Gastric Sleeve vs. Gastric Bypass: Which Is Right for You?
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Medically reviewed by Jay N. Yepuri, MD, MS
Gastric sleeve and gastric bypass are the two most common types of surgical weight loss. Both surgeries share the goal of weight loss by reducing the amount of food consumed and how the body absorbs it. They also have similar safety records. However, there are some important differences between the two surgeries.
The best weight loss surgery option for you will depend on factors like your weight, medical history, expectations, and personal preferences.
In this article, learn about the differences between gastric sleeve and gastric bypass surgery and how to choose the right one for you.
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What Is Bariatric Surgery?
"Bariatric surgery" is another term for "weight loss surgery." If someone experiencing obesity has difficulty losing weight through lifestyle changes like diet and exercise, they may consider bariatric surgery.
There are various types of bariatric surgery intending to aid in weight loss. The two most common types of bariatric surgery are gastric sleeve and gastric bypass surgery.
Gastric Sleeve
Gastric sleeve surgery also called a laparoscopic sleeve gastrectomy, is the most common type of bariatric surgery.
During this procedure, approximately 80% of the stomach is surgically removed, including the area of the stomach that produces the most ghrelin, known as the hunger hormone. The stomach becomes much smaller and is shaped like a banana.
After the procedure, the stomach cannot hold as much food, and you experience less hunger. Overall, you will consume fewer calories and improve your metabolism, which can lead to weight loss and better blood sugar control.
Related:Gastric Sleeve Surgery: Overview
Gastric Bypass
Gastric bypass surgery, also called Roux-en-Y gastric bypass, has long been considered the gold standard of weight loss surgery.
During this procedure, the stomach is stapled, creating a small upper pouch and blocking off the lower portion of the stomach. Then, the middle section of the small intestine (called the jejunum) is connected to the small upper pouch.
By the end of the surgery, any consumed food or liquid bypasses the stomach. The result is fewer consumed calories due to the small stomach pouch, and fewer calories are absorbed because the first section of the small intestine is also bypassed. The person will feel less hungry and more full, which aids in weight loss and metabolic health.
Gastric sleeve and gastric bypass are not the only types of bariatric surgery. Other types of bariatric surgery, endorsed by the American Society for Metabolic and Bariatric Surgery, include:
Biliopancreatic diversion with duodenal switch
Single anastomosis duodeno-ileal bypass
Related:Gastric Bypass Surgery: Overview
Gastric Sleeve and Gastric Bypass Differences
There are some important differences between gastric sleeve and gastric bypass surgeries.
Gastric sleeve surgery is a more straightforward procedure, whereas gastric bypass surgery requires multiple steps to connect the intestine to the upper stomach pouch.
Gastric bypass is associated with more possible side effects than gastric sleeve. However, gastric bypass may also lead to longer-lasting weight loss and blood sugar control.
Read more about the differences between gastric sleeve and gastric bypass procedures below.
Requirements
Requirements for bariatric surgery are related to body mass index (BMI). You can calculate BMI by dividing weight (in pounds) by height (in inches squared) and multiplying by 703.
Candidates for bariatric surgery include people who have:
A BMI of 40 or greater
A BMI of 35 or greater in addition to an obesity-related health condition like type 2 diabetes, sleep apnea, or heart disease
A BMI of 30 or greater, in addition, to type 2 diabetes that is not well controlled with lifestyle changes and medical treatments
These requirements are not specified as differing for gastric sleeve vs. gastric bypass.
However, gastric bypass is usually recommended for people with a higher BMI (greater than 45) because it can lead to faster and more significant weight loss. It is also a more complex surgery with more possible complications.
Related:What Is Body Mass Index (BMI)?
Success Rate
Bariatric surgeries are usually very successful. About 90% of people who have bariatric surgery lose 50% of excess body weight and keep it off long term.
There are some differences, however, in the rate and amount of weight loss after gastric sleeve vs. gastric bypass surgery.
Generally, bariatric surgeons will tell you that gastric bypass surgery may lead to faster and more significant weight loss in the long term.
One seminal (significant) study called the SLEEVEPASS randomized clinical trial compared the results of gastric sleeve and gastric bypass patients five years after surgery. The researchers found that those who had gastric sleeve surgery lost 49% of excess weight, compared to 57% of excess weight among the gastric bypass group.
Recovery
Both gastric sleeve and gastric bypass can be performed with a minimally invasive technique in which small incisions are made in the abdomen. This advancement in bariatric surgery has helped improve recovery times.
The two surgical procedures involve similar lengths of hospital stays (one to three days) and overall recovery times (four to six 6 weeks).
Ultimately, recovery time will depend on your unique situation, including your presurgical weight, mobility, and any co-occurring conditions.
Complications
Possible complications differ between gastric sleeve and gastric bypass procedures. Both gastric sleeve and gastric bypass procedures are considered safe, and the risk of death is extremely low. However, like any major surgery, they both have possible side effects and complications.
Gastric sleeve is a comparatively more straightforward procedure and associated with fewer complications. However, it is more likely to cause severe gastroesophageal reflux disorder (GERD) than gastric bypass.
Gastric bypass has many possible complications as it is a more complex procedure. This includes a greater risk of nutrient deficiencies (including calcium, B12, iron, and folate) because the stomach and small intestine, which are bypassed are essential in nutrient absorption.
Other side effects unique to gastric bypass include stomach ulcers, small bowel obstruction, and dumping syndrome (a feeling of sickness after eating due to undigested food passing directly into the intestines).
Dietary Changes
Both gastric sleeve and gastric bypass surgeries require changes in your diet post-surgery due to the smaller size of your stomach to help maintain long-term weight loss.
Dietary changes after gastric sleeve and gastric bypass surgery include:
A phased return from liquid to soft foods to a solid diet after surgery
Consuming smaller meals long term
Eating slowly and chewing your food thoroughly
Taking certain vitamin and mineral supplements or B12 injections
Paying attention to when you feel full and stop eating
Sipping fluids rather than gulping
Avoiding carbonated drinks or foods that are difficult to digest (like white bread)
Consulting with a dietitian after surgery
One way that gastric sleeve and gastric bypass differ is in the amount of food that your dietitian recommends you consume.
The size of your stomach after gastric sleeve surgery is about 2 to 5 ounces (oz), compared to 1 oz after gastric bypass (consider that an average stomach volume is about 33 oz). People with gastric bypass must consume even smaller amounts of food and liquid.
Comparing Gastric Sleeve and Gastric Bypass
Gastric sleeve and gastric bypass share the common goals of weight loss, metabolic health, and improved quality of life. Despite many similarities, there are some key differences between the two surgeries. It may help you to consider the pros and cons of each procedure.
Gastric Sleeve Pros and Cons
Generally, gastric sleeve surgery is less complex and fewer side effects. However, while it is still very effective at weight loss, it doesn't lead to as swift or significant a weight loss as gastric bypass.
Pros of gastric sleeve surgery:
Simpler surgery
Appropriate for some people with high-risk medical conditions
Effective for weight loss
Can be transformed into a gastric bypass if recommended in the future
Cons of gastric sleeve surgery:
Can cause or significantly worsen GERD
Not reversible
Less impact on metabolism
Related:Gastric Sleeve Surgery Complications and Risks
Gastric Bypass Pros and Cons
Compared to gastric sleeve surgery, gastric bypass is more complex since it requires multiple steps to connect the small intestine to the new stomach pouch. This surgery can lead to faster and more significant weight loss but can also have more side effects.
Pros of gastric bypass surgery:
Standardized surgical technique
Faster and more significant weight loss
Can help treat obesity-related conditions like type 2 diabetes
Cons of gastric bypass surgery:
More complex surgery
Can lead to dumping syndrome
Risk of vitamin and mineral deficiencies, requiring lifelong supplementation
Risk for bowel obstruction
Risk for ulcers, particularly if using nonsteroidal anti-inflammatory drugs (NSAIDs) or tobacco
Related:Malnutrition After Gastric Bypass Surgery
Which One Is Right for You?
Talk to a healthcare provider or bariatric surgeon about which surgery is right for you.
You might choose a gastric sleeve surgery if you desire a more straightforward surgery with less chance of complications or if you have a high-risk health condition that contraindicates (gives a reason to not get) a gastric bypass procedure.
You might choose a gastric bypass surgery if you have more severe obesity and desire faster weight loss or have an obesity-related condition like type 2 diabetes that you are also seeking to treat.
Summary
Gastric sleeve and gastric bypass are the two most common weight loss surgeries. Gastric sleeve is a comparatively more straightforward procedure that involves removing 80% of the stomach. Gastric bypass is a multistep surgery in which the stomach is bypassed, so food travels directly to the small intestine.
The right type of surgery for you will depend on individual factors like BMI, co-occurring health conditions, expectations, and goals.
Frequently Asked Questions
Is surgery a permanent solution to weight loss?
Bariatric surgery, when combined with a commitment to lifestyle and dietary changes, can lead to long-term weight loss. According to the American Society for Metabolic and Bariatric Surgery, about 90% of people who have bariatric surgery lose 50% of excess body weight and keep it off long term.
Are bariatric surgeries painful?
Bariatric surgeries are safe procedures that can be performed laparoscopically (through small incisions), but like any major surgery, they can result in postoperative pain.
Do you lose weight faster with gastric bypass or gastric sleeve surgery?
People tend to lose weight faster with gastric bypass vs. gastric sleeve surgery.
