Nutrition Management in Bariatric Surgery
Manual of Clinical Nutrition Management B- 24 Copyright © 2013 Compass Group, Inc.
Table B-1: Routine Nutrient Supplementation After Bariatric Surgerya
Supplement Dosage
Multivitamin One to two daily
Calcium citrate with vitamin D 1,200-2,000 mg/day of calcium plus 400-800 IU/day of vitamin D
Folic acid 400 mcg in multivitamin
Elemental iron with vitamin Db 40 - 65 mg/day
Vitamin B 12 >350 mcg/day orally
or 1,000 mcg/month intramuscularly
or 3,000 mcg every 6 months intramuscularly
or 500 mcg/week intranasally
aPatients with preoperative or postoperative biochemical deficiencies require additional supplementation (1).
bFor menstruating women
Adapted from: Mechanick JI, Kushner RF, Sugerman HJ, Gonzalez-Campoy JM, Collazo-Clavell ML, Guven S, Spitz AF, Apovian CM,
Livingston EH, Brolin R, Sarwer DB, Anderson WA, Dixon J. Executive summary of the recommendations of the American Association of
Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery medical guidelines for clinical
practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient. Endocr Pract.
2 008;14:331.
Studies have found a significant correlation between eating habits (quality of food consumed) and
laboratory values (1,15,20). In a study of patients who received a Roux-en-Y gastric bypass, the mean levels of
serum iron saturation, vitamin B 12 , and folic acid were significantly higher in patients who ate meat than in
patients who did not eat meat (15). Iron status continued to decline 6 to 8 years after surgery, depending on
eating behavior (15). Oral vitamin and mineral supplementation significantly improved the nutritional status
of the study patients (15). Patients who have biliopancreatic diversion or biliopancreatic diversion with
duodenal switch procedures should be evaluated frequently to assess benefits or improvements in nutritional
outcomes following bariatric surgery (1).
Fluids: Adequate consumption of fluids is essential to prevent dehydration. A minimum of 6 cups (48 oz)
should be consumed per day, with a goal of consuming 64 oz/day (1,5,20). Patients should initially consume 2
to 3 oz at a time and gradually increase their fluid intake to 3 to 4 oz at a time 8 weeks after surgery (1,5,20).
Once pureed or solid foods are introduced into the diet, fluids should be consumed at least 30 minutes before
meals and should consist of water or energy-controlled (low-sugar, low-fat, or diet) beverages. The patient
should delay drinking beverages with food; rather, the patient should wait at least 30 minutes after meals to
prevent increasing the transit time of food through the pouch, which may lead to nausea and vomiting (1).
After 6 to 9 months, most patients can tolerate drinking fluids with meals. Intake of caffeine-containing
beverages and carbonated beverages should be individualized according to the patient’s tolerance.
Volume, consistency, and timing: The volume and consistency of foods depend on the postoperative stage
and individual tolerance. Initially after gastric bypass surgery, the stomach can hold only 1 to 2 oz (2 to 4
tbsp). Over time, the stomach pouch will stretch until it can hold 4 to 8 oz (or about ½ to 1 cup). The
Bariatric Diet progresses in stages from clear liquids (1 to 2 days) to full liquids and pureed foods (4 to 6
weeks) and then to soft and regular foods (6 to 8 weeks). The timing of progression varies among patients, so
it is appropriate for individuals to adjust their own progress depending on how they feel. Four to six small
meals per day may be better tolerated long term; however, coordinating the meals with fluid intake may be
challenging and should be individualized (5). After the pouch matures (6 months), most food consistencies
can be tolerated. (Refer to Table B-2.)
Food intolerances: Patient reports have indicated common postoperative intolerances to specific foods (23-
25). Red meat, milk, and high-fiber foods are among the foods most commonly reported as not well tolerated.
One study found meat intolerance in 51% of patients during postoperative months 0 to 12; 60.3% of patients
at 13 to 24 months; 59.5% of patients at 25 to 72 months; and 55.1% of patients at 73 to 96 months (15). Soft
breads are often not tolerated. However, crispy breads and crackers (eg, well-toasted breads, Melba toast,
and low-fat crackers) are generally better tolerated. Milk intolerance may be caused by an intolerance to fat
or a secondary lactose deficiency related to the surgical procedure (1,5,23-25). Fat-free milk in small amounts is
suggested to improve tolerance. Individual meal planning should be accommodated to meet nutrient-specific
needs if certain foods are not tolerated.