Nutrition Management in Bariatric Surgery
Manual of Clinical Nutrition Management B- 20 Copyright © 2013 Compass Group, Inc.
Soft. Other modifications may be needed to promote individual tolerance and weight loss, such as Lactose-
Controlled Diet, Sugar in Moderation Diet, Low-Fiber Diet, Low-Fat Diet, or other strategies discussed in
Planning the Diet.
Planning the Diet
Limited scientific evidence is available to support specific guidelines and strategies for nutrition intervention
following bariatric surgery. The existing guidelines are based on emerging evidence from bariatric centers
and institutions that specifically provide bariatric surgical procedures and long-term obesity management (1).
The guidelines are based on scientific evidence and identified nutrition intervention strategies that are
effective in managing postsurgical bariatric surgery patients. “Bariatric Diet” is a general term for the overall
diet approach applied to all patients following a bariatric surgery. Meal planning should be customized based
on the type of procedure and the individual patient’s needs. In addition, the clinician can refer to the
summary by Mechanick et al for specific meal progression plans for laparoscopic adjustable gastric banding,
Roux-en-Y gastric bypass, and biliopancreatic diversion gastric bypass (1). The Bariatric Diet meal plan
incorporates the following nutritional guidelines (1).
Energy requirements: Total energy requirements are based on the postoperative stage, progression of meal
plan, and volume of food tolerated. Ensuring nutrient quality is the primary goal when designing the meal
plan.
Protein should provide at least 25% of the total energy intake (or 60 to 120 g/day of protein or 1.5 g/kg
of ideal body weight) to minimize lean muscle loss during rapid weight loss (1). Modular protein
supplements may be required during the first 6 postoperative months until solid food intake is sufficient
to meet the protein requirements (1).
Fats should provide 25% to 30% of total energy. Small amounts of dietary fat, along with prescribed
medication, can help maintain gallbladder emptying and reduce the risk of gallstone formation (5).
Carbohydrates should provide approximately 50% of the daily energy intake. The intake of concentrated
sugars should be limited for gastric surgery patients. Concentrated sweets or sugary foods should be
avoided after Roux-en-Y gastric bypass to minimize the symptoms of dumping syndrome or after any
bariatric procedure to reduce the energy intake (1). Foods that provide low-quality nutrients with high
amounts of energy and fat may compromise the primary goal of promoting weight loss.
After a diet of full liquids or semisolid food begins (usually 2 to 3 days postoperatively), initiate a
chewable multivitamin and mineral supplement regimen (one or two supplements per day) that provides
100% of the DRIs for age and sex. Additional specialized supplementation may be required for iron,
calcium (1,200 to 2,000 mg/day), vitamin B12, folate, or other vitamins and minerals as indicated by
laboratory assessment and the ability to consume food sources (1). Patients who have extensive
malabsorption will have even higher supplementation requirements for vitamin D, calcium, and vitamin
B 12 and possibly thiamin, copper, and vitamin A (1,5).
Initially, the meal plan should provide multiple small meals each day, with the focus of chewing food
thoroughly without drinking beverages at the same time; beverages should be consumed more than 30
minutes before or after solid foods (1,5).
Volume and consistency: The volume and consistency of foods provided depend on the postoperative stage
and individual tolerance. Initially, 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 (½ to 1 cup).
Fiber: High-fiber foods may not be initially tolerated. Fiber should be gradually introduced based on the
patient’s progress toward the consumption of solid foods and a regular diet (usually more than 6 to 8 weeks
after surgery). Patients should adhere to a balanced meal plan that includes more than five daily servings of
fruits and vegetables for optimal fiber consumption, colonic function, and phytochemical consumption (1).
Anecdotal evidence suggests that bulky foods, such as bran, popcorn, raw vegetables, and dried beans, should
be avoided or limited based on individual tolerance or until the diet progresses and tolerance of these foods is
verified.
Fluid: Adequate consumption of fluids is essential to prevent dehydration. A minimum of 1.5 L or 6 cups (48
oz) should be consumed each day (1). When the patient is able to consume pureed or solid foods, fluids should
be consumed at least 30 minutes before or after meals to prevent nausea and vomiting (1). Fluids should
consist of water or controlled-energy (low-sugar, low-fat, or diet) beverages. Caffeine-containing beverages