What is Sleeve Gastrectomy? The Stomach Reduction Process and Nutrition

Sleeve gastrectomy is an effective bariatric surgery method where a large portion of the stomach is surgically removed, reshaping the remaining part into a long, thin tube. This procedure significantly reduces stomach volume and decreases the release of appetite hormones, helping to achieve sustainable weight loss. It stands as a reliable surgical option for patients who have not been able to reach their target weight through diet and exercise alone.

• Approximately seventy to eighty percent of the stomach is removed using a laparoscopic (closed) approach.
• Because the level of the appetite hormone (ghrelin) drops, you feel full much faster.
• It is among the primary options for patients with a body mass index of 35 and above.
• The recovery process is swift, with a typical hospital stay of just two or three days.
• Post-surgery nutrition progresses in three distinct stages: liquid, puree, and solid.

What is Sleeve Gastrectomy (Stomach Reduction)?

The question of what a sleeve gastrectomy entails is often the first thing researched by many people looking to lose weight permanently. Known medically as a sleeve gastrectomy, this stomach reduction surgery is one of the most frequently preferred methods in obesity treatment. During the procedure, a large section of the stomach is divided vertically and removed, leaving behind a new, banana-shaped stomach with a volume of roughly 100 to 150 millilitres.

This surgical intervention does more than just physically reduce the stomach's capacity; it also alters the balance of hormones that regulate hunger. The level of ghrelin (the hunger hormone), which is produced in the upper part of the stomach that gets removed, drops significantly. As a result, patients feel far less hungry after surgery compared to before, and they easily reach satiety with small portions. Thanks to both its mechanical and hormonal effects, it is a highly successful method for achieving long-term weight control.

Who is a Candidate for Sleeve Gastrectomy?

When making the decision for bariatric surgery, a patient's weight, overall health, and previously attempted weight-loss methods are evaluated in detail. The answer to who can undergo a sleeve gastrectomy relies on clear criteria set by international health standards. The primary measure is a person's body mass index (BMI).

Individuals with a body mass index of 35 kg/m² or higher, who have not been able to lose weight permanently through diet or exercise, are suitable candidates for this surgery. Additionally, patients with a BMI between 30 and 35 who suffer from obesity-related conditions such as type 2 diabetes, sleep apnea, high blood pressure, or severe joint disorders may also undergo the procedure. Generally performed on people between the ages of 18 and 65, this surgery can sometimes be offered to younger or older patients in special circumstances, subject to the approval of medical boards.

The Pre-Surgery Preparation Process

A successful stomach reduction surgery requires a meticulous preparation phase. When you visit the hospital, a general surgeon will examine you and initiate a comprehensive screening to determine your suitability for the operation. During this process, tests such as blood work, a chest X-ray, an ECG, an abdominal ultrasound, and an endoscopy are performed to inspect the condition of your stomach and other organs.

Alongside physical examinations, you will be thoroughly evaluated by specialists in cardiology, endocrinology, pulmonology, and psychiatry. About one or two weeks before the surgery, you will be asked to start a special pre-operative diet designed to shrink the size of your liver and minimise surgical risks. This diet typically consists of high-protein and low-carbohydrate foods. Furthermore, if you smoke, quitting at least three weeks prior to the operation is a critical step for your recovery process.

The Surgery and the Advantages of Laparoscopic Surgery

Bariatric surgery is performed under general anaesthesia using a laparoscopic, or closed, surgical technique. Special surgical instruments and a high-resolution camera are inserted through four or five small incisions in the abdomen, ranging from half a centimetre to one centimetre in diameter. Watching the inside of the abdomen on a monitor, the surgeon cuts away the large portion of the stomach and seals the remainder using a stapling method.

The procedure takes about one to one and a half hours on average. The greatest advantage of laparoscopic surgery is that it causes far less tissue trauma compared to open surgeries. Thanks to the small incisions, post-operative pain is kept to a minimum, the risk of wound infection drops, and a better cosmetic result is achieved. Patients are usually encouraged to start walking just a few hours after surgery, and the recovery process progresses quite rapidly.

Post-Surgery Nutrition and Recovery

In the post-operative period, you must completely change your eating habits to allow your new stomach to heal and to protect the staple line. The post-sleeve gastrectomy nutrition process advances in three main stages under the guidance of expert dietitians.

Liquid Diet Stage

The first two weeks following surgery make up the liquid diet stage. During this time, only clear, grain-free liquids such as water, sugar-free compotes, beef or chicken broth, lactose-free milk, and ayran (a traditional Turkish yogurt drink) are consumed. The goal is to ensure the stomach heals without being overworked and to prevent dehydration. Liquids must be sipped slowly.

Puree Diet Stage

In the third and fourth weeks, you transition to a puree diet. Fork-mashed eggs, strained cheese, yogurt, blended vegetable dishes, and fruit purees are the staple foods of this phase. Portions are very small, and food must be consumed slowly and chewed thoroughly. To avoid straining the stomach, soft foods without any solid chunks are preferred.

Transition to Solid Foods

By the end of the first month, you gradually begin eating solid foods. However, the rule of never consuming solid and liquid foods at the same time applies for life. You must stop drinking liquids half an hour before meals and wait until half an hour after eating to drink again. Eating a protein-rich diet is a fundamental rule to prevent muscle loss.

Expected Weight Loss Timeline and Benefits of the Surgery

Following a stomach reduction surgery, weight loss is quite rapid in the first few months and continues at a slower pace over time. During the first month, patients typically lose ten to fifteen percent of their excess weight. By the end of the third month, this rate reaches around thirty percent, and by the sixth month, fifty percent. By the end of the first year, patients have generally shed seventy to eighty percent of their excess weight.

This rapid and effective weight loss provides a major advantage in treating obesity-related comorbidities. Blood sugar levels in type 2 diabetes patients quickly return to normal, while issues like hypertension and sleep apnea are largely resolved. Joint pain eases, mobility increases, and the patient's overall quality of life improves significantly.

Sleeve Gastrectomy Risks and Complications

As with any major surgical intervention, bariatric surgery carries certain risks. Among the risks of sleeve gastrectomy, the most critical condition to watch for is a leak from the staple line. Although the incidence is less than one percent, early detection and intervention are of vital importance.

Other possible complications include bleeding, wound infection, blood clots in the lungs or leg veins (embolism), and adverse reactions to anaesthesia. In the long term, issues such as vitamin and mineral deficiencies due to inadequate nutrition, gallstone formation, or stomach stretching can occur. To minimise these risks, the surgery must be performed in a fully equipped hospital by an experienced surgical team, and post-operative follow-ups must never be neglected.

When to See a Doctor

During the recovery process, certain symptoms may require emergency medical intervention. Correctly reading the signals your body sends in the post-operative period and seeking professional help without delay is a vital step. If you experience any of the following symptoms, you should immediately call the 112 emergency hotline or visit the nearest fully equipped healthcare facility:

• A persistent fever of 38.5°C or higher
• Sudden, worsening, and sharp pain in the abdominal area
• Continuous vomiting and a complete inability to keep liquids down
• Shortness of breath, chest pain, or palpitations
• Excessive redness, swelling, increased warmth, or foul-smelling discharge at the incision sites
• Sudden swelling, redness, and pain in the legs

These symptoms can be warning signs of serious complications such as a leak, infection, or a blood clot (embolism). Early intervention is crucial to eliminate potential risks.

The Process at BHT CLINIC

At BHT CLINIC İstanbul Tema Hastanesi, bariatric surgery processes are conducted with a multidisciplinary approach, always prioritising the safety and comfort of our patients. Our experienced physicians in the General Surgery department will complete your detailed pre-operative tests to create the most suitable treatment plan for you. In our JCI-accredited hospital, we provide care that meets international quality standards.

In the post-operative period, our dietitians and psychologists continue to support you as you adapt to your new lifestyle. In any emergency, our Emergency Medicine department, which operates 24/7 without interruption, is ready for immediate intervention with its expert staff. To take a step towards a healthier future and schedule a detailed evaluation appointment, you can visit our appointment page.

Frequently Asked Questions

Can I regain weight after the surgery?

Because the stomach is a flexible organ, it can expand slightly over time. Although it is very difficult to gain weight during the first two years after surgery, the risk of regaining weight does emerge if dietary rules are ignored and high-calorie, unhealthy foods are continually consumed.

Is there an age limit for a sleeve gastrectomy?

Generally, individuals who are over 18 and under 65 years of age are suitable candidates for this surgery. However, if a person faces severe life-threatening risks due to obesity, the operation can be performed on patients outside these age limits following a detailed evaluation and approval by medical boards.

How does the surgery affect private life?

The correction of hormone balance alongside weight loss has positive effects on sexual life. While obesity-induced reductions in libido improve in men, menstrual irregularities and fertility issues linked to excess weight in women show significant improvement.

Is exercise mandatory after surgery?

Exercise is always necessary for a healthy life. Engaging in regular physical activity after surgery accelerates the weight loss process, prevents muscle loss, minimises skin sagging, and helps you feel psychologically better thanks to the release of endorphins.

This article is for informational purposes only; please be sure to consult your physician for diagnosis and treatment.