Obesity is a complex, chronic disease influenced by a combination of genetic predispositions, environmental factors, medication use, and individual lifestyle choices. For individuals struggling with obesity, bariatric surgery and medications like GLP-1 receptor agonists offer viable treatment avenues. Weight loss surgery, also known as bariatric and metabolic surgery, reflects the impact of these operations on patients’ weight and the health of their metabolism (breakdown of food into energy). In addition to their ability to treat obesity, these operations are very effective in treating diabetes, high blood pressure, sleep apnea and high cholesterol, among many other diseases. These operations also have an ability to prevent future health problems. Today’s metabolic and bariatric operations have been refined over the course of many decades and are among the best studied treatments in modern medicine. They are performed with small incisions using minimally invasive surgical techniques (laparoscopic and robotic surgery). These advancements allow patients to have a better overall experience with less pain, fewer complications, shorter hospital stays and a faster recovery.
Bariatric Surgery vs. GLP-1s: An Overview
Bariatric surgeries involve procedures that remove or bypass portions of the stomach to promote weight loss and reduce the production of ghrelin, an appetite-stimulating hormone. Introduced in the 1950s, surgical techniques have advanced, offering several options today.
GLP-1s (glucagon-like peptide-1 receptor agonists) are injectable medications initially used since 2005 for diabetes treatment. In 2014, the Food and Drug Administration (FDA) began approving them for weight loss, leading to increased popularity as a weight loss tool.
Types of Bariatric Surgery
The goal of these operations is to modify the stomach and intestines to treat obesity and related diseases. The operations may make the stomach smaller and also bypass a portion of the intestine. This results in less food intake and changes how the body absorbs food for energy resulting in decreased hunger and increased fullness. The common procedures endorsed by the American Society for Metabolic and Bariatric Surgery are listed and explained below. Each surgery has its own advantages and potential drawbacks.
Laparoscopic Sleeve Gastrectomy
The Laparoscopic Sleeve Gastrectomy, often called the “sleeve”, is performed by removing approximately 80% of the stomach. The new stomach holds less food and liquid helping reduce the amount of food (and calories) that are consumed. By removing the portion of the stomach that produces most of the “hunger hormone”, the surgery has an effect on the metabolism. It decreases hunger, increases fullness, and allows the body to reach and maintain a healthy weight as well as blood sugar control.
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Roux-en-Y Gastric Bypass
The Roux-en-Y Gastric Bypass, often called the “gastric bypass”, has now been performed for more than 50 years and the laparoscopic approach has been refined since 1993. It is one of the most common operations and is very effective in treating obesity and obesity related diseases. First, the stomach is divided into a smaller top portion (pouch) which is about the size of an egg. The small intestine is also divided and connected to the new stomach pouch to allow food to pass.
The gastric bypass works in several ways. Like many bariatric procedures, the newly created stomach pouch is smaller and able to hold less food, which means fewer calories are ingested. Additionally, the food does not come into contact with the first portion of the small bowel and this results in decreased absorption. Most importantly, the modification of the food course through the gastrointestinal tract has a profound effect to decrease hunger, increase fullness, and allow the body to reach and maintain a healthy weight. The impact on hormones and metabolic health often results in improvement of adult onset diabetes even before any weight loss occurs. The operation also helps patients with reflux (heart burn) and often the symptoms quickly improve. The average weight loss after gastric bypass is about 70% of excess body weight.
Adjustable Gastric Band
The Adjustable Gastric Band is a device made of silicone that is placed around the top part of the stomach to limit the amount of food a person can eat. It has been available in the United States since 2001. The impact on obesity related diseases and long-term weight loss is less than with other procedures. The feeling of fullness depends upon the size of the opening between the pouch and the rest of the stomach. The opening size can be adjusted with fluid injections through a port underneath the skin. Food goes through the stomach normally but is limited by the smaller opening of the band. Of all the available weight-loss surgeries, this one has the lowest average weight loss associated with it. The average weight loss with adjustable gastric banding is just 55 percent with adjustable gastric banding. One study published in American Family Physician indicates that 20 percent of adjustable gastric banding procedures fail completely.
However, it is an easily reversed procedure,so if something goes wrong, a surgeon can remove the band, and you can still consider other bariatric surgery types.
Biliopancreatic Diversion with Duodenal Switch (BPD-DS)
The Biliopancreatic Diversion with Duodenal Switch, abbreviated BPD-DS, begins with creation of a tube-shaped stomach pouch similar to the sleeve gastrectomy. The smaller stomach, shaped like a banana, allows patients to eat less food. The food stream bypasses roughly 75% of the small intestine, the most of any commonly performed approved procedures. This results in a significant decrease in the absorption of calories and nutrients. Patients must take vitamins and mineral supplements after surgery. Even more than gastric bypass and sleeve gastrectomy, the BPD-DS affects intestinal hormones in a manner that reduces hunger, increases fullness and improves blood sugar control. After a duodenal switch, it’s about 80%.
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Single Anastomosis Duodenal-Ileal Bypass with Sleeve Gastrectomy (SADI-S)
The Single Anastomosis Duodenal-Ileal Bypass with Sleeve Gastrectomy, referred to as the SADI-S is the most recent procedure to be endorsed by the American Society for Metabolic and Bariatric Surgery. A loop of intestine is measured several feet from its end and is then connected to the stomach. When the patient eats, food goes through the pouch and directly into the latter portion of the small intestine. The food then mixes with digestive juices from the first part of the small intestine. This allows enough absorption of vitamins and minerals to maintain healthy levels of nutrition.
Gastric bypass (Roux-en-Y)
The gastric bypass is also known as the “Roux-en-Y," which is a French term meaning “in the form of the letter Y.” With this procedure, your small intestine will end up in that form. First, surgeons create a small pouch at the top of your stomach, separating it from the lower portion with surgical staples. Then they divide your small intestine and bring the new segment up to connect to the stomach pouch. Food will now flow through the new, smaller stomach and lower segment of your small intestine, bypassing the rest. This restricts how much your stomach can hold and also how much nutrition your small intestine can absorb. Restricting the small intestine makes this method more effective than gastric restriction alone. Gastric bypass averages 71 percent of excess weight loss at three years.
Stomach Intestinal Pylorus Sparing Surgery (SIPS)
This newer procedure is a modified version of the original duodenal switch, intended to reduce complications. It also goes by the names Loop Duodenal Switch or SADI-s. Early results are still being studied, but so far it appears promising that this version may eventually replace the original duodenal switch. Like the original, it begins with a sleeve gastrectomy, then divides the first part of the small intestine just after the stomach (the duodenum). This time, the small intestine is reattached as a loop, which requires just one surgical connection (anastomosis) instead of two. It also means that less of the small intestine is bypassed, allowing for a little more absorption of nutrients.
Revisional Surgery
Revisional bariatric surgery is a procedure to reverse or modify an earlier weight loss surgery. It is typically done because the earlier procedure failed in some way. It may have produced disappointing outcomes or an undesirable effect. Studies indicate that between 5 to 8 percent of weight loss surgeries fail and require revisional procedures to correct or reverse them.
Some common reasons to have revisional surgery include:
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- Inadequate weight loss
- Weight gain
- Anastomotic stricture
- Stomal stricture
- Difficulty swallowing
- Frequent vomiting
- Ulcers
- Reflux
- Gastric dilation or enlargement
- Esophageal dilation
- Band erosion or slippage
- Gastro-gastric fistula
- Hernia
- Bowel obstruction
How the revisional procedure works will depend on the original bariatric surgery. In some cases, reversible surgery means converting one procedure to another. For instance, someone having problems with an adjustable band might have revisional surgery that includes gastric bypass. The goal of revisional surgery might be to modify the original procedure. For example, making the “sleeve” in a sleeve gastrectomy smaller.
Revisional surgery might completely reverse either a gastric bypass or an adjustable gastric band. Simply reversing the original surgery would likely lead to significant weight gain, though, so converting to a different type of bariatric procedure is often the goal.
GLP-1s: How They Work
GLP-1s are administered via weekly injections, with patients injecting themselves into the fatty tissue beneath the skin. A prescription is required to obtain these medications.
Eligibility Criteria: Bariatric Surgery
Bariatric surgery requirements begin with establishing a diagnosis of class III obesity. That means that you either:
- Have a BMI of 40 or higher. The Body Mass Index (BMI) is a way of estimating how much body fat you have based on your height-to-weight ratio. A score of 40 or higher is associated with a high risk of related diseases. It usually equates to about 100 lbs. overweight.
- Have a BMI of at least 35 and at least one related health problem. A BMI of 35 without a related health problem is considered class II obesity.
The criteria are slightly higher for adolescents. An adolescent may be a candidate if they have:
- BMI of at least 40 and an obesity-related medical condition.
- BMI of at least 35 and a severe obesity-related medical condition.
While BMI is easily measured, you may have to take some medical tests to diagnose your obesity-related health conditions.
Surgeons consider pre-existing conditions, such as gastroesophageal reflux disease and other comorbidities, to guide patients toward the most suitable operation. Before scheduling your bariatric surgery, your healthcare provider will want to ensure that you’re physically and mentally fit for the surgery. You’ll meet with a team of specialists who will counsel you about the risks and benefits while evaluating your physical and mental health.
You may need to pass medical screening tests to make sure the surgery is safe for you. If you use tobacco, drugs or excessive alcohol, you’ll be required to quit before qualifying for surgery. Your healthcare team can help you with this.
Your surgeon may also ask you to follow a pre-bariatric surgery diet for a few weeks to prepare for your operation. This is to reduce the fat inside your abdomen, where the operation will take place, making the operation safer and reducing the risk of complications. Your surgeon will give you specific guidelines to follow.
Weight Loss Effectiveness: Bariatric Surgery vs. GLP-1s
People who have bariatric surgery may lose 100 pounds, or 60% to 70% of their excess body weight. Studies show that people who lose weight after bariatric surgery tend to keep most or all of it off, and have much lower occurrences of obesity-related conditions such as type 2 diabetes or heart disease.
These injectables are not effective for everybody, and it is not yet well known why some people have success losing weight with GLP-1s and others do not. In the most successful cases, people can lose about 30 pounds, or as much as 20% of their body weight. However, the medications work only as long as patients continue to take them.
Recovery and Side Effects
Potential side effects after bariatric surgery tend to be from the surgery itself, including nausea from the anesthesia or pain at the incision site.
Some people taking GLP-1s experience nausea, fatigue, dizziness, and constipation.
Cost Considerations
The cost of bariatric surgery will depend on several factors, including the type of surgery and your insurance plan.
GLP-1s are typically not covered by insurance as a weight loss treatment. Brand-name medications, such as Ozempic, Wegovy, Zepbound, and Mounjaro, can cost $1,000 or more per month. Some GLP-1s are approved to treat type 2 diabetes.
The Importance of a Comprehensive Approach
Obesity is a complex condition to treat. Some people find that combining both treatments can enhance outcomes. A first step in any weight loss plan is to talk with your primary care provider.
All of the procedures discussed above are endorsed by the American Society for Metabolic and Bariatric Surgery and are excellent options to help you achieve healthy, long-term weight loss and improve medical conditions related to obesity. While all operations have risks, bariatric procedures performed at accredited centers are safe and have a low risk for complications.
Successful bariatric surgery requires a team-based approach including your surgeon, dietitian, psychologist, nurse case manager, and obesity medicine specialist who will focus on taking you through each step of the journey. Patients will do better if they continue to eat healthy, engage in physical activity, keep their appointments with obesity medicine providers, and take vitamins and mineral supplements as instructed. Your bariatric care team will provide you with lifelong support to succeed and maintain a permanent healthy lifestyle including changes to your diet and regular physical activity.
Common Myths About Bariatric Surgery
- That surgery is a last resort. Bariatric surgery is the most effective long-term treatment for class III obesity. When studied scientifically, diet and exercise - alone or in combination with medications - are much less effective over the long term.
- That surgery is the “easy way out.” Bariatric surgery can be thought of as a tool that allows a healthy diet and lifestyle to lead to sustained weight loss. Often, patients have made these changes before without long-term success. Surgery allows those changes to be effective.
What kind of postoperative care will I have after weight loss surgery?
During the first year after your surgery, your healthcare provider will see you regularly for follow-up visits and testing. They will take metabolic blood tests to monitor how your health is improving and screen for any nutritional deficiencies. After the first year, if you're in good health and have lost a lot of weight, you may want to discuss body contouring options with your healthcare provider. Body contouring can help remove excess skin folds and tighten loose tissues.
Making the Right Choice
Choosing the right weight loss surgery involves a collaborative decision between you and your doctor. Factors such as medical history, lifestyle, and risk aversion play a crucial role. There is no universally "better" surgery; the most suitable option depends on individual body type and weight loss goals. Researching available surgeries and discussing their potential impact with your weight loss surgery team is essential for informed decision-making.
Is Weight Loss Surgery Right for Me?
Again, that is a decision you will make with your doctor. There are qualifications you must meet before you can be a candidate for any bariatric surgery, including:
- A BMI of 40 or more
- A BMI of 35 to 39.9 with existing weight-related health problems, including hypertension, type 2 diabetes, or severe sleep apnea.
The surgeon may disqualify you based on other factors, too, like health conditions that make this kind of surgery unsafe for you.
The choice to have this surgery is not something you shouldn’t make lightly. There are potential risks that come with any surgical procedure, such as infection or blood clots. You must also be willing to make the long-term commitment necessary for bariatric surgery. There are significant dietary restrictions that you will have to follow for the rest of your life. You must also be willing to adhere to an exercise program, take dietary supplements, and keep follow up appointments.
However, bariatric surgery is a tool to help you be healthier if you are willing to stick with the program and follow the rules that come with it. Many benefits can come from bariatric surgery; people who undergo bariatric surgery tend to have lower blood pressures, healthier joints, and even reverse type two diabetes.