What is Bariatric Surgery? - Definition, Types, Requirements & Risks

Instructor: Virginia Rawls

Virginia has a master' degree in Education and a bachelors in Sports Medicine/athletic Training

Bariatric surgery is a medical term used for the various surgical procedures used to promote weight loss. In this lesson, we will explore what bariatric surgery is, the requirements to qualify for bariatric surgery, the different types of bariatric surgery and the risks associated with this type of surgery.

What is Bariatric Surgery?

Bariatric surgery is a surgery that is designed to lead to weight loss. There are actually four different types of bariatric surgical procedures that can be done to help patients achieve weight loss. These procedures will either shrink the stomach so that the patient can only eat small amounts of food at a time or will change the way that the digestive system can absorb the food the patient eats.

The average stomach can hold around three cups of food and/or liquid. When the stomach is shrunk during bariatric surgery, it usually will only then hold about a cup.

Absorption occurs in the digestive tract in the small intestine. Remember that the small intestine is divided into three sections - the duodenum, jejunum and ileum. If the stomach is removed from the duodenum and reattached to the jejunum or ileum, it decreases the amount of absorption that can occur from the foods we eat.


Not just anyone can walk into their doctor's office and say that they want to have weight loss surgery. Patients need to meet a list of criteria before they will be considered candidates for bariatric surgery. Here are some generally accepted requirements:

  • First, the patient has to be medically documented as being severely obese or have a medical condition related to being obese and have a BMI over 35. A patient is not considered severely obese until their BMI, (body mass index) is over 40.
  • Second, the patient needs to have tried to lose weight by other means. This usually includes healthy eating, dieting, exercising and attempting to make other lifestyle changes that would promote weight loss.
  • Third, the patient will need to attend classes to understand how his or her body will react to the surgery and how he or she will need to make drastic lifestyle changes so that the surgery will be effective.

Patient education is a vital part of long-term success after surgery. Some of the lifestyle changes usually required involve avoiding certain foods, eating limited quantities of food and regular exercise. Patients will also need to take prescription vitamins and minerals so that they will not have any deficiencies after the surgery.

Types of Bariatric Procedures

There are four different types of bariatric surgical procedures that can be done to promote weight loss.

Adjustable Gastric Band. This is commonly referred to as the band surgery. This is the most basic and easiest of surgeries to do. In this procedure, the surgeon places a band (similar in appearance to a rubber band) around the top portion of the stomach to create a pouch. This pouch serves as a new, smaller stomach. Patients usually feel fuller faster, causing them to eat less and lose weight. This band can be surgically removed at any time.


Roux-en-Y Gastric Bypass Surgery. This is commonly referred to as gastric bypass. There are two steps to this procedure. First, the surgeon will create a new smaller stomach. This is very similar to using the gastric band, but instead of a band, uses staples. This makes the procedure more permanent. Second, the surgeon will attach this new stomach to the jejunum. This causes the body to absorb fewer calories from the food that was eaten. Because of these two steps, this surgery is often highly effective in leading to weight loss for the patient.


Vertical Sleeve Gastrectomy. In this procedure, the surgeon removes up to 80 percent of the patient's stomach. The majority of the stomach is removed, so this is a permanent procedure. When the procedure is over, the stomach will almost resemble a banana shape.

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