Sleeve Gastrectomy (also known as gastric sleeve or vertical sleeve gastrectomy) is a highly effective weight loss procedure that works in multiple ways to achieve sustained weight loss and improve or resolve obesity-related health conditions. Here’s a detailed look at how it works:
1. Restriction: Smaller Stomach, Controlled Portions
The procedure reduces the stomach’s size by about 80%, leaving a narrow, banana-shaped tube with an average volume of 150 mL. This smaller stomach limits the amount of food you can eat at one time, helping you feel full after smaller meals. Unlike gastric banding, which creates a single point of restriction, the entire stomach tube in sleeve gastrectomy is uniformly narrow but flexible. This allows patients to eat normal foods—just in smaller portions—while feeling satisfied. It’s particularly effective for individuals who tend to overeat or consume large meals.
2. Reduced Ghrelin Levels: Curbing Hunger
Ghrelin, often called the "hunger hormone," is primarily produced in the part of the stomach that is removed during sleeve gastrectomy. This hormone stimulates appetite, promotes fat storage, and increases food cravings, especially during dieting or starvation. After sleeve gastrectomy, ghrelin levels drop significantly, reducing hunger and making it easier to stick to smaller, healthier meals. This hormonal change helps patients avoid the constant hunger pangs often experienced with traditional diets.
3. Faster Stomach Emptying: The Ileal Brake Effect
After sleeve gastrectomy, the stomach empties more quickly into the small intestine. This rapid emptying triggers the release of gut hormones like GLP-1 and PYY from the ileum (the last part of the small intestine). These hormones play a key role in:
- Inducing satiety: Helping you feel full and satisfied after meals.
- Suppressing appetite: Reducing the desire to eat between meals.
- Slowing gut motility: Increasing meal satisfaction and reducing the urge to overeat.
This phenomenon, known as "The Ileal Brake," mimics some of the effects of gastric bypass surgery and contributes to the procedure’s success.
4. Improved Insulin Sensitivity and Diabetes Control
One of the most remarkable benefits of sleeve gastrectomy is its impact on type 2 diabetes and insulin resistance. These improvements often occur even before significant weight loss takes place. Here’s how it works:
- Reduced Ghrelin: Ghrelin is known to promote insulin resistance and block insulin release. Lower ghrelin levels after surgery enhance the pancreas’s ability to produce insulin in response to meals.
- Incretin Effect: The increased levels of GLP-1 and PYY after surgery further stimulate insulin secretion, improving blood sugar control.
- Weight Loss: As patients lose weight, insulin resistance decreases, and diabetes symptoms often improve or resolve completely.
5. Increased Bile Acids: Boosting Metabolism
Bile acids, which are essential for fat digestion, also act as hormones that influence metabolism and fat storage. After sleeve gastrectomy, bile acid levels in the blood increase. These acids bind to FXR receptors throughout the body, leading to:
- Increased metabolic rate: Helping the body burn calories more efficiently.
- Reduced fat storage: Promoting weight loss and preventing weight regain.
- Stimulation of gut hormones: Further enhancing the release of GLP-1 and PYY, which contribute to satiety and appetite control.
Emerging research also suggests that changes in gut micro-organisms (the gut microbiome) after sleeve gastrectomy may play a significant role in weight loss and metabolic improvements.
Why Sleeve Gastrectomy is Effective
Sleeve gastrectomy is more than just a restrictive procedure—it’s a metabolic surgery that addresses multiple factors contributing to obesity and related health conditions. By combining portion control, hormonal changes, and metabolic improvements, it offers a comprehensive approach to weight loss and long-term health.
Key Takeaways
- Portion Control: The smaller stomach helps patients eat less while feeling satisfied.
- Hormonal Changes: Reduced ghrelin levels curb hunger, while increased GLP-1 and PYY enhance satiety.
- Metabolic Benefits: Improved insulin sensitivity, diabetes control, and increased bile acids contribute to weight loss and overall health.
- Long-Term Success: The procedure supports sustainable weight loss and improved quality of life.
