Surgery for Obesity: What is it?
Weight loss surgery, or Bariatric surgery, is a treatment option suitable for some people with severe obesity. It creates a change in the anatomy of a person’s digestive system to limit the amount of food he or she can eat and digest.
Who are the Candidates?
The National Institutes of Health established the following criteria for patients:
- Body mass index (BMI) is 40 kg/m2 or higher, or 35 to 39.9 kg/m2 with serious weight-related health problems (e.g. diabetes or heart disease);
- Have tried other non-surgical methods of weight loss without success;
- Well informed about potential risks and possible changes associated with surgery;
- Willing to make a lifelong behavioral commitment
Even if all these conditions are met, patients must undergo a complete medical, nutritional, and psychiatric evaluation by the medical team before operation to determine eligibility.
What are the Surgical Options?
- Restrictive Surgery promotes weight loss by reducing stomach size to limit the amount of food a patient can eat. Examples are Adjustable Gastric Banding (LapBand) and Vertical Banded Gastroplasty (VBG).
- Combined Restrictive and Malabsorptive Surgery is a combination of both restrictive and malabsorptive techniques, in which some portions of the small intestine that absorb calories and nutrients are bypassed. Roux-en-Y Gastric Bypass (RYGB) and Bibilopancreatic Division (BPD) are the most common examples.
Weighing the Risks and Benefits:
- Risks: Different procedures have different risks, and depending upon individual circumstances, patient may have higher or lower risk than the average. Common risks are wound infection, bleeding, leaks from the stomach or intestine, and/or blood clots. Death after surgery is less than 1%. In addition, patients may be at risk of becoming deficient in iron, folic acid, calcium and vitamin B12. They may also experience protein malnutrition or fat and fat-soluble vitamin malabsorption.
- Benefits: Depending on the surgery type, patients can lose an average of 40% to 70% extra body weight. Patients have experienced marked improvements in diabetes, hypertension, heart health, and a better quality of life after the surgery.
The Role of Dietitians:
Dietitians have strong roles in supporting patients nutritionally to avoid deficiencies and to learn new eating behavior. Patients should consult dietitians who are knowledgeable in obesity surgery so that appropriate dietary modifications can be introduced.
The Take Home Message:
Bariatric surgery is not a magic cure for obesity; it requires significant lifestyle changes with certain levels of risks involved. Individuals who wonder if surgery is an option for them should discuss this option with their doctors. A lifetime medical monitoring by the obesity surgery team is recommended for all patients. Patients should work closely with the medical team, including a registered dietitian, in order to develop an individualized plan for them.
Resources for Consumers:
This fact sheet is intended to help you better understand bariatric surgery and does not take the place of medical advice from the doctor. If you have any questions after reading this fact sheet, please discuss with your doctor, dietitian, or other healthcare professionals.
This fact sheet was created for Dietitians of Canada by Stephanie Kwok, BSc, MSc AHN Candidate (dietetic intern), Mount Saint Vincent University. (link)