Sunday February 25, 2024

Duodenal Switch Diet

Duodenal switch patients are able to enjoy a wide variety of foods from all food groups, but will also be expected to make permanent changes to diet and eating habits after surgery. Choosing healthy foods and taking vitamin and mineral supplements will be important aspects of maintaining good health and promoting weight loss.

Daily supplements are necessary
lifelong to maintain good health.

Specific diet plans will vary between patients and bariatric surgeons and your nutritional advisor will help you plan a healthy diet based on your personal situation. Although patients should always follow the advice provided by their health care provider, the following nutritional guidelines highlight the general aspects of a duodenal switch diet.

Eating Basics

Grilled Steak

After duodenal switch surgery, you will need to learn a new way of eating. The changes made to the digestive system will affect how much food you can eat, what types of food you can eat, and how you eat for the rest of your life. It may take a period of adjustment for your body to adapt, but eventually it will become accustomed to the new eating habits and behaviors.

  • Portion Control: It is important to avoid overeating - stop eating when you feel full. After surgery the stomach can only hold 4 to 6 ounces of food, or 2 to 3 tablespoons at one time. The stomach will slowly stretch over the months following surgery, gradually allowing you to eat more regular sized meal portions. It can take about 9 to 12 months for the stomach size to stabilize.
  • Food Choices: Every bite counts - feed the body with the nutrients it needs and avoid empty calories. A typical diet consists of high-protein foods with sides of fruits, vegetables, and whole grains. Foods that should be avoided are high-fat foods, refined carbohydrates, and concentrated sweets.
  • Eating Behaviors: Adopting new eating behaviors aids weight loss. Schedule three meals and one high-protein snack per day, plan menus ahead of time, and avoid snacking throughout the day. When eating, eat slowly and chew food thoroughly to aid with satiety and digestion. Also, avoid drinking beverages within a half-hour before or after eating, to allow room for food.

Diet Progression After Surgery

Your diet after surgery will slowly progress from clear liquids, to purees, then to soft foods as your body heals from surgery and adjusts to the digestive changes. It can take up to a month or two before your body will tolerate solid foods. Throughout the recovery process, it is important to follow the guidelines of your bariatric surgeon and only reintroduce foods to your diet when informed it is appropriate to do so.

  • Duodenal switch (hospital) clear liquid diet: The first few meals after surgery will consist of clear, sugar-free liquids, such as water, tea, broth, sugar-free jello. Liquids should be sipped slowly at the rate of 1-1/2 to 3 ounces per hour.
  • Bariatric surgery (hospital) pureed diet: Once the body is able to tolerate liquids, you will be given pureed foods such as cottage cheese and unsweetened applesauce. Portion sizes should be limited to 2 to 3 tablespoons.
  • Duodenal switch soft food diet: When you leave the hospital, your home diet will consist of soft foods for about 3 to 4 weeks. Soft food items include meatloaf, moist fish, eggs, low-fat cottage cheese, oatmeal, crackers, unsweetened applesauce, ripe bananas, soft-cooked vegetables (not corn), and sugar-free puddings.
  • Duodenal switch modified diet: Once you are able to tolerate all the foods on your soft diet, you will then gradually advance to your new post-surgery diet. New foods are typically added to the diet one at a time to avoid intolerance. The diet progression at this stage is very individualized, but at one year post-op most patients are able to enjoy a wide variety of foods from all food groups.

Foods You Can Eat

Duodenal switch patients are able to eat a wide variety of foods from all food groups, but it is important to choose foods wisely based on high nutrient value and low calorie content.

Duodenal switch
patients are able to
enjoy a wide variety
of foods from all
food groups and are
generally able to eat
dense, high-protein
foods such as steak
without difficulty.

A typical duodenal switch diet consists of three high-protein nutrient dense meals and one high-protein snack each day. Protein is the most important diet nutrient and should always be the first food item eaten. Protein supplements can also be used to meet daily protein requirements.

  • The recommended amount of protein for duodenal switch patients is around 90 grams each day.

Common sources of protein are lean meats, veal, poultry, fish, soy products, eggs, cheeses, yogurt, legumes, and nuts. Unlike gastric bypass patients, duodenal switch patients are generally able to eat dense, high-protein foods without difficulty including beef, steak, pork, and stew meat.

Although protein foods are the focus of meals, the diet should also include a variety of fruits, vegetables, and whole grains. Patients are usually able to eat fibrous vegetables, bread, and pasta without difficulty or getting stuck in the stomach. Dietary fat is best derived from monounsaturated (canola, olive, and peanut oils, avocados) or polyunsaturated (corn, safflower, peanut, soybean and sunflower oils) sources and low-fat dairy products.

Food Intolerance

The changes to the digestive system may cause some individuals to develop a food intolerance to certain food products. When foods are added to the diet after surgery, they should be introduced one at a time to rule out an intolerance. If a food is not well tolerated, it can be tried again in one week.

One of the more common reactions is an inability to handle lactose (milk sugar), resulting in gas and diarrhea. Patient who become lactose intolerant may find it easier to digest non-fat dairy products or lactose-free milk. Lactase pills are also available to help with lactose digestion.

Food intolerance and unpleasant side effects from different foods varies from patient to patient, so your experience may be different from the response of others.

Foods to Avoid

After recovery, almost all foods can be eaten without the incidence of stoma blockage or dumping syndrome that is common with gastric bypass surgery. However, some types of food should be avoided because they either are high in calories or cause unpleasant side effects.

  • Avoid high fat foods: greasy, fried, high fat foods are unhealthy and undermine weight loss efforts; high fat foods may cause diarrhea or increased bowel movements as fat is not completely absorbed by the digestive system; avoid saturated fats (butter and other animal products) and trans fatty acids (margarine and shortening)
  • Avoid concentrated sugars: foods and beverages with high sugar content are full of empty calories that do not provide nutrients to the body and slow down weight loss (artificial sweeteners such as nutrasweet, saccharin, and sucralose are okay to use)
  • Limit carbohydrates and starchy foods: carbohydrates and starchy foods, such as pasta, may cause gassiness as undigested carbohydrates in the colon is broken down by bacteria into gaseous by-products

Lemon Water


To keep the body hydrated, duodenal switch patients should drink at least 6 to 8 cups (8 oz) of fluid each day. Signs of dehydration include headache, dizziness, nausea, lethargy, dark urine, whitish coating on the tongue, and lower back pain.

Acceptable beverages include water, skim milk, decaf coffee and tea, broths, and sugar-free beverages (Crystal Light, Diet Snapple, sugar free Kool-Aid, sugar-free Tang, sugar-free vitamin water, flat diet soda).

Liquids should be sipped throughout the day to avoid becoming dehydrated. Do not drink within half an hour before or after eating otherwise there will not be room for food and the fluid will interfere with digestion. Also, using a straw may cause gas and should not be used.

Nutritional Supplements

Duodenal switch patients will need to take daily vitamin and mineral supplements for the rest of their lives in order to maintain health. The body is not able to absorb the nutrients it needs to function due to bypassing a large portion of the small intestine. Typical supplements include a multivitamin, ADEK's, calcium, and iron. Protein supplements may also be recommended. Your bariatric surgeon will monitor you on a regular basis to make sure you are maintaining the proper level of vitamins and minerals.


  • Diet Guidebook for DS, University of Minnesota Medical Center, Fairview
  • Nutritional Guidelines for Roux-en-Y and Duodenal Switch Gastric Restrictive Procedures, University of Chicago Medicine
  • American Society for Metabolic and Bariatric Surgery, The Story of Obesity Surgery, Chapter 4, Biliopancreatic Diversion and Duodenal Switch.
  • "The Duodenal Switch Revisited", Weill Medical College of Cornell University, Bariatric Times, June 2009

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Nutrition Tips

Always be prepared with ready to eat healthy foods. If you find that preparation is a stumbling block, buy pre-cut, pre-washed fruits and vegetables, such as baby carrots, melon bowls, or salads in bags; treat yourself to a favorite fruit for dessert, and don't be afraid to try exotic or tropical fruits for variety.

The main reasons that patients chose gastric bypass surgery were more overall weight loss, quicker weight loss, and felt it was better for them.