Patient education: Weight loss surgery (The Basics)

What is weight loss surgery? — Weight loss surgery, sometimes called "bariatric surgery," is surgery to help you lose weight. It works by making you take in fewer calories and nutrients.

Who can have weight loss surgery? — Doctors use a measure called "body mass index," or BMI, to decide who is underweight, at a healthy weight, or overweight. Your BMI will tell you which category you are in based on your weight and height (figure 1).

Weight loss surgery is appropriate only if you have not been able to lose weight in other ways and if you:

●Have a BMI above 40 and have not lost weight through diet, exercise, or weight loss medicines; or

●Have a BMI above 35 and also have a medical problem related to obesity, such as diabetes, heart disease, or high blood pressure

Are there different types of weight loss surgery? — Yes. There are many different types. The most common are (figure 2):

●Gastric bypass – Gastric bypass is short for "Roux-en-Y gastric bypass." It is sometimes called "RYGB." For this surgery, the doctor closes off part of the stomach, leaving only a small pouch for food. Then they connect the stomach pouch to the middle part of the small intestine. This allows food to "bypass," or go around, part of the stomach and small intestine.

There are other surgeries that are similar to gastric bypass in how they cause weight loss.

●Gastric sleeve – Gastric sleeve is a surgery that turns the stomach into something that looks like a sleeve. It is also called "sleeve gastrectomy." For this, the doctor removes a large portion of the stomach and leaves a narrow tube.

How is the surgery done? — In the US, almost all gastric bypass and gastric sleeve procedures are done as "laparoscopic" surgery. For laparoscopic surgery, the surgeon makes a small cut and inserts a narrow tool that has a tiny camera on the end into the belly. This tool is called a "laparoscope." It allows the surgeon to see inside the belly without opening it up all the way. Then they can do the surgery using other tools that fit through small openings in the belly. These tools can be controlled from the outside.

How do the different procedures compare? — Each type of weight loss surgery is different, and each has different benefits and downsides.

●Gastric bypass leads to more weight loss and works the fastest, but it also comes with more risks. It can also cause problems in how your body absorbs nutrients. As a result, it can lead to "nutritional deficiencies," meaning your body is missing important nutrients. This can sometimes make you sick. If you have gastric bypass, your doctor will monitor your nutrient levels afterward.

●Sleeve gastrectomy is less risky because it does not involve rerouting or cutting and reattaching the intestines. It is also less likely to cause problems with how you absorb nutrients.

How do I know which surgery is best for me? — The decision about which type of surgery to have is important. Discuss your choices with your doctor.

If you have different options, ask the following questions:

●About how much weight can I expect to lose with each option?

●How long will it take me to lose the weight?

●What are the risks of each option for someone like me?

●What changes will I need to make to my diet and lifestyle with each option?

Whatever you decide, make sure your surgeon is very experienced with weight loss surgery. Also, check with the staff at your treatment center or make sure it is a certified "Center of Excellence." Those centers have a team of nurses and doctors who specialize in taking care of patients like you. If you are at all unsure about your decision, you can ask for an opinion from another doctor. Most hospitals that have experience with weight loss surgery offer patient education sessions. In these sessions, you can learn more about weight loss surgery and your options.

What are the benefits of surgery? — In addition to helping you lose weight, surgery can help improve or even get rid of certain health problems. These include:

●Diabetes

●High blood pressure

●High cholesterol

●Sleep apnea, a disorder that causes you to stop breathing for short amounts of time while you sleep

●Fatty liver disease

What are the risks of surgery? — The risks of surgery are different depending on:

●What type of weight loss surgery you have

●Whether your surgery is open or laparoscopic

●Your age and overall health

●How experienced your surgeon is

In general, the risks could include:

●Bleeding

●Infection inside the belly or in the wounds from surgery

●Leaks from the incisions on the stomach or intestine

●A blockage or tear in the intestines

●Problems with the heart or lungs, including blood clots

●Gallstones

●Nutritional problems

●Severe diarrhea

●The need for more surgery

As with any kind of surgery, it is possible for these procedures to lead to serious problems or even death. Death following weight loss surgery is very rare. But it's still important to talk to your doctor about all the possible risks of each type of surgery.

Will I need to change the way I eat after surgery? — Yes. Work with a dietitian (food expert) to learn how your diet should change.

You will need to eat healthy foods that "work with" your surgery. For example, you should choose foods high in protein and low in fat and calories. You should also avoid liquid foods that are high in calories, such as ice cream. Being careful about what you eat will make you more likely to keep a healthy weight after surgery.

If you have weight loss surgery, you will need to avoid certain foods that could make you sick. You will also probably need to take special multivitamins with minerals. That's because weight loss surgery, especially gastric bypass, can make it hard for your body to get all the nutrition it needs. You must keep taking the vitamins for the rest of your life. Your body will always need them to stay healthy.

More on this topic

Patient education: Weight loss treatments (The Basics)
Patient education: Minimally invasive surgery (The Basics)
Patient education: Health risks of obesity (The Basics)
Patient education: Care after weight loss surgery (The Basics)

Patient education: Losing weight (Beyond the Basics)
Patient education: Weight loss surgery and procedures (Beyond the Basics)