Exercise and diet alone often fail to effectively treat people with extreme and excessive obesity. Bariatric surgery is an operation that is performed to help such individuals lose weight. Evidence suggests that bariatric surgery may lower death rates for patients with severe obesity, especially when coupled with healthy eating and lifestyle changes after surgery.
The basic principle of bariatric surgery is to restrict food intake and decrease the absorption of food in the stomach and intestines.The digestion process begins in the mouth where food is chewed and mixed with saliva and other enzyme-containing secretions. The food then reaches the stomach where it is mixed with digestive juices and broken down so that nutrients and calories can be absorbed. Digestion then becomes faster as food moves into the duodenum (first part of the small intestine) where it is mixed with bile and pancreatic juice.
Bariatric surgery is designed to alter or interrupt this digestion process so that food is not broken down and absorbed in the usual way. A reduction in the amount of nutrients and calories absorbed enables patients to lose weight and decrease their risk for obesity-related health risks or disorders.
Body Mass Index (BMI)
Body mass index (BMI), a measure of height in relation to weight, is used to define levels of obesity and help determine whether bariatric intervention is required. Clinically severe obesity describes a BMI of over 40 kg/m2 or a BMI of over 35 kg/m2 in combination with severe health problems.
Health problems associated with obesity include type 2 diabetes, arthritis, heart disease, and severe obstructive sleep apnea. The Food and Drug Administration (FDA) approves the use of adjustable gastric banding for patients with a BMI of 30 kg/m2 or more who also have at least one of these conditions.
There are various types of bariatric surgeries that can be performed. Surgery may be performed using an “open” approach, which involves cutting open the abdomen or by means of laparoscopy, during which surgical instruments are guided into the abdomen through small half-inch incisions. Today, most bariatric surgery is laparoscopic because compared with open surgery, it requires less extensive cuts, causes relatively minimal tissue damage, leads to fewer post-operative complications and allows for earlier hospital discharge.
There are three types of operations that are offered:
Each of the surgery types has advantages and disadvantages and various patient factors affect which procedure is chosen including BMI, eating habits, health problems related to obesity, and number of previous stomach surgeries. The patient and provider should discuss the most suitable option by considering the benefits and risks of each type of surgery.
Surgical and post-operative risks
People who have had bariatric surgery need to adhere to a rigorous and lifelong diet and exercise plan to prevent complications and to avoid putting on weight after surgery. In addition, patients may develop excess loose and folded skin that requires further surgery to remove and tighten.
The preoperative evaluation is similar for all bariatric procedures. The components include determining a patient’s indications for surgery, identifying issues which may interfere with the success of the surgery, and assessing and treating co morbid diseases. Typical assessment includes psychological testing, nutrition evaluation, and medical assessment.
Patients referred for bariatric surgery are more likely than the overall population to have psychopathology such as somatization, social phobia, obsessive-compulsive disorder, substance abuse/dependency, binge-eating disorder, post-traumatic stress disorder, generalized anxiety disorder, and depression. Patients with psychiatric disorders may have a suboptimal outcome after bariatric surgery. It is not certain which psychosocial factors predict success following bariatric surgery, yet many programs exclude patients who are illicit drug abusers, have active uncontrolled schizophrenia or psychosis, severe mental retardation, heavy alcohol use, or lack of knowledge about the surgery.
We offer nutrition consultations for people undergoing gastric surgery and post-op consultations. Consultations include one-on-one counselling with a registered dietician. The nutrition consultant is an integral part of multidisciplinary bariatric care. He/she is charged with nutritional assessment, diet education regarding postoperative eating behaviours, and preoperative weight loss efforts.
Medical assessment prior to bariatric surgery is similar to abdominal operations of the same magnitude. Thorough history and physical examination with systematic review is used to identify issues that may complicate the surgery. Routine laboratory evaluation typically includes complete blood count, metabolic profile, coagulation profile, lipid profile, thyroid function tests, and ferritin. Vitamin B12, and fat-soluble vitamin levels may be evaluated if considering a malabsorptive procedure. Cardiovascular evaluation includes electrocardiogram and possible stress test to identify occult coronary artery disease. Respiratory evaluation may include chest X-ray and pulmonary function tests. Sleep apnea may be diagnosed by sleep study if any was suspected. Upper endoscopy may be used if suspicion of gastric pathology exists. If H. pylori infection is present, preoperative therapy is advised. The liver may be assessed by hepatic profile and ultrasound. Ultrasound may be used to detect gallstones as well, allowing the surgeon to decide on concomitant cholecystectomy.
The goal is to limit the amount of calories you consume, while providing balanced meals that help prevent nutrient deficiencies and preserve muscle tissue. It is very important to follow the nutritional guidelines to prevent weight gain, deficiencies and complications.
After the surgery, you will have to go on a liquid diet for the first two weeks, gradually changing to pureed diet after week 2, and finally moving on to eating solids after week 4. Protein supplements and different vitamins and minerals might be necessary to help with the healing process.
The general guidelines that you need to follow are:
The success of the surgery is very much dependent on changing your lifestyle and eating habits. With time, the new habits will become easier and the results that you get from the surgery and the new lifestyle are very rewarding and the positive effects on your health and your body are very worthwhile.
If you want to compare your weight status to others, BMI is a great method of analysis.
To be a candidate for obesity surgery, you must have the following criteria