use of GLP-1s show that surgery can lead to about two to three times more weight loss than using GLP-1medicine alone, making it the strongest tool for major weight loss at this time. 

• Bariatric surgery: People usually lose about 25% to 35% of their starting body weight after Roux-en-Y and about 20% to 30% after sleeve gastrectomy in the first year. Most people keep much of this weight off for many years.
• GLP-1s: People taking the highest doses of semaglutide can lose about 15-17% of their body weight in a little over a year. With tirzepatide, weight loss can reach about 21-22%. Still, this is not as much as with surgery, and it is harder to keep the weight off if you stop taking the medicine. 

Healing health problems related to obesity 

Losing weight can help fix or improve other health problems caused by obesity. Both weight loss surgery and GLP1 treatments help with problems like diabetes, high blood pressure and sleep apnea but surgery often has bigger and longer-lasting benefits. 

• Type 2 diabetes: Bariatric surgery, especially gastric bypass, can cause diabetes to go away in 60% to 70% of people for a long time, even before all the weight is lost. GLP-1s also help lower blood sugar and sometimes put diabetes into remission, but not as often or for as long as surgery does.
• Other conditions: Both treatments help improve blood pressure, cholesterol, sleep problems and fatty liver disease. Because surgery leads to more weight loss, these other conditions usually improve even more than with GLP-1 medicines. 

Related content: Discover foods that boost metabolism and promote weight loss 

Safety and side effects of using GLP-1s 

Knowing about possible risks helps patients and doctors make the best treatment choices. 

Risks of bariatric surgery 

• Short-term risks: Leaks at connection sites, bleeding, infection and blood clots. Death is a risk of any surgery, although it’s a very low risk.
• Long-term risks: People might have problems like vitamin or mineral shortages, so they need to take supplements, stomach ulcers, hernias, new or worsening heartburn or need more surgeries to fix problems. 

Side effects of GLP-1s 

• Common side effects: The most frequent problems are upset stomach, feeling sick, vomiting, diarrhea or constipation. These issues might go away over time but can bother some people enough to stop taking the medicine.
• Rare but serious side effects: Serious but rare side effects include pancreas inflammation, gallstones or kidney problems (sometimes from losing too much fluid). There is a warning about a certain type of thyroid cancer in animals, but it's not clear if this happens in people. There have also been a few cases of severe stomach slowing (gastroparesis). Since these medicines must be taken long-term, side effects can add up over time. 

Surgery usually has bigger, short-term risks, while GLP-1s usually have milder, long-term side effects, mostly linked to the stomach and gut. 

Who should have bariatric surgery vs. GLP-1 treatments? 

Both weight loss surgery and GLP-1 treatments work best when part of a bigger weight management plan that includes support from doctors, advanced practice providers, dietitians and mental health counselors. Deciding who gets which treatment is important for keeping people safe and healthy. 

Who qualifies for bariatric surgery? 

Guidelines suggest surgery for: 

• People with a body mass index (BMI) of 40 or higher.
• People with a BMI of 35 or higher who also have other serious health problems from obesity such as diabetes or obstructive sleep apnea.
• Some newer guidelines say it’s okay for those with a BMI as low as 30 if their type 2 diabetes is hard to control.  

At Nuvance Health, all patients have a full check-up, including with a psychologist to make sure they are ready for the changes surgery brings. 

Who qualifies for GLP-1s? 

These medicines are usually for: 

• People with a BMI of 30 or higher.
• People with a BMI of 27 or higher who also have weight-related health problems. Doctors usually suggest using these medicines as part of a full plan that also has advice on food, exercise and healthy behaviors. 

Related content: The truth behind common nutrition myths 

The importance of healthy habits for weight loss 

Neither surgery nor medicine may be enough on their own. Both are most successful when combined with eating healthy, being physically active and making long-term changes in habits. After surgery, people must follow eating rules, take vitamins and get regular check-ups. People on GLP-1 RAs also get the best results when they include healthy eating and exercise. 

Related content: 5 best exercises for weight management 

Costs and long-term value of weight loss treatments  

It is important to understand your insurance plan, what is covered by insurance and what you are responsible for paying out-of-pocket before proceeding with any weight loss treatments. Some health systems and hospitals, like Nuvance Health, offer financial assistance programs for qualifying individuals. Ask your care team for more information so you can better understand the cost of treatments. 

Weight loss treatment cost savings and society 

Studies show that, over time, surgery often saves money because it helps people take less medicine for other diseases and lowers trips to the hospital. Even though the initial cost is high, preventing illnesses like diabetes and sleep apnea saves money later. GLP-1 RAs help with these problems too, but the high ongoing price for the medicine can reduce the savings. Helping people be healthier also helps them feel better and work more, which is good for society as a whole. 

Considering surgery for weight loss? Book now with a bariatric surgeon. 

Combining weight loss treatments and looking ahead 

Doctors are learning that mixing different treatments or choosing the right one for each person often works better than just picking one option for everyone. 

• Using both together: Some people might use GLP-1 RAs before surgery to lose weight and lower risk, or after surgery if they start gaining weight again or need extra help with health problems.
• Personalized plans: The best obesity care might mean picking the right treatment for each person. Some might do best with medicine, others with surgery, depending on their weight, health and goals.
• New research: More medicines and treatments are being studied. More head-to-head studies are needed to see which options work best, especially over many years. 

Learn more about nutrition counseling at Nuvance Health.  

The bottom line: Both bariatric surgery and GLP-1 receptor agonists are important tools to treat obesity and the diseases it can cause. Right now, surgery leads to more weight loss and greater improvement in other health problems, but it may come with higher risks and costs at first. Medicines may have fewer risks because they don’t require surgery, but they may not lead to as much weight loss and must be taken for a long time. Either way, big lifestyle changes are needed to keep the weight off and stay healthy.  

The best choice depends on each person’s situation and doctors, nurses and other health professionals can help people decide what is right for them. In the future, mixing treatments and making plans that fit each person promises even better results for people living with obesity. 

Ready to take control of your weight this summer? Book now with a bariatric medicine specialist and start your journey to better health.