Gastric sleeve vs. gastric bypass: Pros and cons

As you start researching weight loss surgeries, you’re likely to see the names of two procedures over and over again. Gastric sleeve (vertical sleeve gastrectomy) and gastric bypass (Roux-en-Y) are the most common types of bariatric surgery for weight loss. In fact, 80% of weight loss surgeries in the United States are one of these two procedures.
The best weight loss surgery for you will depend on factors such as how much weight you have to lose and how your extra weight is affecting your overall health. You may also be able to get to a healthier size through a medical weight management program that offers personalized support from health care experts.
If surgery is an option for you, your bariatrician (a doctor that specializes in treating obesity) will likely recommend a specific surgery for you. Keep reading to find out the differences and similarities of these weight loss procedures, and the pros and cons of each.
Gastric sleeve and gastric bypass change your body in different ways
Gastric sleeve and gastric bypass procedures are similar in that each make your stomach smaller and affect how much “hunger” hormone (ghrelin) your body produces. But there are some key differences in what happens during surgery.
Gastric sleeve is simpler than gastric bypass
During gastric sleeve surgery, your doctor removes about 80% of your stomach, leaving a pouch that’s about the size and shape of a banana. The part of the stomach that makes most of the “hunger hormone” is removed during the procedure, so you’ll feel less hungry. But there are no changes to your intestines, so food will continue to travel through your digestive system as it does now.
Gastric bypass changes your metabolism
Gastric bypass is a procedure that changes both your stomach and your digestive tract. To make your stomach smaller, the doctor divides your stomach into two parts. They use the top part to create an egg-sized pouch for your food. The rest of your stomach is bypassed and will no longer be used to store or digest food. This surgery also changes the layout of your intestines and where food enters your stomach.
Gastric bypass works because it affects hunger and also encourages changes in your hormones and metabolism. These changes can help you move beyond weight loss plateaus, so you’re able to successfully lose weight with lifestyle changes.
So which is better, gastric sleeve or gastric bypass? It depends
Both gastric bypass and gastric sleeve are relatively safe and can help people lose a lot of weight and improve their health. In fact, studies show that weight loss surgery can greatly improve overall health and reduce the chance of premature death by 30-50%. Still, gastric sleeve and gastric bypass surgeries have unique pros and cons that you and your doctor will talk through together to decide which surgery is the best option for you.
Pros and cons of gastric sleeve surgery
Gastric sleeve surgery makes your stomach smaller but allows your digestive system to work normally. This results in certain upsides and downsides to gastric sleeve surgery.
Pros of gastric sleeve surgery

Generally considered the safest form of weight loss surgery: This is mostly because gastric sleeve surgery is simpler than gastric bypass, making it even less likely that there will be problems during surgery or as you recover.
Less likely to cause digestion problems: This surgery doesn’t speed up digestion or affect your ability to absorb vitamins and nutrients from your food. This means that you’re less likely to have complications like malnutrition, diarrhea and nausea.
Effective weight loss: People often lose 60-70% of their excess weight after gastric sleeve surgery, and most are able to keep it off long-term.
May reduce symptoms of weight-related medical conditions: Weight loss surgery can reduce symptoms of conditions like type 2 diabetes, heart disease, stroke, obstructive sleep apnea, liver disease, gallbladder disease, some cancers, cataracts, infertility and polycystic ovary syndrome.
Possible to change into a gastric bypass: If you don’t experience health improvements with a gastric sleeve, it may be possible to change it to a gastric bypass.

Cons of gastric sleeve surgery

May not lose weight as quickly: It can take a little longer to get to your target weight after gastric sleeve surgery. But there’s no significant difference in long-term weight loss between the procedures.
Can cause acid reflux or make it worse: This procedure can cause acid reflux because it increases the pressure on the lower esophageal sphincter, the ring of muscle that opens and closes the bottom of the esophagus.
Chance of long-term complications: While most people don’t have long-term complications, they are still possible. For gastric sleeves, one long-term risk includes gastroesophageal reflux disorder (GERD).

Pros and cons of gastric bypass surgery
Gastric bypass surgery changes both the size of your stomach and how your body processes food. With gastric bypass you may lose weight more quickly, but you’re more likely to have long-term digestion problems.
Pros of gastric bypass

Lose weight more quickly: Since the surgery reduces the amount of nutrients you get from your food, you can lose weight more quickly.
Lose more weight: People often lose 70-80% of their excess weight within a year.
May help treat weight-related conditions: With gastric bypass, you may see improvements in weight-related conditions like type 2 diabetes, sleep apnea and hypertension.
Less likely to make acid reflux worse: Gastric bypass may be an option if you’re unable to have a gastric sleeve procedure because you have acid reflux. Still, about 20% of people have chronic reflux after this surgery.
Relatively safe: The chance of a major complication is about 4% according to the American Society for Metabolic and Bariatric Surgery (ASMBS).

Cons of gastric bypass

Possibility of dumping syndrome: People with gastric bypass are more likely to have dumping syndrome, a condition which leads to diarrhea, flushing, lightheadedness, nausea or vomiting.
Chance of vitamin and mineral deficiencies: If you’re not able to get nutrients from your food, you may need lifelong supplements.
More complex surgery: While the risks are still low, there’s a higher chance of surgical complications, including leaks and infections.
Chance of long-term complications: While complications aren’t common, they’re possible. They include increased sensitivity to alcohol, problems with nutrition, stomach ulcers, stomach perforation and bowel blockage.

Why your doctor may recommend gastric bypass or gastric sleeve surgery
Before getting weight loss surgery, you need to meet certain criteria. Eligibility for gastric sleeve or gastric bypass surgery is mostly based on your body mass index (BMI), which is calculated from your height and weight. If you have weight-related health conditions, you may be eligible for either surgery at a lower BMI.
If you meet the criteria for surgery, there may still be steps you need to take when preparing for bariatric surgery like making diet changes, increasing your movement and activity levels, and making other lifestyle changes.
Surgical criteria for gastric sleeve vs. gastric bypass

Health characteristic
Gastric sleeve
Gastric bypass

BMI of 40 or higher
Yes
Yes

BMI between 35-40, with at least one obesity-related medical condition
Yes
Yes

Metabolic syndrome*
No
Yes

Obesity that’s affecting your mobility and quality of life
No
Yes

*Metabolic syndrome is a condition that increases your chance of heart disease, diabetes and stroke. It’s possible you have metabolic syndrome if you have three or more of the following: high blood pressure, high blood sugar, too much fat around the waist, high triglyceride levels and low HDL levels.
Weight loss surgery cost: Gastric bypass usually costs more
The cost of weight loss surgery depends on the type of surgery you get, where you get it and your insurance coverage. However, gastric sleeve surgery tends to cost about 25% less than gastric bypass.
Gastric bypass and gastric sleeve surgeries are usually covered by insurance
Many, but not all, health insurance plans cover some of the costs of at least one type of bariatric surgery, provided you meet certain qualifications. Medicare and Medicaid also cover weight loss surgeries. Some plans also cover other types of weight loss procedures.

If you’re considering weight loss surgery, we can help
If you’re wondering if weight loss surgery could be a step towards better health, make an appointment with Park Nicollet Bariatric Surgery and Weight Center.
Our center offers a range of medical and surgical options, allowing us to create a personalized treatment plan for you, based on your needs and preferences. We’ll discuss the pros and cons of different types of treatments and weight loss surgeries, and help you decide what makes sense for you – whether that’s medical weight management or surgery.
No matter what’s next in your weight loss journey, we’ll get you on the best path and be there for you every step of the way.