Weight loss surgery—also known as bariatric surgery—is a broad term that describes surgical procedures designed to help you lose weight. Weight loss surgeries do this by adjusting the stomach and intestines to restrict food intake and calorie absorption. These procedures are meant to help manage and treat health conditions related to obesity when other treatments haven’t worked well enough.
More than 40% of adults in the United States have obesity, but not all of them are candidates for weight loss surgery. Healthcare providers may suggest weight loss surgery as an option if you have more severe obesity and also haven’t lost enough weight through diet, exercise, or weight loss medication.
The choice to undergo weight loss surgery is a serious decision. It’s important to talk to your healthcare provider and a surgeon to decide if it’s a good choice for you.
Eligibility Criteria
Most healthcare providers use body mass index (BMI) as a guide, along with your health history of conditions like type 2 diabetes or hypertension (high blood pressure), to determine whether weight loss surgery may be a good fit. In general, you need to meet the following criteria to be eligible for a weight loss surgery:
- BMI of at least 40: This BMI is classified as severe obesity, also known as morbid obesity or class 3 obesity.
- BMI of at least 35 with a chronic health condition linked to obesity: These include conditions such as heart disease, type 2 diabetes, or sleep apnea.
- BMI of at least 30 with unmanaged type 2 diabetes: You may be eligible if you have type 2 diabetes that medical treatments or lifestyle adjustments haven’t helped control.
Other factors that your healthcare provider may consider include:
- The rest of your medical history
- Your age
- Your risk of complications during surgery
Weight loss surgery may benefit your overall health and well-being for several reasons. For example, if you have weight loss as a result of surgery, it often improves other health conditions related to obesity. Examples of these conditions include:
- Type 2 diabetes
- Heart disease
- Sleep apnea
- High blood pressure
- High cholesterol
- Osteoarthritis or joint pain
- Asthma
- Gastroesophageal reflux disease (GERD)
- Urinary incontinence (leaking urine)
Carrying less weight on your body can make daily movement and physical activity easier, which can help improve your mood and overall quality of life. You may not have to take as many prescription medications after weight loss. This may also add to your quality of life, lower healthcare costs, and add years to your life if you have severe obesity.
There are several types of weight loss surgeries. Each changes the digestive tract to decrease how much food you can consume. All are considered major medical procedures for mitigating the health complications of obesity.
Roux-en-Y Gastric Bypass
Roux-en-Y gastric bypass is also called gastric bypass surgery.
How it works: The surgeon creates a small pouch out of the upper part of your stomach, then connects it to the lower part of your small intestine.
The effect: Your stomach is smaller. You won’t be able to eat as much, and you’ll feel fuller sooner. The food that you do eat will bypass most of your stomach and small intestine, which means you’ll absorb fewer calories. Gastric bypass surgery also affects your appetite and metabolism by altering hormones and bacteria naturally found in the digestive tract.
Sleeve Gastrectomy
Sleeve gastrectomy is also called vertical sleeve gastrectomy or gastric sleeve surgery.
How it works: A large portion of your stomach is removed. You’ll be left with a small, tube-shaped section of the stomach that’s surgically closed with staples.
The effect: Because your stomach is physically smaller, you’ll feel fuller sooner after eating. Like gastric bypass, this procedure also impacts appetite and metabolism by affecting your hormones and bacteria in your digestive tract.
Biliopancreatic Diversion With Duodenal Switch (BPD/DS)
Biliopancreatic diversion with duodenal switch (BPD/DS), also known as a mixed surgery, may help you lose more weight compared to other options. But it’s also riskier, with a higher likelihood of surgical complications and nutritional deficiencies. It’s usually reserved for people who have severe obesity along with other conditions.
How it works: This surgery involves two different procedures. Your surgeon will first do an initial procedure similar to a sleeve gastrectomy. Then, they’ll do another surgical procedure that splits your small intestine into two tracts.
Effects: One of the tracts directs food to bypass much of the small intestine, which reduces the calories and nutrients your body can absorb. The other tract allows digestive fluids to flow from the stomach to the colon, where the fluids meet with food.
Single-Anastomosis Duodeno-Ileal Bypass With Sleeve Gastrectomy (SADI-S)
The single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is similar to the BPD/DS, but it’s simpler and requires less surgical time. It’s available as a first surgery, but also for people who have already had a sleeve gastrectomy and are interested in further weight loss.
How it works: The surgeon begins by creating a smaller stomach pouch, similar to the procedure used in sleeve gastrectomy. From there, they divide the first portion of the small intestine and then connect a loop of the small intestine to the stomach.
Effects: Food goes through the pouch and straight into the lower part of the small intestine, where it mixes with digestive fluid and allows for enough nutritional absorption.
Weight loss surgery can be life-changing for many people. However, it’s not an instant fix for obesity. Here’s what you can expect after a procedure.
Recovery and Post-Surgery Care
Talk to your healthcare provider about how long you’ll need to rest after your procedure. They can share more about the type of physical activity that’s appropriate in the initial stages, including how much you can walk around your home.
After following a liquid diet immediately after surgery, you can expect your healthcare provider to recommend a diet of soft foods for several weeks. Eventually, your healthcare provider will also instruct you on when you can safely eat small meals of solid foods. You’ll likely also need to take dietary supplements to ensure your body gets the nutrition it needs.
Results and Long-Term Success
The exact amount of weight that people lose after surgery can vary based on the person and the type of surgery performed. In many cases, you can expect to lose 10-20 pounds per month during the first year after surgery, with weight loss gradually decreasing over time.
Keep in mind that it’s possible to regain a small amount of weight. This is where follow-up care and monitoring comes in. Staying consistent with your appointments, check-ins, and recommended nutrition and exercise plans can help you lose more weight and avoid potential complications.
Weight loss surgery itself comes with risks that your healthcare provider will discuss with you, such as:
- Infection
- Bleeding
- Blood clots
- Leaking from the surgical site
- Diarrhea
Weight loss surgery also carries the risk of long-term complications, which may include:
- Anemia and osteoporosis: These may happen if you don’t absorb enough nutrients.
- Gallstones: These are hardened deposits that may develop in your gallbladder after you lose a lot of weight quickly.
- Small bowel obstruction: This is a condition in which your bowel becomes dangerously blocked.
- Strictures: These narrowings of the stomach or the pathway between the stomach and small intestine can make it difficult to swallow and eat.
- Hernias: These may occur at the surgical incision site or in the abdomen. Hernias are protrusions of internal organs through the muscle wall that may require surgery for repair.
- Trouble digesting alcohol: Gastric bypass, in particular, may affect how your body absorbs and breaks down alcohol.
A small portion of people who get weight loss surgery require another surgery or hospitalization within five years. These follow-up procedures are more common in people who get gastric bypass surgery compared to gastric sleeve surgery.
Several types of weight loss surgeries are available if you meet eligibility requirements. These surgeries of the digestive tract help you eat less and feel fuller, while the body’s ability to digest food and calories adjusts. Different benefits and risks come with each, which a healthcare provider can discuss with you if you’re considering weight loss surgery. A successful weight loss journey will also require lifestyle, dietary, and exercise changes for the best results.