Bariatric surgery is surgery to help you lose weight. This type of surgery is only used for people who are very overweight and have not been able to lose weight with diet and exercise.
This surgery makes the stomach smaller. Some types of surgery also change the connection between your stomach and intestines.
Having weight-loss surgery is a big step. After surgery, you'll need to make new, lifelong changes in how you eat and drink.
What are the types of weight-loss surgery?
Depending on whether your weight-loss surgery is to make your stomach smaller or to change the path of your intestine, your doctor will perform one of these procedures:
- Adjustable gastric banding.
The doctor wraps a band around the upper part of the stomach to make the stomach smaller.
- Gastric sleeve.
The doctor removes more than half of your stomach, leaving a thin vertical sleeve, or tube.
- Gastric bypass.
The doctor uses a small part of your stomach to create a smaller stomach. This is connected to the middle part of the small intestine. Food skips (bypasses) the rest of the stomach and part of the small intestine. This surgery is called a Roux-en-Y (say "roo-en-why") gastric bypass.
You may stay in the hospital for one or more days after the surgery. How long you stay depends on the type of surgery you had.
Most people need 2 to 4 weeks before they are ready to get back to their usual routine.
Your doctor will give you specific instructions about what to eat after the surgery. You'll start with only small amounts of soft foods and liquids. Bit by bit, you will be able to eat more solid foods. Your doctor may advise you to work with a dietitian. This way you'll be sure to get enough protein, vitamins, and minerals while you are losing weight. Even with a healthy diet, you may need to take vitamin and mineral supplements.
After surgery, you will not be able to eat very much at one time. You will get full quickly. Try not to eat too much at one time or eat foods that are high in fat or sugar. If you do, you may vomit, get stomach pain, or have diarrhea.
You probably will lose weight very quickly in the first few months after surgery. As time goes on, your weight loss will slow down. You will have regular doctor visits to check how you are doing.
It is common to have many emotions after this surgery. You may feel happy or excited as you begin to lose weight. But you may also feel overwhelmed or frustrated by the changes that you have to make in your diet, activity, and lifestyle. Talk with your doctor if you have concerns or questions.
Think of bariatric surgery as a tool to help you lose weight. It isn't an instant fix. You will still need to eat a healthy diet and get regular exercise. This will help you reach your weight goal and avoid regaining the weight you lose.
You have this type of surgery to help you lose weight. It may be considered if your body mass index (BMI) is at least 40, or if it's at least 35 and you have other weight-related health problems. If your BMI is 35 or higher, surgery may be done if you have tried for at least 6 months to lose weight.
Depending on the type of surgery, most people lose at least a third of their extra weight after surgery. Some people lose almost all of their extra weight. Weight loss varies with the type of surgery. It also depends on how closely people follow their doctor's advice for lifestyle changes, checkups, and counseling.
Research shows that people who have gastric bypass surgery lose more total weight than those who have gastric sleeve or gastric banding surgery. But those who have gastric bypass surgery have more complications right after surgery.1
Here are some risks common to all surgeries for weight loss:
- You could get an infection in the incision.
- You could get a blood clot in your legs (deep vein thrombosis, or DVT) or lung (pulmonary embolism).
- You may not get enough of certain vitamins and minerals. This can lead to problems such as anemia and osteoporosis.
- Some people get gallstones.
- Some people get kidney stones.
- You may gain the weight back a few years after surgery if you don't follow your eating and lifestyle plan.
Risks of each type of surgery
Talk to your doctor to understand all of your risks. Here are some of the most common or serious risks for each type of weight-loss surgery:
- Adjustable gastric banding.
After this surgery, you are more likely to need another surgery to fix problems than you would after gastric bypass. For example, some people need a second surgery because they aren't happy with having the band. Or the band can slip. Or it can work its way from the outside of the stomach to the inside. This is called an erosion.
- Gastric bypass and gastric sleeve surgeries.
These can cause a leak from the stomach into the belly area. The leak can cause an infection called peritonitis.
- Gastric bypass.
With this surgery, the connection between the stomach and the small intestine can get narrow. This can cause nausea and vomiting after you eat.
- Arterburn D, et al. (2018). Comparative effectiveness and safety of bariatric procedures for weight loss: A PCORnet cohort study. Annals of Internal Medicine. DOI: 10.7326/M17-2786. Accessed August 21, 2020.
Current as of: March 17, 2021
Author: Healthwise Staff
Kathleen Romito MD - Family Medicine
Martin J. Gabica MD - Family Medicine
David E. Arterburn MD, MPH - Internal Medicine