Weight-loss (bariatric) surgery is a lifesaving and life-changing treatment for severely obese patients who have not had success with traditional, medically supervised weight-loss strategies such as diet modification, exercise, and/or medication. It works by physically restricting the amount of food patients can eat and/or by interrupting the digestive process. It does not remove fatty tissue.
Severe obesity, commonly defined as weight that is at least 100 pounds more than the ideal for age and height, is the second-leading cause of preventable death in the United States. Some 18 million people in the United States suffer from it. With this condition sharply on the rise in the United States, the number of weight-loss procedures has also jumped, from 16,000 in the early 1990s to 180,000 in 2005, according to the American Society for Bariatric Surgery.
This module explains when bariatric surgery might be appropriate, what is involved in the procedure, and what to expect immediately after the surgery and in the long term.
Bariatric surgery induces weight loss by physically restricting the amount of food patients can eat and/or by interrupting the digestive process. It does not work by removing fatty tissue from the body.
Bariatric procedures fall into three categories:
• Restrictive surgeries, such as the Lap-Band® procedure, the vertical banded gastroplasty ("stomach stapling"), and the sleeve gastrectomy, physically limit the amount of food a patient can consume by reducing the size of the stomach or the amount it can expand.
• Combined procedures, including Roux-en-Y gastric bypass, do the same but also surgically reroute the digestive tract so that food actually bypasses most of the stomach. Combined procedures make up 80 to 85 percent of all bariatric surgeries performed in the United States.
• Malabsorptive procedures, such as biliopancreatic diversion bypass, do not affect food intake but instead limit the absorption of calories and nutrients from food by creating a bypass around a significant length of intestine.
For very ill obese patients, for whom the restrictive or combined surgeries might be too risky, the procedures are sometimes broken down into two smaller operations.
Some bariatric procedures are performed with traditional "open surgery," necessitating a large abdominal incision, while others can be performed laparoscopically, meaning that they are conducted by making small incisions in the abdomen and inserting tiny instruments through those incisions.
During laparoscopic surgery, a telescope and camera project the image of the patient's organs and the surgical instruments onto a video monitor. Because of the minimally invasive nature of laparoscopic surgery, time in the hospital, postoperative pain, and infection risks are markedly reduced in comparison to open surgery but not entirely eliminated.
In some cases, bariatric surgery that may typically be performed laparoscopically is inadvisable because of a patient's weight, body shape, or previous surgeries. In those instances, open surgery can usually be performed instead.
To determine which, if any, procedure may be appropriate, bariatric surgeons must weigh the risks versus the benefits for each patient. The patients as well as their doctors should also consider which procedures the surgeons have the most experience performing.
This section has more information on:
Approved by the Food and Drug Administration in 2001, the Lap-Band® procedure involves implanting an adjustable band that contains saline solution around the stomach to reduce its size. This surgery is reversible, causing no permanent change in patient anatomy. As the "Lap" part of the name suggests, it is usually performed laparoscopically (through a small incision). In recent years, the Realize Band®, another form of adjustable gastric band, has also been FDA approved for use in the United States.
Because the band restricts the amount of food that can be consumed, patients feel full sooner than they did before the procedure. Neither the production of digestive enzymes nor the body's ability to absorb vitamins and nutrients is affected by this surgery.
In accordance with the patient's weight loss and wellness goals, the Lap-Band can be loosened or tightened with a needle that increases or decreases the amount of saline solution in the band through a "port" placed underneath the skin during the surgery. These adjustments can be made during regular outpatient physician visits. About a half-dozen adjustments are usually required during the one to two years after surgery and only once or twice a year after that.
The Lap-Band procedure is safe for the majority of patients, but, as with any surgery, there are risks. Most of them are not life-threatening.
While more than 300,000 Lap-Band procedures have been performed worldwide, the resulting weight loss is usually less significant for these patients than for those who opt for combined surgeries (such as the Roux-en-Y), which both restrict stomach size and disrupt the digestive process.
The band can be removed—typically laparoscopically—although experts often recommend leaving it implanted indefinitely in patients who are benefiting from it. Because this procedure is relatively new, data about the effects of long-term implantation are not yet available.
Bariatric surgeons often recommend the Lap-Band procedure for patients who need to lose 50 pounds or less, who do not want a permanent change in their digestive system via surgery, or who are at very high risk from open surgery.
It is important that patients who opt for Lap-Band surgery commit themselves to meaningful long-term weight loss and the lifestyle changes necessary to achieve that.
Commonly known as stomach stapling, vertical banded gastroplasty is similar to the Lap-Band procedure in that the size of the stomach is physically reduced without interrupting a patient's digestive process. This less reversible procedure, however, utilizes both a band and surgical staples—and the band is not adjustable.
Once one of the most popular bariatric procedures, VBG is no longer commonly performed or recommended by most bariatric surgeons in the United States, and it has been effectively replaced by adjustable gastric banding procedures. One reason for this change is that, according to the National Institutes of Health, between 15 and 20 percent of VBG patients must undergo a second surgery to repair a complication from the initial procedure.
In addition, stomach-reduction procedures such as VBG typically result in less significant weight loss than bariatric surgeries that both restrict stomach size and interrupt the digestive process.
A restrictive stapling procedure, the sleeve gastrectomy removes a large portion of the stomach and transforms the shape of the remaining stomach from saclike to narrow and tubular. The surgery often can be performed laparoscopically.
A sleeve gastrectomy is frequently advised for patients deemed to be high risk for other types of bariatric surgery or those who are otherwise unable to undergo a laparoscopic procedure for weight loss.
The sleeve gastrectomy is also gaining popularity as a part of a "staged" approach to reducing risk: Very ill obese patients, for whom other restrictive or combined surgeries might be too dangerous, sometimes undergo a sleeve gastrectomy first and then become fit candidates for further weight-loss surgery.
Considered the gold standard in weight-loss surgery throughout the medical community, Roux-en-Y gastric bypass surgery has been the most successful surgical procedure for total weight loss and long-term maintenance with the fewest metabolic complications.
This combined bariatric procedure restricts the amount of food patients can eat and also alters the digestive process by which calories are absorbed in the intestine. Approximately 170,000 U.S. patients underwent Roux-en-Y gastric bypass surgery in 2005, according to the American Society for Bariatric Surgery.
During the procedure—which is often performed laparoscopically—surgeons use approximately 5 percent of a patient's stomach to create a gastric pouch at the bottom of the esophagus. The pouch is connected directly to the middle part of the small intestine, bypassing not only the rest of the stomach but also the upper portion of the intestine, where some of the food's calories are normally absorbed.
The result is a "new" stomach about the size of an egg that continues producing the enzymes and juices necessary for digestion.
Although patients still absorb most of the vitamins and nutrients from the foods they eat—only iron, calcium, and vitamin B12 typically require post-surgical supplementation—they consume considerably less and typically must eat more slowly, which causes their brains to receive signals of fullness from the gastric pouch sooner than they did prior to the surgery.
The Roux-en-Y gastric bypass is safe for most patients, but as with any surgery, there is always a risk of complications. Most of them are not life-threatening.
Theoretically, the bypass can be surgically reversed and normal digestive functions restored; however, such reversals are ill-advised because of their high risk.
The Roux-en-Y bypass is typically best for patients who need to lose more than 50 pounds and/or those with serious health problems, such as diabetes, that are known to respond rapidly to gastric bypass surgery.
The biliopancreatic diversion is a complicated combined procedure that makes up fewer than 3 percent of all bariatric surgeries performed in the United States.
BPD/DS surgery removes the lower section of the stomach, leaving a fairly large stomach pouch that is connected to the bottom part of the small intestine, called the distal ileum.
The BPD/DS surgery induces weight loss regardless of the patient's behavior, but the irreversible procedure puts people at a higher risk of serious long-term nutritional deficiencies than other types of bariatric surgeries.
This procedure typically is best for patients who need to lose extreme amounts of weight and are committed to long-term follow-up.
Countless people would like to lose weight, but only those whose high weight poses a threat to their lives—the severely or "morbidly" obese—are considered viable candidates for undergoing bariatric surgery. Commonly defined as weight that is at least 100 pounds more than the ideal body weight for a person's height and age, severe obesity is typically diagnosed based on a patient's body mass index, or ratio of fat to lean body mass. In general, people with a BMI greater than 35 are diagnosed as severely obese.
To qualify for bariatric surgery, patients must typically:
Patients who are not candidates for any type of bariatric surgery include those:
Despite the national push in recent years to inform the public that severe obesity is a serious chronic disease and to change a perception that obese people are simply lazy and undisciplined, many people, including many healthcare professionals, still have a strong bias against the obese. A bias against bariatric surgery also exists, with some people considering these procedures a crutch for people unwilling to work to lose weight.
For the severely obese, however, bariatric surgery has been shown to be more effective than nonsurgical treatments at achieving and maintaining the weight loss necessary for their health.
Patients who believe they may be candidates for bariatric surgery should speak with their physicians as well as their insurance providers.
This section has more information on:
According to the Centers for Disease Control and Prevention, severe obesity—also known as morbid obesity—is the second-leading cause of preventable death in the United States, with cigarette smoking being the first. Women are affected at about twice the rate of men.
Severe obesity is a chronic, life-threatening disease that leads to medical conditions that cost approximately $100 billion in healthcare annually in the United States. Some 300,000 preventable deaths are attributed to the serious medical conditions brought on by severe obesity each year.
This chronic disease often leads to or coexists with serious conditions such as:
Severely obese people are at increased risk for a number of cancers and may suffer from incontinence, gastric reflux disease, chronic pain, and impotence.
The severely obese also suffer from depression at nearly 10 times the rate of people of healthy weight. The reason behind this phenomenon is believed to be twofold:
• Social causes. People who are severely obese often have limited opportunities for social and recreational activity, and they face social isolation, discrimination, ridicule, and restricted use of public conveniences.
• Genetic causes. Scientists have identified a gene, known as the ob gene, that may predispose people to both obesity and depression.
While the cause of severe obesity has yet to be identified, it is probably the result of both genetic and environmental factors.
Most reputable bariatric surgery programs have a counseling component, because people considering weight-loss surgery must fully understand the significant life changes that will follow.
Presurgical counseling should include a comprehensive evaluation of a person's physical and mental health, as well as his or her dietary and activity habits, overall lifestyle, and post-surgical wellness goals.
Counseling may be conducted by a multidisciplinary team that includes physicians and other medical staff, nutritionists, exercise physiologists, and mental-health professionals.
Because bariatric surgery is a relatively new surgical specialty, there are not yet enough medical data to predict with certainty which patients will have better outcomes with which procedures.
Bariatric surgery can improve the health and lengthen the life span of people who are severely obese. Those who have weight-loss surgery are less likely to die from heart disease, diabetes, and cancer seven to 10 years following the procedure than similarly heavy people who don't have the operation, according to two studies reported in 2007 in the New England Journal of Medicine.
Other studies show that for the severely obese, bariatric surgery is more effective at achieving and maintaining weight loss than nonsurgical treatments.
As weight loss occurs, bariatric surgery patients may see improvements in a number of serious medical conditions. For example:
Because combined procedures typically result in more weight loss than restrictive surgeries, patients who undergo Roux-en-Y and biliopancreatic diversion bypass surgeries tend to see a greater improvement in their health—and see it more quickly—than those who opt for the Lap-Band procedure.
Overall, the health benefits of bariatric surgery far outweigh the risks for most severely obese patients—and many report feeling as though they've been given a second chance at leading healthy lives.
Average weight lost
The amount of weight a patient loses after bariatric surgery depends upon a number of factors, including the type of procedure performed, the patient's health and weight before surgery (heavier patients tend to lose more), and how faithfully the patient follows physician-recommended diet and exercise plans. The following are weight-loss averages for the various types of bariatric surgery:
Roux-en-Y gastric bypass. Within about 14 months, patients who undergo the Roux-en-Y gastric bypass lose an average of 60 percent of their excess body weight—or approximately 140 pounds.
Adjustable gastric banding procedure. Weight loss following the Lap-Band procedure averages 50 percent of patients' excess weight—or about 80 pounds—and typically occurs over two to three years.
Vertical banded gastroplasty. Patients who undergo VBG lose an average of 50 percent of their excess body weight. Data suggest, however, that over the long term, only a fourth of the patients keep that much weight off.
Sleeve gastrectomy. The sleeve gastrectomy is a relatively new procedure, and data are limited. Early studies indicate that average weight loss falls between the losses seen with the Lap-Band procedure and the Roux-en-Y gastric bypass.
Biliopancreatic diversion with duodenal switch. Patients who undergo BPD/DS surgery lose an average of 70 to 80 percent of their excess body weight within the first two years of the procedure.
Individual patients may lose more or less weight than indicated by these national averages. Maintaining the weight loss depends largely on a patient's post-surgical diet and level of physical activity.
Many studies have documented long-term medical follow-up to be very important in achieving maximal weight loss after bariatric surgery. Patients are sometimes encouraged to continue with counseling for eating disorders for at least two years. Postoperative counseling serves not only to support patients as they work to significantly alter their dietary and activity habits but also to guide them through the physical, emotional, and social changes that inevitably result from dramatic weight loss.
Most bariatric surgery patients will not experience any complications related to their procedures. However, a small degree of risk, including death, is inherent to all types of surgery and use of anesthesia. Because restrictive procedures are less complicated than combined procedures, they are generally safer and result in fewer complications.
The Journal of the American Medical Association reported in October 2005 that the in-hospital mortality rate among bariatric surgery patients was 0.1 to 0.2 percent. At 30 days post-surgery, mortality estimates ranged from 0.33 to 1.9 percent. A scoring system recently developed by a Duke University bariatric surgeon appears to accurately predict which patients considering bariatric surgery are most likely to die from the procedure. The system adds up the following five risk factors; patients with four of them are six times as likely to die as those with only one:
Roux-en-Y gastric bypass complications
Roux-en-Y gastric bypass surgery is a major operation, associated with an overall complication rate of about 20 percent—meaning that approximately 1 in 5 patients will experience some type of postoperative complication. Most complications are minor, including urinary tract infection, muscle spasms of the abdominal wall, and nausea, but more significant complications can happen.
It is highly unlikely for the pouch to burst because of overeating.
Although serious complications are usually treated successfully, they can lead to permanent disability or even death. The mortality rate for gastric bypass surgery is 0.5 percent.
Adjustable gastric banding procedure complications
The most frequent risks associated with the band procedures are:
Several studies have shown that people who experience significant weight loss can develop gallstones. Although many people with gallstones suffer no adverse effects and may not even know they have them, some surgeons opt to remove the gallbladder during gastric bypass surgery to eliminate this possible complication. Because removal of the gallbladder during a gastric bypass procedure can be complicated, any potential benefits may be outweighed by risks. Patients who have or are prone to having problematic gallstones should raise this issue with their physician before deciding upon bariatric surgery. These patients may benefit from gallbladder removal or gallstone-dissolving medications.
People who undergo bariatric surgery have a higher than normal risk of suicide, according to a 2007 report in the Archives of Surgery. Most of the suicides reported occurred at least a year after surgery. The cause may be an underlying depression that existed before the operation, but the report shows that it's important for patients to receive counseling after the surgery as well as before.
Regardless of the type of bariatric surgery they have, patients are typically encouraged to get out of bed the next day, walk often, and use a spirometer (to promote lung function) until their physicians say they can stop.
Following hospital discharge, it is critical that all patients adhere to their physician-recommended dietary restrictions without exception. These specialized diets are designed not only to promote healing of the digestive tract but also to prevent additional injury to organs already traumatized by surgery.
Here's what patients can expect after undergoing the most commonly performed bariatric surgeries:
Roux-en-Y gastric bypass
Most patients awaken from Roux-en-Y gastric bypass surgery to find one or two tubes coming from their bodies, in addition to an intravenous catheter. One of those tubes, a Foley catheter, empties urine from the bladder into a bag, eliminating the need to get out of bed to urinate. The catheter is typically removed the day after surgery.
The other tube, which may be inserted into the patient's right side, drains any blood or fluid that accumulates near the stomach. This tube is removed before patients are discharged from the hospital, typically two to three days after undergoing Roux-en-Y gastric bypass if there have been no surgery-related complications.
Patients may be asked to drink something called contrast liquid the day after their surgery. Contrast liquid enables radiologists to see any leaks in the intestinal sutures. Once it has been determined that all sutures are secure, patients typically are advised to begin a liquid diet.
When patients can easily tolerate water, they normally proceed to drinking approximately 2 ounces of "full liquids" every waking hour. Full liquids are fluids that do not contain solids or very thick material.
Patients often are instructed to continue on a diet of full liquids for about three weeks after they leave the hospital. Many are advised to drink small amounts of liquid protein products at predetermined times throughout the day, as well as to consume about 2 ounces of any liquid several times each waking hour. This regimen not only helps the digestive tract return to normal function but also prevents dehydration.
Gastric bypass patients typically are required to see their physician about three weeks after their procedure. This follow-up visit allows the weight-loss team to evaluate patient progress and well-being, as well as to provide guidance for a safe transition to solid foods.
Adjustable gastric band procedures
Patients who undergo band surgery usually awaken to discover only one tube inserted in their bodies: an intravenous catheter in one hand.
These patients are normally asked to swallow a small amount of liquid when the effects of anesthesia have completely subsided. After the liquid passes satisfactorily, patients often are instructed to consume only liquids for about two weeks at home and then to gradually add easily chewable foods as tolerated.
Depending on how well patients tolerate the banding procedure, as well as the time of day the surgery is performed, patients may be able to safely go home the same day. Nearly all patients are fit for discharge by the morning following the procedure.
Most patients have virtually no post-discharge dietary restrictions, except to avoid hard-to-digest foods and overeating. The device is usually tightened for the first time approximately six weeks after surgery—and about six times during the first post-surgical year or two. After that, adjustments are typically made only once or twice annually.
Resuming physical activity and going back to work
Physicians strongly encourage patients to walk as soon as possible following all types of bariatric surgery and to increase their level of activity a bit every day during their recovery. This both helps the body heal and reinforces the active lifestyle that all people need to stay healthy.
By the time patients are discharged from the hospital, they should be able to walk short distances without difficulty. By the end of the first month, most patients should be walking 1 to 2 miles every day. Some patients join their local YMCA, mall-walking group, or fitness club, while others enroll in sessions at physical therapy or rehabilitation facilities. Water aerobics is an excellent form of exercise, particularly for patients with degenerative joint problems.
Most gastric bypass patients are well enough to return to work between three and six weeks after surgery. Lap-Band, sleeve gastrectomy, and VBG patients often can return to work within about a week of their procedures.
Skin and hair
As a result of their dramatic weight loss, many bariatric surgery patients develop some loose, flabby skin on their arms, breasts, ankles, legs, face, and neck over time. While some people may wish to undergo plastic surgery to correct this condition, they should be aware of the following:
• Many insurance carriers deem such procedures cosmetic and do not cover the expense. Patients should speak with their insurance agent before pursuing any type of plastic surgery.
• Most physicians will not consider plastic surgery for a bariatric surgery patient until at least one year after the procedure—and only when the patient's weight has stabilized. Although it has not been scientifically proved, it appears that the more patients exercise after undergoing bariatric surgery, the less likely they are to have loose, excess skin.
• Minor hair loss can sometimes result from a rapid and/or significant decrease in weight, as occurs following bariatric surgery.
Patients who do lose some hair usually do so between two and four months after their procedure. Low intake of protein and zinc are often to blame, and the vast majority of patients regrow most, if not all, of the lost hair once their weight stabilizes and after they have resumed regular consumption of the recommended daily amounts of protein, vitamins, and minerals.
Patients are frequently encouraged—and sometimes required—to participate in counseling sessions after they have undergone bariatric surgery. Postoperative counseling serves not only to support patients as they work to significantly alter their dietary and activity habits but also to guide them through the physical, emotional, and social changes that inevitably result from dramatic weight loss.
Patients who undergo bariatric surgery usually must completely transform the diet and activity habits they have spent a lifetime developing. Because this change can be difficult for many people, those interested in a surgical weight-loss procedure should carefully consider the postoperative and exercise recommendations.
Patients who undergo the two most commonly performed bariatric surgeries must adhere to the following long-term dietary restrictions:
Roux-en-Y gastric bypass
Postoperative patients will always eat more frequently than they did prior to surgery. The number of small "meals" consumed daily will vary among patients, from three to eight. Patients must not only adjust the frequency of meals and quantity of foods they eat but also learn to eat slowly and chew thoroughly. In general, patients should eat only when they are hungry and stop eating when they feel full. In addition:
In addition, patients typically must take three vitamin supplements for the rest of their lives after undergoing Roux-en-Y gastric bypass surgery:
For the first three post-surgery weeks, the supplements should be chewable; after that, a pill form is preferred.
Adjustable gastric banding procedure
Following discharge from the hospital, most patients who have undergone a banding procedure are instructed to gradually add soft, easily chewable foods as they are able to tolerate them. While some physicians may recommend vitamin supplements for certain patients, there are usually no restrictions on dietary intake except to avoid hard-to-digest foods and overeating.
According to the National Institutes of Health, the cost of bariatric surgery varies widely, ranging from about $12,000 to $35,000 or more, depending upon factors such as:
The number of bariatric procedures performed in the United States has leveled out since 2005, after rising sharply from the early 1990s. This is possibly because of insurers' increasingly stringent qualifications for surgery. It is important for patients to speak with their health insurance providers before taking steps to undergo bariatric surgery, as not all insurers cover these procedures, particularly the Lap-Band® surgery.
Questions patients might ask include:
Last reviewed on 1/28/10
U.S. News's featured content providers were not involved in the selection of advertisers appearing on this website, and the placement of such advertisement in no way implies that these content providers endorse the products and services advertised. Disclaimer and a note about your health.