Bariatric surgery can help you lose weight. However surgery always involves risk, and weight loss procedures require permanent changes post-op. For this reason, most doctors will not consider surgery unless a person:

• Has a body mass index (BMI) greater than 40, or is more than 100 pounds overweight, or has a BMI greater than 35 and has an obesity-related disease.
• Has tried conventional weight loss strategies with little or no success.
• Has the capacity to change their diet to ensure surgery works and prevent complications.

Most people have heard of gastric bypass, the most popular form of weight loss surgery. But it's just one option. Here are the four main weight loss surgery options, so you can choose the right one for your lifestyle.

Gastric Bypass

According to the American Society for Metabolic and Bariatric Surgery (ASMBS), gastric bypass surgery divides a portion of the stomach away from the rest of the stomach, creating a small pouch. This causes food to bypass the rest of the stomach. A surgeon connects the small intestine to this newly created stomach. This creates a much smaller stomach, forcing you to eat smaller meals.

The smaller stomach and small intestine are less able to digest and absorb food, which may mean that a person extracts less nutrition from their smaller meals.

Most people lose significant weight with this routine. However, surgery requires you to make long-term changes to your diet. Without proper support, a person may become deficient in key nutrients. Gastric bypass is also a relatively complex procedure that requires a longer hospital stay.

Sleeve Gastrectomy

Sleeve gastrectomy removes about 80 percent of the stomach. This has a similar effect to gastric bypass, reducing the amount of food a person can eat. Because the stomach is smaller, surgery also affects the production of various hormones. This can help you feel fuller faster, and may reduce some food cravings.

Sleeve gastrectomy works about as well as gastric bypass, and is a less invasive procedure that requires a shorter hospital stay, according to the ASMBS. In addition to supporting weight loss, it can help reduce many weight loss challenges by causing feelings of fullness and reducing food cravings. Like gastric bypass, it can cause long-term nutritional deficiencies. It is also irreversible.

Adjustable Gastric Band

The adjustable gastric band wraps a band around the upper portion of the stomach. This shrinks the usable part of the stomach, producing similar effects to gastric bypass and sleeve gastrectomy. A doctor tightens the band over time, so the effect is more gradual than traditional surgeries.

Research suggests that the gastric band may not reduce the amount of food a person can consume. Food may pass through the band. So instead, the band may work by reducing hunger.

The adjustable gastric band is a reversible procedure, with the lowest rate of early complications of any weight loss surgery. It is also less invasive, and presents a lower risk of nutritional deficiencies. However, it also has the highest rate of subsequent surgeries, and weight loss tends to be slower.

Biliopancreatic Diversion With Duodenal Switch

Biliopancreatic diversion with duodenal switch (BPD/DS), usually just called duodenal switch surgery, has two components, according to Johns Hopkins Medicine.

First, a surgeon creates a smaller stomach, similar to the procedure used for sleeve gastrectomy. Then the surgeon removes a portion of the small intestine, reducing the amount of food you can absorb. Together, these interventions create a smaller stomach that can accommodate less food, while preventing the body from gaining as much weight as it might usually gain from the food you do eat.

Patients typically lose more weight with the duodenal switch than they do with other procedures. This surgery also offers the best chance of improving weight-related complications like diabetes. It requires less dietary management, and over time, most people can eat relatively normal meals. However, it also has the highest rate of complications and death, presents a high rate of nutritional deficiencies, and requires ongoing follow-up visits.

Source: WebMD