Understanding gastric sleeve surgery: A complete guide

Key Points

• Gastric sleeve surgery is a type of bariatric procedure where surgeons cut away a large portion of the stomach to reduce hunger and help people with obesity achieve rapid weight loss.
• Studies show that most patients retain their weight loss even 10 years after surgery.
• Most patients experience improved sleep, blood pressure, and blood sugar levels within months.
• Sustaining weight loss results in the long term is only possible with diet and lifestyle changes.

Managing severe obesity can feel like an uphill battle. Despite trying various diets, exercise programs, and lifestyle changes, many people find that losing weight and keeping it off is extremely difficult. Gastric sleeve surgery is a type of bariatric surgery that has become popular to help manage severe obesity and weight-related health issues.

"For people with obesity, losing weight has nothing to do with 'willpower'," says Gia Eapen, MD. "Science shows that obesity is complex. It has underlying hormonal imbalances that actively work against weight loss, making traditional methods less effective over time. If you're living with severe obesity or supporting a loved one, understanding treatment options helps guide important conversations with healthcare providers."

This guide explains gastric sleeve surgery in clear terms - from how it works and what research shows to what you can expect afterward - to help you better understand this treatment option.

What is gastric sleeve surgery?

Gastric sleeve surgery, also called sleeve gastrectomy, is a type of weight loss surgery that works by changing both the size of the stomach and certain hormonal signals in the body. During the procedure, a surgeon removes about 80% of the stomach, creating a smaller, tube-shaped stomach roughly the size of a banana.

This change affects the body in two main ways. First, the smaller stomach naturally limits portion sizes, helping people feel satisfied with less food. Second, and perhaps more importantly, the surgery reduces the production of ghrelin, often called the "hunger hormone." This hormonal change often helps people feel less hungry throughout the day, making it easier to maintain healthier eating patterns.

The gastric sleeve is considered a relatively straightforward approach compared to some other types of weight loss surgery because it doesn't involve rerouting the intestines or placing artificial devices in the body.

However, like any surgical procedure, it requires careful consideration and discussion with healthcare providers to determine if it's appropriate for an individual's specific situation.

Who is eligible for gastric sleeve surgery?

Most people who explore gastric sleeve surgery have tried many ways to lose weight over the years, sometimes decades.

Healthcare providers typically consider gastric sleeve surgery for adults with severe obesity, which means having a Body Mass Index (BMI) of 40 or higher. They may also consider it for people with a BMI between 35 and 40 who have obesity-related health conditions like type 2 diabetes, high blood pressure, or severe sleep apnea.

Says Eapen, MD, "The decision to pursue surgery isn't just about numbers on a scale. Healthcare teams look at the overall picture of a person's health, including their medical history, current health status, and ability to follow post-surgery guidelines. They also consider how obesity affects someone's daily life, from mobility issues to impacts on work and social activities."

How does gastric sleeve surgery work for weight loss?

Gastric sleeve surgery helps with weight loss in two key ways. When the surgeon makes your stomach smaller, they also remove cells that produce hunger hormones, like ghrelin. These changes work together to help you lose weight.

Let's explore how each change affects your body:

• Making the stomach physically smaller helps control portion sizes. A smaller stomach fills up more quickly, sending "fullness" signals to the brain sooner during meals. Think of it like replacing a large plate with a smaller one—you can't fit more food on a smaller plate, so you end up eating less food at a time.
• Hormonal changes affect appetite in ways that dieting alone cannot achieve. A smaller stomach produces less of a hormone called ghrelin, which controls your appetite. Think of ghrelin as your body's hunger messenger - with fewer messenger cells; you don't get as many 'I'm hungry' signals throughout the day. This helps reduce those intense food cravings that make it hard to diet by cutting calories.

What happens during gastric sleeve surgery?

Let's look at how surgeons perform gastric sleeve surgery. The procedure typically takes less than two hours and uses small incisions—similar to other modern surgical techniques you might be familiar with, like laparoscopic gallbladder removal. The surgeon works with tiny instruments and a camera, meaning you'll have just a few small cuts instead of one large incision.

During the surgery, the team carefully removes the outer part of your stomach while keeping your digestive pathway exactly as it is naturally. This straightforward approach is one reason many surgeons prefer this type of weight loss surgery - it changes the size of your stomach without rerouting any part of your digestive system.

Recovery from gastric sleeve surgery: what to expect

Recovery from gastric sleeve surgery happens in stages. Most people stay in the hospital for two to three days after surgery. Many return to work after 2-4 weeks.

During the first few weeks, the diet progresses gradually from clear liquids to pureed foods and finally to solid foods. This careful progression allows proper healing and helps people adjust to their new stomach size.

The changes after gastric sleeve extend beyond just eating less food.

Successful long-term results typically involve:

Learning new eating habits, such as:

• Taking smaller bites and chewing thoroughly
• Eating slowly and stopping when feeling satisfied
• Choosing nutrient-dense and protein-rich foods
• Avoiding drinking with meals

Making lifestyle modifications, including:

• Regular physical activity as approved by healthcare providers
• Taking recommended vitamin and mineral supplements
• Regular medical follow-up visits
• Participating in support groups or counseling when needed

How successful is gastric sleeve surgery for weight loss?

Most people lose a significant amount of their excess weight after gastric sleeve surgery, typically 60-70% within the first year. Many people also experience improvements in obesity-related health conditions like type 2 diabetes, high blood pressure, sleep apnea, and fatty liver disease.

Teens who had bariatric surgery (gastric sleeve and gastric bypass surgery) saw lasting benefits ten years later, according to a large 2024 clinical study funded by the National Institutes of Health. In the study, young people who had surgery around age 17 maintained a 20% lower body mass index. More than half no longer had common weight-related health problems like type 2 diabetes, high blood pressure, and high cholesterol. Both gastric sleeve and bypass surgeries showed these positive results.

However, it's important to understand that the surgery is a weight loss tool, not a guaranteed solution. Success requires a commitment to lifestyle changes and regular medical follow-up.

What are the risks and challenges of gastric sleeve surgery?

Like any surgery, gastric sleeve comes with potential risks and challenges you should understand. While serious complications are rare, let's look at what you might experience both during and after surgery.

Short-term risks (within the first month)

• Bleeding or infection: Just like a cut that needs time to heal, your stomach needs time to recover. Your surgical team carefully monitors for any signs of bleeding or infection, which can usually be treated effectively if caught early.
• Reaction to general anesthesia: Some people might feel nauseous or dizzy from the medications used during surgery. Your anesthesia team creates a personalized plan based on your health history to minimize these risks.
• A leaky gut (gastric sleeve leak): Think of your stomach like a carefully sealed container. Sometimes, tiny gaps can form where the surgical cuts were made, but surgeons check thoroughly for these during the procedure and monitor you closely afterward.
• Blood clots: When you're less active right after surgery, blood can move more slowly through your legs. That's why your care team will have you up and walking as soon as it's safe, usually the day after surgery.

Long-term complications

• Acid reflux: The smaller stomach shape can sometimes let stomach acid travel upward more easily. Many people find relief through medication and learning which foods trigger their reflux.
• Nutrient deficiencies: Your smaller stomach means you eat less food overall. Think of vitamins as your daily insurance policy - taking them helps prevent deficiencies that could affect your health.
• Medication absorption: Some medicines might not work the same way in your smaller stomach. Your healthcare team will help adjust your medications if needed.
• Dehydration: With a smaller stomach, you'll need to sip water throughout the day instead of drinking large amounts at once. Many people find that carrying a water bottle helps them stay on track.

Disclaimer: This is not a complete list of surgery risks and should not be taken as medical advice. Consult your healthcare team for comprehensive information about risks, benefits, and considerations specific to your situation.

Frequently Asked Questions (FAQs) about gastric sleeve

How much weight can I expect to lose?

How much weight you might lose after gastric sleeve surgery depends on your unique situation, but here's what we know: most people lose about 60-70% of their excess weight in the first year. Like any weight loss journey, keeping the weight off means creating new, healthy habits that work for you and staying connected with your healthcare team.

Your healthcare provider can provide more detailed guidance on what to expect and help you prepare mentally before surgery.

Will my insurance cover the surgery?

Most insurance plans help cover gastric sleeve surgery (sleeve gastrectomy), but they may request a paper trail showing that you have tried other weight loss methods first and that you have weight-related health problems. Think of it like building your case for bariatric surgery.

It's also worth checking with your insurance company about support services like a bariatric nutritionist dietitian.

What about pregnancy after surgery?

"Women are typically advised to wait 12-24 months after surgery before becoming pregnant," says Eapen, MD. "Many women have healthy pregnancies after gastric sleeve surgery, but close medical supervision is important. It's best to discuss your expectations about pregnancy with your gastric sleeve surgeon and learn your options."

Is the gastric sleeve procedure reversible?

No, once you have gastric sleeve surgery, it cannot be reversed because the surgeon removes about 80% of your stomach permanently. Think of it like altering a piece of clothing: once you cut away the fabric, you can't put it back exactly as it was.

That's why it's so important to take the time to explore this option with your healthcare team. They'll help you understand what the surgery means for your life, answer your questions, and make sure you feel confident about your decision before moving forward.

Remember, while the surgery is a powerful weight loss tool for many people with obesity and obesity-related health problems, it's a lifelong change that deserves careful thought and discussion.

Final thoughts

Gastric sleeve surgery is one of several options for managing obesity and excess body weight. Think of it as a tool that, when combined with healthy habits, can help you reach your health goals. Everyone's path to better health looks different - what matters is finding an approach that works for you.

Your next step? Talk with your healthcare team about whether this might be right for your situation.

Need help with your bariatric diet before or after gastric sleeve surgery? Find a bariatric dietitian near you.

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.