Manual of Clinical Nutrition Management B- 17 Copyright © 2013 Compass Group, Inc.
NUTRITION MANAGEMENT IN BARIATRIC SURGERY
Discussion
Severe obesity (also referred to as morbid obesity) is a chronic condition that is difficult to treat with
traditional weight loss methods (1-4). Surgery to promote weight loss by restricting food intake or interrupting
the normal digestive process is recognized by the medical community as an effective medical option for
severely obese people when other weight management approaches have proved unsuccessful (1-4). Bariatric
surgery promotes weight loss by introducing anatomical alterations that reduce the size of the gastric
reservoir or cause malabsorption (1-3). The role of nutrition is paramount in bariatric surgery. Patients who
undergo bariatric surgery require intensive nutrition intervention, routine nutrition evaluation, and close
nutrition monitoring to produce optimal nutrition care and weight loss outcomes (1,4). Another critical
element is the patients themselves who must be committed to make permanent and sustainable lifestyle
changes while undergoing medical monitoring for life.
The American Association of Clinical Endocrinologists, the Obesity Society, and the American Society for
Metabolic and Bariatric Surgery evaluated presurgical and postsurgical management strategies for obesity
treatment and outlined consensus and evidence-based practice guidelines (1). Bariatric surgery remains an
emerging field. The long-term health implications and nutritional consequences associated with rapid and
substantial weight loss continue to require study to determine the best treatment and management options
(1,4).
Indications for Bariatric Surgery
The following groups of patients meet the criteria for surgical intervention for weight loss if they (and their
parents, in the case of pediatric or adolescent patients) are motivated and able to comply with a lifelong
program (1-3):
adults with a body mass index (BMI) greater than or equal to 40 kg/m^2 with no comorbid conditions or
health risks and acceptable operative risk
adults with a BMI of 35 kg/m^2 or greater with comorbid conditions or health risks such as
cardiopulmonary problems, type 2 diabetes mellitus, or physical limitations
adults whose weight is 100 lb greater than their ideal body weight and who have made multiple
unsuccessful attempts to lose weight with non-surgical methods
children and adolescents who are above the 95th percentile of weight for age and have a severe
comorbidity (1) (These bariatric procedures should be performed in specialized centers.)
The most common types of bariatric surgery are laparoscopic adjustable gastric banding and Roux-en-Y
gastric bypass (1). Although risks and benefits are associated with both approaches, laparoscopic bariatric
procedures are preferred to open procedures if sufficient surgical expertise exists (1). The best choice for any
bariatric procedure should be based on the expertise of the surgeon or institution, patient preferences, and
patient risk stratification (1). Only the laparoscopic adjustable gastric band and Roux-en-Y gastric bypass
should be offered to children and adolescents (1). Restrictive procedures, such as the laparoscopic adjustable
gastric band, may be combined with modified gastric bypass procedures, such as the Roux-en-Y gastric
bypass, to further limit the absorption of energy or nutrients. An investigational procedure known as a first-
stage sleeve gastrectomy may be performed in high-risk patients to induce initial weight loss (25 to 45 kg),
with the possibility of then performing a second-stage Roux-en-Y gastric bypass or a more advanced gastric
bypass surgery (1). Although anatomical changes are made during both types of surgeries, the patient who
does not strictly adhere to the volume restrictions and types of food allowed can negatively affect the
outcomes of the procedure (1). Consuming too much food can stretch the surgical pouch (pouch dilation), and
eating high-energy, low-nutrient quality foods can compromise the amount and rate of weight loss, thus
defeating the primary goal of the surgery. As in other treatments of obesity, successful results depend mainly
on long-term motivation, adherence, and behavior modification strategies employed by the patient (1-3).
Types of Bariatric Surgery
A variety of procedures are included under the umbrella term of bariatric surgery. These operations are
categorized as either restrictive or malabsorptive (1-3). The following discussion addresses both categories of
operations and the associated nutrition implications and problems. Nutrition interventions, including
progression of meal planning, should be customized based on the type of procedure (1-3). A detailed overview
of the bariatric diet, nutrition interventions, and meal planning approaches is provided later in this section.