Post-Operative Diet Stages – Duodenal Switch

Everyone transitions along the duodenal switch post-operative diet phases at a different rate as everyone’s body is different. Thus you should refrain from comparing your progress with other BPD/DS patients. You want to be in each phase for a minimum of 7 days with good toleration – no nausea, vomiting, abdominal pain, bloating, or diarrhea.

After that, when you feel ready to move on to the next phase you can. If new items cause nausea or discomfort, discontinue that ingredient. The standard approach to a Duodenal Switch Post-Operative Diet includes a modern sample menu plan. Duodenal Switch is a fairly invasive procedure, so it is important to follow these guidelines to ensure a successful recovery.

Phase One: Clear Liquids

Starts after you pass your leak test and should last 7 days

For 7 days after you pass your leak test, you will need to follow a clear liquid diet. The purpose of this phase is to allow for healing time and to stay hydrated. Fluids will not stretch your stomach. Fluids may cause discomfort or pain in the first couple of days, so it is important to go very slowly. Take about 1 teaspoon at a time, using a measuring spoon or the screw cap of a water bottle. Wait 60 seconds between each sip. It is important to drink at least 4oz per hour to avoid dehydration.

Goal: Stay hydrated – you want to consume a minimum of 48 oz of fluids, optimal goal 64 oz. by sipping small sips 4-8 oz. of water per hour. Learn more about dehydration here.

Drink very slowly and refrain from gulping (“Sips not gulps”). Gradually increase your intake of liquids to 6 to 8 ounces every hour.

  • The clear diet begins immediately after your leak test at the hospital
  • You MUST sip VERY SMALL amounts of fluid ALL DAY
  • Avoid hot or cold liquids – room temperature or warm liquids will be more soothing and help to relax the stomach muscles

Important: You do not weigh your fluids, you measure by volume. You can have as many fluids as your body wants. Fluids will not stretch your stomach.

Recommended Clear Liquids

Sip on liquids throughout the day to stay hydrated and make sure you begin drinking fluids as soon as you wake up in the morning to prevent dehydration. Pay attention to signs of dehydration such as headaches, dizziness, nausea, lethargy, and concentrated (dark) urine.

  • Clear broth/bouillon (chicken, beef, vegetable)

  • Unsweetened caffeine-free herbal tea

  • Sugar-free drinks (Vitamin Zero Water, Powerade Zero, Propel, Crystal Light, etc.)

  • Coconut water (no or low sugar)

  • Zero Sugar Protein WATER drinks (not protein shakes)

  • Sugar-free Jello

  • Sugar-free popsicles

  • Ice chips (2 days after surgery until passing leak test)

  • Alkaline Water (PH level can be more easily tolerated)

  • NO carbonated beverages

**For Duodenal Switch all clear liquid juices need to be sugar-free.


6:30-7:30 AM4 oz water
8:30-9:00 AM2 oz warm broth
9:30-10:00 AM4 oz sugar-free beverage
10:00-10:30 AMSugar-free Jello (counts as 2 oz liquid)
10:30-11:30 AM4 oz water
1:30-2:30 PM6 oz sugar-free beverage
2:30-3:00 PMSugar-free popsicle (counts as 2 oz)
3:00-4:00 PM4 oz water
4:00-5:00 PM4 oz sugar-free beverage
5:00-6:00 PM4 oz warm tea or broth
6:00-10:00 PM14 oz water, 1 sugar-free popsicle (2 oz)

Phase Two: Thick Liquids

Starts 8 days after surgery and can last up to 14 days (7 days minimum)

This stage in your diet allows a broad range of thick liquids and protein supplements. This will give your new pouch and digestive system time to heal properly after the Duodenal Switch procedure and allow you time to adjust. A good rule of thumb for what is allowed on this diet is anything that has the consistency of what can easily be strained through a straw. The consistency should also be very smooth, not chunky. No seeds or nuts for the first 8 weeks.

Recommended Thick Liquids

  • All foods from the previous stage

  • Protein powders & protein shakes

  • Greek yogurt (needs to have more protein than sugar – Fage/Chobani plain, Greek yogurt, or Triple Zero by Dannon-Oikos)

  • Almond or coconut milk

  • FairLife Milk

  • Unsweetened applesauce (No-Sugar)

  • Vegetable juice (V8)

  • Hot cereals like oatmeal/cream of wheat/Kashi hot cereal (try watering it down or add unsweetened almond milk)

  • Sugar-free pudding

  • Soups (higher protein soups like bean soup, if chunky then blend before eating)


BREAKFAST1-2 oz packet high protein oatmeal made with almond milk or Fair Life Milk 1 scoop unflavored whey protein isolate added in
MID-MORNINGProtein shake (minimum of 20 grams of protein) – clear or thick shake
LUNCH4 oz Greek-style yogurt blended with almond milk (choose a yogurt that has less than 5g sugar)
MID-AFTERNOONProtein shake (at least 20g protein)
DINNERPureed bean soup
EVENING4 oz Greek yogurt blended with almond milk

Avoid all carbonated beverages (fills the stomach with gas), sugar (extra calories that fight against weight loss and may cause dumping syndrome), and coffee (it is acidic and may have problems with acid reflux after surgery. It is also a diuretic, causing you to be dehydrated). You may add coffee back in around 12 weeks post-op, only if you’re comfortably consuming 64oz of clear fluids.

Drink a minimum of 48 oz of fluids with a goal of 64 ounces of liquids per day to prevent dehydration. Sport drink bottles with measurements on the side will help ensure you are drinking enough liquid. Remember, sip not gulps throughout the day.

Phase Three: Soft Solids

Starts 15-22 days after surgery and can last up to 14 days, depending on toleration

Chew all your food well to applesauce consistency. If you don’t follow these precautions, you may experience vomiting, stomach irritation, and swelling. You could also have obstruction of the small gastric pouch. If soft solid foods cause nausea and vomiting, go back to the liquid diet you had earlier. Then slowly add soft foods and eventually transition to solid foods. IF VOMITING AND NAUSEA PERSIST, CALL YOUR DOCTOR IMMEDIATELY. 

Goal: You begin to weigh your food at this stage – Your goal is no more than 6 oz of food – 3 oz of protein always and 3 oz of other food (healthy fat, fruits, veggies, etc).

Think of your new pouch as being shaped like a funnel. You can pour any liquid into this funnel and it will run through and out the bottom. The same thing happens with your pouch when you only consume liquids. It is important to not drink your calories or overeat. You should be making this transition to food and weaning off of the protein shakes at this stage. Liquids do not hold in the stomach as long as solid foods, and they do not provide as many nutrients. As a part of your new life, you will want to STOP drinking 30 minutes before a meal and 30 minutes after a meal. Doing so will leave room in your stomach for solid foods and prevent discomfort.

The most important nutrient to eat first at your meals will be a source of protein. Duodenal Switch will cause you to eat less, so it is important to consume protein at all meals.  This will help you reach your protein goal which will keep you full for a longer period of time. Eating a non-starchy vegetable second to protein will help fill you up with nutritious fiber and vitamins and minerals without adding a lot of calories. Prioritizing these two will help to prevent malnutrition and nutrient deficiencies.

  • Your goal is to work towards getting 20 grams of protein at each meal
  • Add only ONE food at a time.
  • The goal for the day is 48-64 oz of fluid to prevent dehydration

Start taking your multivitamins, calcium, iron, and probiotics (optional) daily 2-weeks post-op. Introduce one vitamin at a time, beginning with your multivitamin. If you need guidance in this area or require vitamins please contact us to purchase our recommended vitamins designed for your specific bariatric needs. You can order them here:

Recommended Soft Solids

  • Cottage cheese (low-fat)

  • Ricotta cheese

  • Soft Tofu

  • Scrambled Eggs

  • Egg, chicken, shrimp, tuna salad, salmon

  • Refried beans

  • String/soft cheese like laughing cow

  • Avocado

  • Cooked vegetables


BREAKFAST2 scrambled eggs & 1 oz string cheese (3 oz total)
MID-MORNINGProtein shake
LUNCH3 oz chicken salad 1 oz blended avocado
DINNER4 oz. cottage cheese 1 oz. of fruit blended in
EVENINGProtein shake or sugar-free pudding with protein blended in

Phase Four: Solid Foods

This phase begins 23-30 days or later after the surgery date and continues long-term

Goal: 5-6 oz of food per meal by weight; 3 oz of protein (20 grams), 1 tablespoon of healthy fat, 2 oz to play with.

At this phase, you start back on solid foods. Start with one to four ounces of solid food per meal and then slowly increase the amount of solid food per meal until you are eating at least four ounces per meal but no more than six ounces. It is common to only be able to take a couple of bites at the beginning of this phase, and slowly increase as time goes on.

At each meal, you want to have at least three ounces of protein. In the beginning, mentally identify your protein source. You will find it is easier for non-protein foods to go down, so you may hesitate to eat high-protein foods and gravitate to choosing non-protein foods. Eat three bites of protein to every one bite of something else (three to one rule).

It is easy to get certain foods stuck, so from this phase forward, it will be very important for you to slow down and chew your food thoroughly, pausing between bites. It may be helpful to pause after every bite, put your hands under your legs, and chew until applesauce consistency (around 25 times).

Recommended Solid Foods: 

Eat protein first. Make sure you have three ounces of protein at each meal. Add three ounces of healthy fats, fruits, vegetables, or starches if you can tolerate them. Pay close attention to how you feel about the introduction of new foods. It will be helpful to keep a food diary to see which foods you tolerate best.

Best Tolerated: 

  • Fish
  • Shrimp
  • Eggs
  • Chicken
  • Tofu
  • Meatless products
  • Beans
  • Cottage cheese
  • Low-sugar Greek yogurt
  • Cooked vegetables

Difficult to Tolerate: 

  • Red meat – Items like bacon, sausage, salami, bologna, pastrami, pepperoni, and hot dogs are considered fats, not protein.
  • Raw veggies- Raw veggies are sometimes more difficult to tolerate for the first couple of months, as they are a bit more difficult to digest. It is recommended to wait around 3-4 months post-op before incorporating them.
  • Vegetables with tough skin or seeds, like celery or tomatoes
  • Vegetables like cabbage, cauliflower, or broccoli may cause gas

FRUITS:  With all fruits, eat as part of your meal after you have had at least 3 bites of protein. Remember that the acid in citrus fruits can irritate your pouch. Remember to avoid the membrane portion (skin) of the fruit.

Best Tolerated: 

  • Fresh fruit, peeled with no skin
  • Canned fruit in water or natural juice that has been drained and rinsed

Difficult to Tolerate: 

  • Fruits with skin or seeds

STARCHES: There are two types of starches: whole grains and simple sugars. Focus on eating whole grains, such as:

  • Ezekiel bread
  • Oatmeal
  • Sweet potatoes
  • Quinoa

Minimize simple refined grains, like candy, white rice, pasta, cereals, and processed sugars, including cookies, cakes, and pastries. Additionally “gummy” textured food such as bread and traditional pasta is not tolerated well and can cause blockages. You want to limit the amount of starch you have at each meal to one or two ounces. Be sure that you only eat starch with your protein. Consuming starches first will leave you little to no room for healthy proteins and non-starchy veggies or essential fats, which should always be prioritized after Duodenal Switch surgery.

OILS AND ESSENTIAL FATS: It is important to include essential fats in your daily meal plan to prevent deficiencies. A diet very high in fats should be avoided after Duodenal Switch surgery, it is best to consume a moderate amount of fats. Examples of healthy fats are:

  • Avocado
  • Olives
  • A variety of nuts
  • Oils: olive, grapeseed, or avocado
  • Flaxseeds

Fats to Minimize:

  • Fried foods
  • Saturated fats, like bacon, sausage, pepperoni, salami, and bologna
  • Mayonnaise/Miracle Whip
  • Store-bought salad dressings
  • Sour cream
  • Margarine
  • Butter

These fats should be avoided after duodenal switch surgery, as they may potentially lead to dumping syndrome.

Focus on: 

  • Low-fat cheese (any cheese other than American or Velveeta)
  • All Dried/Canned Beans: kidney, lentil, split pea, pinto, black, etc
  • Lean Meats: fish, tuna, chicken, turkey, pork loin. Make sure all meats are moist
  • Canned fruit in natural juices or soft fresh fruit (peaches, banana, berries, etc)
  • Cooked or non-fibrous raw vegetables
  • Healthy Fats: avocado, nuts, oils, etc.


  • Only add ONE new food at a time!
  • AVOID starchy food like white rice, pasta, bread due to the gummy texture
  • Chew completely and slowly
  • Protein goal is still 60-90g per day
  • Drink at least 6-8 cups of water and any other non-calorie, non-carbonated beverages
  • Stop drinking 30 minutes prior to eating and DO NOT drink until 30 minutes after a meal
  • AVOID all raw fruit with skin, raw fibrous vegetables, and popcorn
  • RECORD all new foods and any problems you have with these new foods in a food diary. Let your doctor know of any problems or questions you may have.
  • CHEW your food very well before swallowing. The consistency of the food should be like mashed potatoes. Make sure that each bite is very small (as if you were feeding a baby) and continue to eat small amounts slowly. Eat about 2 Tablespoons over 10-15 minutes.
  • CONTINUE to take your multiple vitamins, calcium supplements, iron, and B12 supplements as directed
  • AVOID beverages that have alcohol or caffeine and those that are carbonated
  • AVOID using a straw or chewing gum, doing so may cause unwanted air to enter your stomach, and accidentally swallowing your gum can cause a blockage

Duodenal Switch Diet Frequently Asked Questions


General guidelines if you choose to drink alcoholic beverages;

  • Wait 6 months for the body to heal
  • Avoid sugary and large amounts of alcohol, start very gradually
  • Never drink and drive, the absorption may be too unpredictable
  • Be aware of the caloric intake

You are consuming less food now, so alcohol will be absorbed faster. For most patients, a single drink can raise the blood alcohol level to the point of intoxication. It can also cause your blood sugar to drop which is dangerous because you can lose consciousness.

To prevent this, be sure to eat adequate meals before to help ease the absorption, don’t mix drinks with sugary mixers, and if you do hit a low blood sugar moment where you are dizzy and faint please try to dilute juice or take a glucose tablet.  You’ll then want to make sure after you eat a snack with carbohydrates and protein. Alcohol, especially mixed drinks, is very high in calories which may slow your weight loss progress.


Dumping syndrome occurs when foods leave the stomach and enter the intestine too quickly, especially if these foods are high in simple sugars or fat. Dumping syndrome is common with Duodenal Switch. Once the food is in your intestine, the intestine will pull water from other parts of your body in an attempt to dilute the concentration of sugar or fat in your digestive system; this process creates numerous, unpleasant symptoms.

Early signs of dumping syndrome are abdominal fullness, abdominal cramping, and nausea. You may feel warm, dizzy, weak, or faint. You may also experience a rapid heartbeat and break out in a cold sweat. Often dumping syndrome is accompanied by diarrhea, but not always.

To prevent dumping syndrome, you will need to avoid eating too much simple sugar and/or too much fat at a meal, especially Duodenal Switch patients. You must also eat slowly, as eating too fast can cause dumping syndrome. Each individual will likely tolerate a different amount of simple sugar and/or fat. For this reason, you will need to learn what your own limits are by paying attention to the sugar and fat content of your meal and keeping a food journal.

Refer to the nutrition facts label of the product. If the product has less than 5 grams of sugar, this will likely be a well-tolerated food or beverage.

Foods and beverages that naturally contain sugar (such as milk, fruit, and starchy vegetables) are typically tolerated; however, the dumping syndrome may occur if the portion sizes are too large.

Learn more: Dumping Syndrome Guide: Symptoms, Diagnosis, and Treatment Options


One of the main causes of nausea and vomiting after surgery is not following the nutrition guidelines. Any problems with nausea or vomiting should prompt the following questions and necessitates changes to avoid further pain and discomfort:

  1. How long am I taking to eat and/or drink?
  2. Am I eating and/or drinking slowly enough?
  3. Did I drink fluids with my meal or too soon before or after the meal?
  4. Am I eating more than I should?
  5. Do I continue to eat after I feel satisfied?
  6. Am I chewing solid foods until they resemble a pureed consistency?
  7. Did I lie down too soon after my meal?
  8. Did I eat hard-to-digest foods such as tough meat or untoasted bread products?
  9. Did I eat foods from the next diet phase before being cleared by my physician/nutritionist?

If you vomit, return to sugar-free, clear liquids (Phase 1). If you’ve said “yes” to any of the questions above, consume liquids until solid food is once again comfortable to eat. Repeated vomiting may cause stress on the new stomach and result in irritation or— even worse— rupture of the staple line. If vomiting persists throughout the day and/or you’ve answered “no” to all the above questions and the vomiting is not improving, call or email the surgical liaison.

Learn more: 13 Ways to Stop Nausea and Vomiting


After BPD/DS, diarrhea is caused by fatty acids passing directly into the colon. These fatty acids would normally have been absorbed in the small intestine. Once in the colon, they induce irritation. Another contributing factor is sorbitol, found in fruits, berries, and also used as an artificial sweetener. Sorbitol is not well absorbed in the GI tract, and when in the colon, it is fermented. Diarrhea is more common in Duodenal Switch patients.

Reducing the amount of fat will usually have a direct beneficial effect on the number and quality of bowel movements a patient may have. Management of diarrhea (provided there is no identifiable pathologic etiology or dietary factor) is varied. A dose of Imodium at bedtime can decrease the number of early morning bowel movements. It may also delay the onset in those who have been previously awakened early in the morning by urgent bowel movements.

If beneficial, some patients may stay on a maintenance dose of Imodium® or Lomotil® for long-term control. Many patients will benefit from a course of probiotics after bariatric surgery. Garden of Life and Align are the recommended brands of probiotics. It is suggested to supplement with 50 billion CFU or higher; the higher the number of strains, the better.


Lactose intolerance is the inability to digest large amounts of lactose, the major sugar found in milk products. Common symptoms of lactose intolerance include nausea, cramps, bloating, gas, and diarrhea. Symptoms begin anywhere between 30 minutes to 2 hours after eating or drinking foods containing lactose.

Most adults do not have to avoid lactose completely, but people differ in the amounts and types of foods they can handle. For example, one person may have symptoms after drinking a small glass of milk, while another can drink one glass but not two.

The level of dietary control needed with lactose intolerance depends on how much lactose a person’s body can handle. To avoid symptoms associated with lactose intolerance, use lactose-free low-fat milk or unsweetened non-dairy milk (almond, soy, rice, etc.) instead of low-fat cow’s milk. Lactose intolerance is common in the early stages of healing after Duodenal Switch surgery.

Learn more: Can Lactose Intolerance Occur After Bariatric Surgery?

We hope that this information proves useful to you. If you have any questions you are welcome to contact us at any time.

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