Nutrition Management After Gastric Bypass Surgery
- Judy Dowd, MA, RD, LDN
Gastric bypass surgery is a highly effective weight-loss treatment for morbid obesity. Surgery is a tool by which individual patients learn to control their calorie intake without feeling excessive hunger. As a result, significant weight can be reduced to improve symptoms of many chronic illnesses, such as coronary heart disease and diabetes. The fact that most insurers, including Medicare, pay for the procedure testifies to its effectiveness. People with diabetes and heart disease are eligible for reimbursement at slightly lower body weights, although they must still be obese (Table 1).
The process, both before and after surgery, is fraught with pitfalls, which put a great deal of responsibility on both the surgical team and the patient. The team should consist of one or more certified bariatric surgeons, experienced dietitians, nurses, and psychologists. Extensive preoperative screening is important (Table 1).
As much as 60–70% of excess weight is lost in the 1–2 years following surgery1 as a result of four postoperative phenomena (Table 2). Fewer calories are consumed because of patients' smaller stomach capacity. Also, patients experience a diminished appetite, perhaps because of a reduced production of appetite-stimulating hormones, such as ghrelin. Binge-like behavior tends to be extinguished postoperatively because it results in immediate negative consequences in the form of pain and vomiting. Malabsorption of calories occurs as a result of the bypassed small intestine. The bypass also induces the dumping syndrome in those patients who consume a food or beverage containing a concentration of sugar. This syndrome produces symptoms similar to a hypoglycemic reaction. Because of this noxious effect, the dumping syndrome works well to dissuade patients from eating sweets. And finally, increased physical activity, which enhances weight loss and helps prevent weight regain, becomes increasingly possible as …