Bariatric surgery offers patients the ability to lose weight after all other methods have failed. The procedure limits the size of the stomach to make patients feel full after eating just a small meal. With food intake physically restricted, patients find that they finally lose weight quickly and efficiently.

Bariatric surgery is a term that covers several different procedures that help obese and overweight patients lose weight. Surgical weight loss solutions have been used since the mid-1950s as an option for patients who are unable to achieve lasting, significant weight reduction with diet and exercise, weight-loss medications or other methods. Over the last 30 years, the techniques for these procedures have been improved, reducing the risk of complications.

Who Qualifies for Bariatric Surgery?

Originally, this type of operation was reserved for obese patients (those with a BMI over 40). However, patients with a lower BMI and at least one weight-related health condition may now qualify. This includes patients with high blood pressure, high cholesterol, type 2 diabetes, sleep apnea and joint pain. The type of surgery available varies depending on the patient’s BMI. For example, a duodenal switch might be reserved for those with a BMI over 50. A gastric banding procedure might be available for a patient with a BMI as low as 30. Patients seeking bariatric surgery must have a documented history of medically supervised weight reduction attempts that failed to produce the desired results.

How Does Bariatric Surgery Work?

All bariatric surgeries involve reducing the size of the stomach. This aids weight loss in several ways:

  • Restricting food intake to an ounce or a few ounces of food per meal
  • Limiting hunger cues by reducing the amount of “hunger hormones” released by the stomach
  • Creating a sensation of fullness that occurs faster and lasts longer than before

Gastric bypass and duodenal switch also work by altering the digestive tract. This aids weight loss by limiting the absorption of foods. Weight-loss surgery (WLS) tends to cause very unpleasant side effects when patients deviate from their meal plan. This can help patients practice better self-control in complying with their diet over the long term. As food intake drops, the body begins metabolizing fat, resulting in lost weight. The speed and extent of this weight reduction depends on the type of surgery.

What Are the Different Types of Bariatric Surgery?

There are four major kinds of WLS performed in the United States at this time. These are:

Gastric bypass (Roux-en-Y): A smaller stomach is created by excising most of the stomach and stapling the rest to create a tiny pouch the size of a golf ball. The pouch is attached directly the small intestine, bypassing the rest of the stomach. The separated portion of the stomach and a segment of the small intestine are reattached further down the length of the intestine to aid digestion.

Sleeve gastrectomy: About three-quarters of the stomach is removed, leaving only a narrow tube of stomach that holds just a few ounces of food at a time. The intestines are left intact.

Biliopancreatic diversion with duodenal switch (BPD-DS): The stomach is reduced by about 75 percent. This remaining sleeve of stomach stays attached to the duodenum (the first segment of the small intestine). The next portion of the small intestine is removed and reattached lower on the intestine. The duodenum is reattached to the rest of the intestine to create a new digestive tract. Both sections of intestine join just before the colon to allow digestion of a small amount of food.

Gastric banding: A flexible silicone band is placed around the stomach. It is filled with saline through a length of tubing linked to an access port just under the skin. The saline inflates the band causing it to tighten around the upper portion of the stomach. This restriction permits the consumption of only small quantities of food at each meal.

What Are the Benefits of Bariatric Surgery?

Besides providing a proven method for substantial long-term weight loss, these procedures may also:

  • Reduce reliance on insulin or oral medications for type 2 diabetes
  • Lower “bad” cholesterol
  • Lower blood pressure
  • Minimize joint pain and back pain
  • Increase mobility
  • Reduce sleep apnea symptoms

Some patients experience full reversal of their weight-related diseases after WLS. However, this cannot be guaranteed. Patients must comply with their post-procedure instructions including diet and exercise to enjoy the full benefits of their surgery.

What Are the Risks of Bariatric Surgery?

Weight-loss surgery is a major procedure done under general anesthesia. The mortality rate at 30 days varies from one in 50 to about one in 2,000 patients. The risk of death depends on a variety of risk factors including the type of procedure, the health of the patient and the experience level of the surgeon. Serious complications include bleeding, wound infection and wound separation. Laparoscopic versions of each treatment are less risky than open surgery. Additional complication risks from the surgery include: heart attack, stroke, internal bleeding, pneumonia, blood clots, kidney failure and vein inflammation.

Risks associated with changes to the digestive tract include:

  • Nutritional deficiencies including osteoporosis and anemia from calcium and iron deficiencies
  • Ulcers, blockage, adhesions, leakage, tears, twisting of the bowels (hernia)
  • Device malfunction (with gastric banding)
  • Gallstones, gall bladder infection, kidney stones and inflammation of the stomach lining (gastritis)

Side effects after WLS may include:

  • Dumping (a gastric bypass side effect that causes lightheadedness, stomach cramps, diarrhea, pounding heart, sweating and other symptoms after eating certain foods)
  • Nausea, vomiting, belching, flatulence and diarrhea
  • Food blockage (food getting stuck in the digestive tract – occurs due to eating too quickly or not chewing food thoroughly)
  • Dehydration due to inability to drink large amounts of fluid at one sitting
  • Fatigue, body aches, chills
  • Depression and other mood changes
  • Dry skin, hair loss, irregular menstrual cycle

What Is Life Like After Bariatric Surgery?

The most significant changes are in how, what and when it is okay to eat. Patients start with a liquid diet after surgery and work their way up from soft foods to solid food over a period of weeks or months. The specific foods that are permissible vary based on both the type of surgery and the individual patient’s tolerance. Some patients can eat many different foods after WLS. Others find that certain foods such as dairy or pasta are not an option any longer. Typically, the kinds of foods that cause the most problems are high in fat or simple carbohydrates. Protein and vegetables make up a large part of the post-surgery diet. All meals are much smaller than before surgery. Patients may need to eat more often to ensure adequate intake of nutrients. They must drink water throughout the day between meals (not with meals) to stay hydrated.

Weight loss generally happens very quickly after gastric bypass and duodenal switch. Many patients lose as much as 50 percent of their excess weight within six months. These surgeries may result in a loss of 70 to 80 percent of excess weight overall. Weight reduction is less extensive and occurs more slowly with the gastric sleeve and gastric band procedures. It is common for weight reduction to plateau from time to time before a patient reaches his goal weight. When this happens, it can be helpful to evaluate eating and exercise habits to see if adjustments need to be made. Some weight regain generally happens after any bariatric surgery. Compliance with post-surgery lifestyle instructions may reduce the amount of regain.

As weight loss continues, patients may find that they are dissatisfied with their appearance. Younger patients and those who are less obese tend to have better aesthetic results since their skin may tighten up to match their new body size. Older patients with less skin elasticity and very obese patients are likely to have some sagging of various areas including the arms, abdomen, buttocks and thighs. Patients often choose to have cosmetic surgery to contour these areas.

With the exception of gastric banding, bariatric surgery is unlikely to be readily reversible. This makes it very important for patients to carefully consider all the risks, side effects and lifestyle changes that accompany the procedure.