Manual of Clinical Nutrition

Nutrition Management in Bariatric Surgery

Manual of Clinical Nutrition Management B- 23 Copyright © 2013 Compass Group, Inc.

at each meal (approximately 10 g per meal) can be helpful in maintaining gallbladder emptying and
preventing gallstone formation (5,11,12). Gallstones can also be prevented with supplemental bile salts (eg,
ursodiol orally administered 300 mg twice per day) taken for the first 6 months after surgery (1). Long-term,
a prudent low-fat diet following the National Cholesterol Education Program Adult Treatment III guidelines
should be advocated to sustain weight loss and reduce risk factors for other comorbid conditions (1).

Carbohydrate: Carbohydrates should provide approximately 45% to 50% of total energy. Carbohydrates
help to prevent the loss of lean tissue (15). While carbohydrate intake does not have to be high, it is suggested
that energy-restricted diets contain more than 100 g/day of carbohydrate to minimize ketosis (15).
Hyperuricemia can also result from weight loss, particularly with the use of a low-carbohydrate diet. Ketone
bodies, products of fat oxidation in the energy-restricted patient, compete with urate for tubular reabsorption
in the kidney, resulting in increased uric acid levels and an increased risk of gout. Increasing the
carbohydrate content of the diet will reduce the risk of increasing uric acid levels (19). Sugar intake should be
limited; sugars are generally not tolerated and can cause symptoms associated with the dumping syndrome
(1). In addition, sugary foods often provide low-quality nutrients and high amounts of energy and fat. Foods
to avoid or limit include candy, cookies, ice cream, milkshakes, slushes, soda pop, sweetened juices or gelatin,
and most desserts.

Fiber: Anecdotal evidence suggests that high-fiber foods are generally not tolerated and should be avoided
until progression to regular foods has occurred (usually >6 to 8 weeks postoperatively). Bulky foods, such as
bran, popcorn, raw vegetables, and dried beans, may need to be avoided until individual patient tolerance is
verified. It is thought that the newly created surgical pouch does not have the capacity to hold many of these
foods. In addition, gastric acid is reduced and may not be as readily available to help digest fibrous foods.
However, more recent guidelines recommend that patients should be advised to adhere to a balanced meal
plan that contains more than five servings of fruits and vegetables daily for optimal fiber consumption,
colonic function, and phytochemical consumption (1).

Vitamins and minerals: Because the Bariatric Diet allows only a small amount of foods and limits the types
and variety of foods, vitamin and mineral supplementation is necessary. Immediately after a full liquid or
semisolid food diet begins (usually 2 or 3 days after surgery), a patient should begin supplementation with a
chewable multivitamin and mineral supplement that provides 100% of the appropriate DRIs for the patient’s
age and sex (1). For gastric bypass procedures that cause malabsorption (eg, Roux-en-Y, biliopancreatic
diversion, and biliopancreatic diversion with duodenal switch), additional supplementation may be required
for key nutrients whose absorption is impacted, predominately iron, folate, vitamin B12, and calcium (1), or
other vitamins and minerals as indicated by routine laboratory assessment. The Roux-en-Y and
biliopancreatic diversion procedures have a greater impact on nutrient absorption because of the anatomical
alterations and the impact on gastric acidity (1,17,20). Because these procedures can lead to metabolic bone
disease, routine diagnostic testing is recommended so that the appropriate intervention can be delivered (1).
For patients who have Roux-en-Y or biliopancreatic diversion procedures, vitamin and mineral supplement
regimens that contain higher doses of iron, calcium, vitamin B 12 , and folate are often indicated (17,20). Intakes
of 40 to 65 mg of elemental iron (1,17) and 800 to 1,000 μg of folate per day have been recommended (17,21). An
average daily dose of 350 μg of sublingual vitamin B 12 maintains adequate stores (1). Although this dose is
175 times the DRI, a small percentage of patients will still become vitamin B 12 deficient and require monthly
intramuscular injections (1,17,20,21). Calcium supplements of 1,200 to 2,000 mg/day plus 400 to 800 IU/day of
vitamin D should be provided to all patients following bariatric surgery (1,17). Calcium citrate with vitamin D
is the preferred preparation because it is more soluble than calcium carbonate in the absence of gastric acid
production (1,21,22). Calcium should be divided into doses of no more than 500 mg throughout the day (17). For
patients with the biliopancreatic diversion procedure who have clinical steatorrhea, a high-dose calcium
supplementation regimen (2,000 mg/day) and a monthly intramuscular vitamin D injection is recommended
to reduce the risk of metabolic bone disease (17). Patients who have the biliopancreatic diversion procedure
must also take supplements of fat-soluble vitamins A, D, E, and K, if clinically indicated (5). (Refer to Table B- 1
(1).) In addition, the summary by Mechanick et al outlines recommended medical testing and routine
evaluation and monitoring for nutritional deficiencies that may occur specific to malabsorptive bariatric
surgical procedures such as Roux-en-Y gastric bypass, biliopancreatic diversion, or biliopancreatic diversion
with duodenal switch (1). Signs and symptoms of nutritional deficiencies should be routinely evaluated and
monitored postoperatively to determine if additional vitamin or mineral supplementation is necessary (1).