The Roux-en-Y bypass is the most common, and safest, weight loss surgery used by doctors to help obese people control their caloric intake. Other measures may be used, however, including biliopancreatic diversion, the Mason procedure, and sleeve gastrectomy. All these procedures can help obese people lose anywhere from 70 to 116 pounds (32 to 53 kg) of weight within three years.
The Roux-en-Y bypass is initiated by making a small incision into the stomach, to divide it into two pouches — a small, walnut-sized pouch and a big pouch. A section of the small intestine is then connected to the smaller pouch. After the surgery, any food or liquids consumed will pass through the small pouch, severely limiting a person's ability to consume food. At the most, doctors estimate people can consume a maximum of 1,000 calories per day with their new, smaller stomach.
This procedure is considered the safest form of weight loss surgery because very few incisions are made into the stomach, limiting the risk for infection. People who get this type of surgery typically recover faster and report experiencing less pain. It also helps obese people lose more weight when compared to other procedures. Some estimates say people can lose up to 80 percent of their total body weight after one year.
The biliopancreatic diversion procedure also divides the stomach into a smaller and bigger pouch, connecting the small intestine to the smaller pouch. It differs from Roux-en-Y bypass because the larger pouch is removed — it isn't kept inside the body. This makes this type of weight loss surgery impossible to reverse.
There have been numerous health problems caused by this surgery. Many people suffer from nutritional deficiencies and poor intestinal food absorption, making it necessary to use vitamins to prevent malnutrition, often above the recommended daily allowance (RDA). It can also cause anemia, and to some extent, osteoporosis. This type of weight loss surgery is rarely used because the complications associated with it.
The Mason procedure, better known as stomach stapling, shrinks the stomach by using surgical staples and a medical band on the stomach to create a smaller stomach pouch, which is then connected to the small intestine. Unlike biliopancreatic diversion, the remaining portion of the stomach is not removed, making it a somewhat safer procedure. It is also less effective, and many people end up gaining weight because the surgery makes it harder to digest fibrous, healthy foods. About 30 percent of people who undergo this surgery maintain a normal weight, with 80 percent reporting some weight loss.
Sleeve gastrectomy differs from the other procedures because surgeons remove the middle portion of the stomach, leaving the top and bottom of it intact. These two portions are then connected, creating a tubular-shaped stomach which can accommodate small amounts of food. People who undergo this surgery experience fewer side effects, and typically lose 33 percent of their body weight within a year. The risk for malnutrition and poor food digestion is significantly decreased with this type of weight loss surgery.