Weight Loss Surgery: What It Is and What to Expect
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor provides Weight Loss Surgery?
A bariatric surgeon, a surgeon who treats heavy weight, performs the surgery. Before surgery, you also meet other health care professionals. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Weight-loss surgery is a group of operations that change your digestive system to help you lose weight. Some types make your stomach smaller, so you feel full sooner. Other types change the small intestine, so the body can absorb fewer calories. In the United States, three types are done most often.
- Gastric sleeve: the surgeon removes about 80 percent of the stomach.
- Gastric bypass: a small stomach pouch is attached to the middle part of the small intestine.
- Adjustable gastric band: a band around the top of the stomach makes a small pouch with an adjustable opening.
Why a doctor might recommend it
It may be an option for an adult with obesity. This is when eating plans, exercise, or medicines have not helped you lose weight, or the weight keeps coming back.
BMI, or body mass index, measures body fat from your weight and height. With a BMI of 35 or higher, obesity can be hard to treat with diet and exercise alone, so doctors may recommend surgery. With a BMI of 30 to 35 and type 2 diabetes that is hard to control, surgery may be considered.
How to prepare
Before surgery, you will meet these health professionals.
- The internist, a doctor for adult health, asks about your medical history, does a physical exam, and orders blood tests.
- The dietitian explains what and how much you can eat and drink after surgery.
- The psychiatrist or psychologist may check if you are ready for the challenges of surgery.
If you smoke, it may help to stop at least 6 weeks before surgery.
What happens during it
The surgery is mostly done with small cuts under general anesthesia, which means you are asleep. This kind of surgery has fewer risks than open surgery and may cause less pain and scarring. Some people may need open surgery. It uses one large cut in the belly.
Recovery
After surgery, you will need to rest and recover. Walking and moving around the house may help you recover more quickly.
After surgery, you will probably start with a liquid diet. Over several weeks, you will move to a soft diet with foods such as cottage cheese, yogurt, or soup. Later you will eat solid foods again. You will need the vitamin and mineral supplements that your health care professional prescribes.
Call 911 or go to the emergency room if you have trouble breathing, chest pain or discomfort lasting two minutes or more, fainting, coughing up or vomiting blood, or bleeding that will not stop.
Risks and side effects
Side effects may include blood clots in the legs that can move to the lungs or heart. Leaking can happen where sections of the stomach are joined. Rarely, surgery-related problems can lead to death.
Not getting enough nutrients can cause health problems, such as anemia (too few red blood cells) and osteoporosis (weak, brittle bones). A gastric band can slip out of place or wear into the stomach wall and need to be removed.
Who performs it
A bariatric surgeon performs the surgery.
Common questions
Can weight-loss surgery be reversed?
A gastric sleeve cannot be reversed, because part of the stomach is permanently removed. A gastric bypass is difficult to reverse, although a surgeon may do it if needed.
Will I keep all the weight off?
Not always, because no method, including surgery, is sure to keep weight off. On average, many people lose 15 to 30 percent of their starting weight, depending on the type of surgery. Over time, some people regain a portion of the weight they lost.
How does a direct primary care or concierge doctor fit in?
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
Sources
- National Institute of Diabetes and Digestive and Kidney Diseases - Types of Weight-loss Surgery
- National Institute of Diabetes and Digestive and Kidney Diseases - Weight-loss Surgery Side Effects
- National Institute of Diabetes and Digestive and Kidney Diseases - Definition and Facts of Weight-loss Surgery
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
