An expert explains the pros and cons of bariatric surgery

By Natasha Persaud

So you want to shed excess pounds to look and feel better. Is weight loss surgery (also known as bariatric surgery) right for you? Scott Shikora, M.D., president-elect of the American Society for Metabolic and Bariatric Surgery, discusses surgery's risks and benefits, and what it takes to be successful:

Who is eligible for weight loss surgery?

"To be considered for bariatric surgery, your body mass index (BMI) needs to be at least 40, or 35 or higher if you have an obesity-related condition, such as type 2 diabetes, heart disease, or sleep apnea," Dr. Shikora says. If a person is five feet eight inches tall, that translates to weighing 262 pounds or more, or 230 pounds or more with a medical condition.

What is the right frame of mind to have?

"Candidates for surgery need to be prepared to make significant changes in their eating, exercise and lifestyle that will last the rest of their lives," Dr. Shikora says. That's why everyone goes through a readiness program prior to surgery. "Over a number of weeks, you learn dietary management, stress management and the principles of a healthy body image. You also prepare for the surgery itself. During that time, you may be asked to lose a certain number of pounds to decrease the risk of complications and speed recovery."

Research shows that people who are successful with weight loss surgery are motivated, willing to change and honest about their behaviors. They also have the support of family and friends.

What should I consider before deciding on surgery?

Ask yourself these questions, according to Dr. Shikora:

  • Have I exhausted all other reasonable methods of weight loss?
  • Do I fully understand the risks and requirements of surgery?
  • Am I going through difficult life circumstances, such as a divorce or caring for an elderly parent, that would make it difficult for me to follow through with the entire program (both before and after surgery)?
  • For women: Am I pregnant, or do I want to conceive in the next 18 months (the typical recovery period from surgery)?
  • Do I smoke, abuse alcohol or drugs? Kicking those habits requires you to change behaviors, which is similar to what you’ll need to do to achieve weight loss.

"For some people, having surgery right now isn’t a good idea, and it's better to wait," Dr. Shikora adds.

Can you explain the various weight loss procedures?

Here are the four most common:

Gastric bypass—"the gold standard in the U.S.," according to Dr. Shikora—reduces the capacity of the stomach and changes the way food passes through the small intestine. Since the stomach can’t store large amounts of food and the small intestine absorbs fewer calories, a person loses weight.

Adjustable gastric banding, the second most frequently done procedure in the U.S., involves looping an inflatable band around the stomach to create a bottleneck near the top; this makes it hard for a patient to overeat. The band can be adjusted—tighter or looser—to regulate eating and appetite.

It can also be removed altogether. Worldwide, gastric banding is the weight loss surgery most often performed.

Sleeve gastrectomy, which is increasing in popularity, according to Dr. Shikora, removes a good part of the stomach so that it resembles a tube or sleeve. It’s usually performed on super-obese or high-risk patients with the intention of performing a second surgery at a later time, either a gastric bypass or duodenal switch. However, the attitude is changing as the sleeve is demonstrating that it may be an effective stand-alone procedure.

Biliopancreatic diversion with duodenal switch removes a good part of the stomach and skips most of the small intestine, reconnecting it towards the end. This makes it hard to eat large amounts of food and to absorb calories. Used for extreme obesity, this procedure is less common than the others. There’s a greater potential for complications and for vitamin and protein malnutrition.

Note that each of these weight loss procedures might be an open surgery or a laparoscopic procedure that uses short incisions through which a special video camera is inserted.

There’s no one bariatric procedure that’s good for all patients, points out Dr. Shikora. "The procedure is chosen based on the surgeon’s expertise and the patient’s BMI, medical condition and preference."

How much weight will I lose through surgery?

The amount of weight loss depends, in part, on the procedure. Surgeries that rearrange the small intestine, called malabsorptive procedures, tend to produce more weight loss—but they also carry more risks. These include the gastric bypass and biliopancreatic diversion with duodenal switch.

On average, patients may lose 30 to 50 percent of their excess weight in the first six months and 77 percent of excess weight within 12 months of weight loss surgery.

What are the risks?

Short-term risks include infection, leakage, bleeding and blood clots. In the long term, a person may experience a variety of problems, depending on the procedure.

Although gastric banding surgery is generally considered safer than other weight loss procedures, the band may slip out of place or erode.

With sleeve gastrectomy, the staple lines along the stomach may bleed or leak.

For the gastric bypass, there’s a risk of leaks, hemorrhage, hernia and malnutrition down the road. The biliopancreatic diversion with duodenal switch carries similar complications, except the chances of malnutrition are greater, particularly over the long term.

A person may experience complications any time after having surgery, even years later. With all of the operations, there is a small chance of dying from complications.

A recent study showed that bariatric surgery holds promise for people with diabetes. What's the scoop?

"That’s the most exciting part of all this," says Dr. Shikora. "All of the surgeries—particularly the bypass, sleeve and biliopancreatic diversion with duodenal switch—can cause dramatic improvements in diabetes. And for many patients, the diabetes goes into complete remission—it disappears."

"Weight loss is one reason. With certain operations such as gastric bypass and perhaps the sleeve and the duodenal switch, it's also hormonal. We may be doing something that dramatically improves the function of the pancreas."

"Someone who is obese (BMI over 35) and has diabetes may want to consider having weight loss surgery. It may be best for a person with recent onset because the pancreas is less damaged."

Can surgery improve other medical conditions?

A study of 22,000 patients showed that bariatric surgery improved not only diabetes in a majority of patients, but also high blood pressure, sleep apnea and high cholesterol.

There’s some evidence that weight loss surgery reduces the chances of dying from obesity-related conditions, particularly from diabetes, heart disease and cancer.

Will some people fail to lose weight following surgery—or regain the weight?

"Yes," says Dr. Shikora. "About one in four surgical patients fails because they stop exercising or eating an appropriate diet—basically falling back to old habits. Patients really need to motivate themselves to do what it takes to avoid falling into a bad trap. An operation isn’t the end all for weight loss success; it’s only a beginning; weight loss surgery isn’t a cure, it’s a tool."

On the positive side, one study showed that patients can maintain a weight loss of 50 to 60 percent of their excess weight as long as 10 to 14 years after surgery.

Does insurance typically cover a procedure?

"Some insurance companies cover it, but not all," notes Dr. Shikora. "Yet research is showing that insurance companies get a return on their investment in two to four years, when the cost of other weight loss treatments exceeds the cost of surgery."

Publication Review By: the Editorial Staff at

Published: 01 May 2008

Last Modified: 19 Mar 2015