Metabolic and bariatric surgery is a medical intervention for individuals with severe obesity, aiming for substantial and lasting weight loss. It also frequently improves various obesity-related health conditions. It is a comprehensive treatment strategy, emphasizing long-term lifestyle adjustments. The procedures involve modifications to the digestive system, which can alter how the body processes food and regulates hormones.
Types of Procedures
Sleeve gastrectomy, or gastric sleeve, reduces stomach size. About 80% of the stomach is removed, creating a smaller, banana-shaped pouch. This limits food intake, promoting earlier satiety. It also influences hunger hormones like ghrelin, decreasing appetite.
Roux-en-Y gastric bypass is a complex procedure involving stomach reduction and small intestine rerouting. A small stomach pouch, about the size of a walnut, is created. This pouch connects directly to a lower section of the small intestine, bypassing much of the stomach and upper small intestine. This bypass reduces food intake and nutrient absorption, impacting gut hormones to lessen hunger and increase fullness.
The adjustable gastric band, or Lap-Band, places an inflatable silicone band around the upper stomach. The band creates a small pouch, and its opening can be adjusted by injecting or removing saline through a port under the skin. This restricts food intake, promoting fullness with smaller amounts.
Biliopancreatic diversion with duodenal switch (BPD/DS) is an involved procedure combining stomach reduction with significant intestinal rerouting. It begins with a sleeve-shaped stomach pouch, similar to sleeve gastrectomy. About 75% of the small intestine is bypassed, connecting the new stomach pouch to the latter part of the small intestine. This extensive rerouting significantly reduces calorie and nutrient absorption, leading to substantial weight loss and potent effects on hunger and blood sugar.
Eligibility and Candidate Selection
Candidates for metabolic and bariatric surgery typically meet specific Body Mass Index (BMI) thresholds. Generally, a BMI of 40 or higher qualifies, or 35 or higher with significant obesity-related health conditions. Some guidelines also consider individuals with a BMI of 30 or higher if they have at least one obesity-related condition and have not achieved sustained weight loss through non-surgical methods.
Unsuccessful non-surgical weight loss attempts (e.g., diet, exercise, medications) are usually a prerequisite. A comprehensive evaluation by a multidisciplinary team is also standard. This team includes a dietitian, a psychologist or mental health specialist, and the bariatric surgeon.
This assessment evaluates the patient’s medical history, physical health, psychological readiness, and commitment to long-term lifestyle changes. The multidisciplinary approach identifies underlying issues that might affect surgical outcomes and ensures the patient is prepared for the journey.
Benefits Beyond Weight Loss
Metabolic and bariatric surgery offers significant health improvements beyond weight reduction, addressing underlying metabolic dysfunction associated with obesity. Procedures can lead to substantial improvements or even remission of type 2 diabetes. Studies indicate 33% to 90% of individuals experience diabetes remission within one year post-surgery.
The surgery also positively impacts high blood pressure (hypertension), with 30% to 50% remission rates, and can reduce the number of medications needed. High cholesterol (dyslipidemia) often improves, with studies showing better levels after surgery compared to lifestyle modifications alone.
Sleep apnea symptoms frequently diminish or resolve following bariatric surgery due to weight loss, with 80% to 85% remission rates reported five years post-surgery. Joint pain and mobility also improve as reduced body weight lessens stress on joints. These health benefits contribute to enhanced quality of life and may extend longevity.
Navigating the Surgical Journey
The journey begins with extensive pre-operative preparation, involving various evaluations and lifestyle adjustments. Patients undergo health screenings (blood tests, imaging, endoscopy) to confirm suitability. Dietary changes (e.g., reducing saturated fats, refined carbohydrates, sugary beverages) are often initiated to prepare the body and reduce surgical risks.
Psychological evaluations are standard, assessing readiness for changes and identifying any emotional or mental health issues. Many programs require participation in educational sessions covering nutrition, exercise, and what to expect during and after the procedure. Patients are advised to cease smoking at least four weeks before surgery and may need to adjust medications.
Surgery is often performed laparoscopically through small incisions, under general anesthesia. The immediate post-operative period involves a brief hospital stay (one to two nights), focusing on pain management and early mobilization. Patients begin with a clear liquid diet, gradually progressing to full liquids, pureed foods, and eventually soft foods over several weeks, guided by a dietitian.
Long-term adherence to dietary guidelines is important, emphasizing small, frequent, high-protein meals and avoiding sugary or carbonated beverages. Lifelong vitamin and mineral supplementation (e.g., bariatric-specific multivitamin, calcium citrate, B-12) is necessary to prevent nutritional deficiencies due to altered absorption. Regular physical activity is encouraged, starting with light exercises like walking and gradually increasing intensity.
Potential challenges and risks include nutritional deficiencies (e.g., iron, B12, calcium), dumping syndrome (rapid emptying of stomach contents causing nausea, diarrhea, dizziness), and strictures or leaks at surgical sites. These complications underscore the importance of consistent medical follow-ups with the bariatric team (surgeons, dietitians, specialists) to monitor progress, manage issues, and provide ongoing support.