Obesity is a chronic disorder that can lead to other health problems such as diabetes, high blood pressure, and obstructive sleep apnea. Because obesity can affect many organs, it may be difficult to treat. When other medically supervised methods of weight loss have failed, weight-loss surgery can be an effective way to lose weight and maintain that weight loss.
To be considered for weight-loss surgery, you must meet the following qualifications:
- A body mass index (BMI) of 40 or higher (20 to 25 is considered normal). BMI is a calculated by dividing your weight in kilograms by height in meters squared. See the BMI chart.
- A body mass index (BMI) between 35 and 40 and have an obesity-related condition such as cardiovascular disease, diabetes mellitus, hypertension or severe sleep apnea.
The UCSF Bariatric Surgery Center has been performing surgical weight-loss procedures since 1996. We offer two weight-loss procedures. Both are considered "restrictive," meaning the procedure limits the amount of food you can consume at one time.
During your initial visit to the Bariatric Surgery Center, one of our bariatric surgeons will discuss in detail the different operations, explain the risks and benefits of each, and determine the procedure that's best for you.
When considering weight-loss surgery, it is important to understand that success in maintaining weight loss depends on your commitment to making major diet and lifestyle changes. Surgery is a powerful tool meant to assist in weight loss. Your participation at home and through our bariatric program is important in achieving your weight loss goals, and in maintaining weight loss so you can be successful many years after surgery.
Weight-Loss Procedures at UCSF
Roux-en-Y Gastric Bypass
Gastric bypass is the current "gold standard" procedure for weight-loss surgery, according to the American Society for Bariatric Surgery and the National Institutes of Health. This procedure bypasses most of the stomach and the first part of the small intestine.
A small stomach pouch is created using a surgical stapler. The remainder of the stomach is not removed, but is stapled shut. The pouch restricts food intake so you're only able to eat small amounts of food at one time. The small intestine is divided and one end is raised and attached to the stomach pouch in a procedure called a gastrojejunostomy. The other end of the small intestine, still connected to the stomach remnant, is reconnected to another portion of the intestinal tract in a procedure called a jejunojejunostomy.
Advantages of gastric bypass include:
- Average weight loss is 70 to 80 percent of your excess body weight.
- Average weight loss is greater than the average achieved by two other weight-loss procedures, sleeve gastrectomy and gastric band surgery.
- Studies show that gastric bypass surgery alters the metabolism of carbohydrates and increases insulin sensitivity, often eliminating the need for diabetes medications.
- Medical conditions related to obesity — such as acid reflux, high cholesterol and high blood pressure, and sleep apnea — are improved or eliminated after surgery.
Disadvantages of gastric bypass include:
- Absorption of iron and calcium is decreased because the duodenum, or first part of the small intestine, is bypassed. Deficiencies of these minerals can lead to anemia and bone disease so you must take vitamins and other supplements.
- Vitamin B12 supplements must be taken to prevent a deficiency.
- A condition known as "dumping syndrome" can occur after eating too quickly or after eating foods high in refined sugars or carbohydrates or high in fat. Symptoms include nausea, sweating, light headedness, flushing and fast heart rate.
- In some cases, the procedure's effectiveness may lessen if the stomach pouch is stretched or if it is initially left larger than 15 to 30 cubic centimeters.
- The bypassed portion of the stomach, duodenum and segments of the small intestine cannot be easily visualized using X-ray or endoscopy if problems such as ulcers, bleeding or cancer occur.
This operation involves only your stomach. A small sleeve, or narrow pouch, is created using a surgical stapler to separate the stomach. After the sleeve is created, the rest of the stomach — about two-thirds of the stomach — is removed. The sleeve creates a feeling of being full faster and decreases appetite. Only small amounts of food can pass through the sleeve at one time.
Advantages of sleeve gastrectomy include:
- No foreign body implanted.
- No rerouting of the intestinal tract.
- Average weight loss is greater than gastric band, but slightly less than gastric bypass.
Disadvantages of sleeve gastrectomy include:
- Less long-term data available on the outcomes of sleeve gastrectomy.
- Risk of leaking at the staple line of the stomach.
Laparoscopic or Minimally Invasive Surgery
Laparoscopic surgery, also called minimally invasive surgery, involves inserting a tiny video camera and surgical instruments into the abdomen through several small incisions. The surgeon can then view images from the camera during the surgery. In traditional open surgery, the surgeon makes one long incision to open the abdomen.
The American Society for Bariatric Surgery recommends that laparoscopic weight-loss surgery be performed only by surgeons experienced in both laparoscopic and open bariatric procedures. At the UCSF Bariatric Surgery Center, our experts are trained in the advanced techniques required to perform laparoscopic procedures.
Laparoscopic surgery is considered minimally invasive because it replaces the need for a large incision. Studies show that laparoscopic weight-loss surgery has several benefits for patients when compared to open surgery, including:
- Less pain after surgery
- Fewer wound complications, such as infection or hernia
- Faster recovery and return to normal activities
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.
Clinics we work with
Bariatric Surgery Center
400 Parnassus Ave., Second Floor
San Francisco, CA 94143
Bariatric Surgery Support Group
This group is open to patients who have undergone weight-loss surgery as well as those who are considering the procedure. Friends and family are welcome.
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Body Mass Index Chart
Body mass index (BMI) is a number based on both your height and weight and can help determine the degree to which a person is overweight. Learn more.
Dietary Guidelines After Bariatric Surgery
It is very important to follow the recommended dietary guidelines after undergoing bariatric surgery. Find general guidelines for fluids, protein and more here.
Bariatric Surgery Requirements and Evaluation
To be eligible for bariatric surgery, you must weigh less than 450 lbs. because that's the max weight that hospital X-ray equipment can accommodate. Learn more.
Life After Bariatric Surgery
The UCSF Bariatric Surgery Center offers comprehensive follow-up care, including a support group, dietitian and education to help you achieve long-term success.
Recovering from Bariatric Surgery
Patients spend an average of two to five days in the hospital following bariatric surgery, or longer if complications develop. Learn more here.
Surgical Weight Loss Procedures for Kidney Transplant Patients
In the case of patients waiting for a kidney transplant, losing weight also can improve their chances of being a transplant candidate. Learn more here.