What Is Gastric Sleeve Weight Loss Surgery?

Written by Kris Martins, Kathryn Whitbourne
Medically Reviewed by Melinda Ratini, MS, DO on September 08, 2025
10 min read

Also called sleeve gastrectomy, this is a weight loss surgery that removes a large part of your stomach and leaves a small "sleeve” behind so you become less hungry and eat fewer calories. 

The gastric sleeve procedure is also known as vertical sleeve gastrectomy (VSG). It works for weight loss by removing about 80% of your stomach, leaving behind a gastric sleeve stomach about the size of a banana. This leaves less space for food, so you feel full faster. It also lowers the amount of hunger hormones your stomach can pump out. This helps keep you from having as much of an appetite or craving for food.

Gastric sleeve weight loss can be a helpful choice if you have serious obesity and are looking to lose weight effectively. VSG surgery can also help treat obesity-related conditions such as high blood pressure, high cholesterol, and diabetes.

While both of these are types of weight loss surgeries that can help you lose 59%-70% of extra weight within two years, they do have some key differences.

The surgery. In gastric bypass, the surgeon divides your stomach into a small top part and a larger bottom part. They then connect the smaller stomach pouch straight to the small intestine, skipping the larger part of your stomach entirely. In gastric sleeve surgery, a part of your stomach is actually removed, which makes it a simpler procedure.

Weight loss results. People usually see faster weight loss in the months after gastric bypass compared to gastric sleeve surgery. You can often lose more weight overall long term with gastric bypass, but you're more likely to have low levels of vitamins and minerals later.

Ideal patient type. Gastric sleeve surgery is best for people who have a body mass index (BMI) of at least 40. That means you're 100 pounds or more over your ideal weight. Some people are too heavy for gastric bypass surgery, so VSG may be a good alternative.

Pros and cons of gastric sleeve 

Every weight loss surgery has its benefits and disadvantages, but surgeons often note that the benefits of gastric sleeve outweigh the downsides.

Pros of gastric sleeve

  • It's a simple and safe procedure.
  • It has a shorter surgery time.
  • Recovery is quick.
  • It effectively helps you lose weight.
  • It helps lower the chance of other diseases such as type 2 diabetes, high blood pressure, and certain cancers.
  • You can get it even if you have high-risk medical conditions.
  • It can be a good first step for tackling serious obesity.
  • It can serve as a bridge to other weight loss surgeries such as gastric bypass or single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S). 
  • It doesn't come with the potential problems of small intestine surgery.
  • It can raise your life expectancy.

Cons of gastric sleeve

  • It's permanent.
  • It can cause or worsen acid reflux or heartburn.
  • It doesn't affect your metabolism as much as gastric bypass.

Your surgeon will give you anesthesia and make a few small cuts in your belly. In one, they'll insert a laparoscope — an instrument with a tiny camera that sends pictures to a monitor to guide them. They'll then insert other medical instruments through the other cuts and remove about three quarters of your stomach. Finally, they'll reattach the rest of your stomach with staples to form the "sleeve" or tube-shaped stomach. 

The laparoscopic VSG is often performed robotically. It may make recovery even quicker. Alternately, your doctor may decide to do open surgery, depending on any medical conditions you may have.

How long does gastric sleeve surgery take?

The surgery typically takes about 60-90 minutes. You might be in the hospital for about two or three days. During that time, your surgeon can help you with any immediate post-surgery pain or side effects.

While you're in the hospital directly after surgery, your care team will watch you for:

  • Pain management  
  • Ability to drink liquids  
  • Mobility  
  • Early signs of any issues, such as bleeding or leakage

Once you get home, what you eat and how active you are will play a big role in your recovery. Keep in mind that it can take a full month to feel like yourself again or go fully back to work.

Meals. You'll move from liquids to solids over time, usually in about a month. You can eat more solid foods as your stomach heals. As it does and as your body gets used to fewer calories, you may feel more fatigued or tired. That's normal. Your stomach can be sensitive for three to six months after surgery and sometimes longer.

Exercise. You may want to take it easy as you heal. At first, light walking is OK. About four to six weeks later, you can do harder exercises.

Checkups. Part of recovery will be visiting your care team often for many months after surgery. They'll check your progress in weight loss, any other health conditions, and potential side effects of the surgery. They may also order lab tests, blood tests, and other exams yearly to suggest supplements and other lifestyle changes.

"This is not just a quick procedure," says J.R. Salameh, bariatric surgeon and medical director of the VHC Health Bariatric and Metabolic Health Center in Arlington, VA. "You're signing up for a whole lifestyle change, and you really want that whole team…to help you along the way."

After surgery, your surgeon may suggest that you join a holistic bariatric program — some are certified by the American College of Surgeons — that includes a range of professionals to support you through this big lifestyle change. In addition to your surgeon, these programs can also include:

  • Registered dietitians
  • Psychologists
  • Bariatric medicine doctors
  • Bariatric endoscopists
  • Exercise specialists

Beginning the first day after surgery, you'll drink sugar-free, noncarbonated liquids and protein drinks for about one week. You'll move onto pureed food for three weeks, then soft foods, and eventually back to solids as your stomach heals. Your recovery meal plan will pack a lot of protein to help you heal and keep you from losing hair and lean muscle mass.

After recovery, your eating habits will have to change permanently, now that your stomach is smaller. Here are some pointers to help you with it:

  • Eat proteins first, then produce, and finish with starches. Use fats to keep food from getting too dry, which can make them hard to eat.
  • Chew everything thoroughly before you swallow it.
  • Don't drink while you eat, as this might cause your new stomach to overfill.
  • Drink liquids a half hour after finishing a meal.
  • Avoid high-calorie sodas and snacking.
  • Stop eating when you first start to feel full, which can feel like nausea or chest pressure.
  • Take vitamin and mineral supplements, such as calcium and vitamin B12, every day. You'll need to do this for the rest of your life to make sure your body has enough nutrients when you're eating less.

After two or three months, you can move on to everyday meals. But remember, you will not be able to eat as much as you used to.

People generally lose 60% of their extra weight over 12-18 months. So, if you are 100 pounds overweight, you'll lose about 60 pounds, though some people lose more and others less. Of course, exercising and eating right add to your weight loss. 

While there aren't consistent study results that show you'll lose more or less weight depending on your gender or ethnicity, other things can affect your weight loss.

Age. Younger people lose more weight and for longer periods of time, whereas older people may not lose as much weight and might gain some back.

Starting BMI. If you have a higher starting BMI, you may end up with a higher BMI after you lose weight than people who started with a lower one. This is true even if you've lost more total weight than them.

Gastric sleeve before and after

Everyone's body is different, but on average, patients lose most of their extra weight over the first year.

"[Weight loss] is going to be fairly rapid the first six months," Salameh says. "It'll slow down after six months, but it will go on after a year."

You'll likely lose weight on the parts of your body where you carry it the most. As with any major weight loss, you'll probably see some loose skin as a result. When your skin stretches from weight gain, it loses its elasticity. After you lose weight, it won't shrink completely back to where it was before. How loose your skin will be can depend on your age, how much weight you lost, and where on your body you lost most of it.

Gastric sleeve surgery normally has a lower rate of issues than other common surgeries, with issues happening in less than 1% of surgeries. Plus, because it's minimally invasive, it's less painful, and heals quickly. Still, as with any surgery, there are short- and long-term cons.

In the short term, downsides and issues include:

  • Bleeding
  • A leak along the staple line (in rare cases)
  • Nausea, vomiting, or constipation right after surgery
  • Infection
  • A bad reaction to anesthesia
  • Blood clots
  • Lung or breathing problems

In the long term, the biggest potential problem is you may get acid reflux. "That may be mild, but (you'll) take something as needed. Or it can be significant to a point where it would require daily medication, or rarely, but occasionally, another surgery," Salameh says.

Other long-term cons include:

  • Intestinal blockage, which can cause nausea, vomiting, and trouble eating
  • Hernias
  • Low blood sugar, known as hypoglycemia
  • Gallstones, which can cause pain and may need another surgery
  • Some weight gain after a couple of years

Certain foods may not agree with you now. You may also have nutrition problems after surgery, which is why you'll have to take vitamins and supplements for life. Your doctor will let you know exactly what you need.

"With bariatric surgery, with the weight loss that's sustained long term, we see an improvement not only in overall health, but life expectancy and quality of life," Salameh says. "All of these certainly outweigh any of those risks."

  • Gastric sleeve surgery, also known as sleeve gastrectomy, is the most common weight-loss surgery in the U.S. It has a high success rate and relatively few problems. 
  • The procedure is ideal for people who need to lose a large amount of weight. 
  • The surgery is simple and quick: Surgeons remove about 80% of your stomach, leaving only a small "sleeve" behind so you stay less hungry and eat fewer calories. 
  • Recovery takes about a month, and most people lose 60%-70% of their extra weight within one or two years as they work with their care team to make lifestyle changes to support a smaller stomach.

How fast do you lose weight after gastric sleeve surgery?

Weight loss varies depending on the person, but the following results are typically what you can expect. For the first two weeks, you'll lose about a pound a day. Within a few months, you should see 35%-45% of extra weight loss. By one year, you'll lose 60%-70% of extra weight, with most people hitting their lowest weight one to two years after surgery.

Is gastric sleeve surgery safe?

Gastric sleeve surgery is the most common weight loss surgery in the U.S. It typically has a lower rate of issues than other common procedures. Problems happen in less than 1% of surgeries.

Is there anything you can never eat again after bariatric surgery?

There aren't any foods that you can't ever eat again after gastric sleeve. Your stomach can handle it all even if it is smaller. But you'll want to stay away from any foods that don't align with healthy eating habits and lifestyle changes your care team suggests. Make sure you chew your food well and eat smaller meals.

Who should not have gastric sleeve surgery? 

You may not be able to get this surgery if:

  • You don't have a BMI of 40 or higher
  • You ​have blood-clotting disorders
  • You have serious heart disease that keeps you from getting anesthesia safely
  • You have other conditions that make anesthesia risky
  • You already deal with acid reflux or take heartburn medication
  • You have a very high BMI or 200 pounds or more to lose

Can gastric sleeve surgery fail?

You may not lose enough weight, or you may gain weight back after gastric sleeve surgery. There can be many reasons why this happens, but most of the time it's because people don't stick with the suggested post-surgery lifestyle changes.

"Anybody who loses less than 50% of the excess weight they carry, we typically consider that a 'failure' or not having done as well as we hoped they would," Salameh says. He reports that this happens with 20%-30% of his patients.

The main ways to fix this are:

  • Small and frequent meals, healthy food, and exercise
  • Weight loss medication in the short or long term
  • Revision bariatric surgery, with the most common being single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S)