What Should You Eat After Gastric Bypass Surgery?

There is a certain amount of healing that is necessary after having gastric bypass surgery (Roux-en-Y gastric bypass 1). In order to assist with the recovery, the gastric bypass diet is typically suggested. Following this diet will also help to change eating habits.

This diet will be discussed with you by your doctor or a registered dietitian. They will let you know how much food you will be eating at each meal and the types of food that are acceptable. If you follow the gastric bypass diet closely, it will help you to safely lose weight.

The Gastric Bypass Diet

What is the purpose of the gastric bypass diet?

1. The diet keeps your stomach from stretching and helps it to heal.

2. Allows you to adjust to eating smaller amounts of food so your stomach can comfortably accommodate it and safely digest it.

3. Assist with weight loss and prevent weight gain.

4. Reduce complications and possible side effects of gastric bypass surgery.

What is the gastric bypass diet?

The gastric bypass diet 2 allows you to get back to eating solid foods by following a staged approach. The speed that your body heals and adjusts to your new eating pattern will dictate how quickly you move from one stage to the next. Most people are able to start eating regular foods about three months after you have surgery.

Each individual will get their own specific recommendations for the gastric bypass diet.

You should be careful to do the following during each stage of the gastric bypass diet:

1. Drink 64 ounces of fluid a day, to avoid dehydration.

2. Sip liquids between meals and avoid liquids with meals. 30 minutes should pass after a meal before you drink anything. You should also not drink anything 30 minutes before a meal.

3. Dumping syndrome, which is when food and liquid enter into the small intestines rapidly and in larger amounts can be avoided by eating and drinking slowly. It helps you to avoid nausea, vomiting, dizziness, sweating, and diarrhea.

4. The diet includes lean, protein-rich foods and should be followed daily.

5. Choose low fat and sugar foods and drinks.

6. No alcohol.

7. Avoid drinking too much caffeine because it could lead to dehydration.

8. Follow the vitamin and mineral supplement regimen provided by your health provider.

9. Chew your food thoroughly until a pureed consistency before swallowing after you start adding solid food to your diet.


You will only be allowed to drink clear liquids for the first day or so after surgery. When you are accustomed to drinking clear liquids, other liquids may be added.

  • Broth
  • Unsweetened juice
  • Decaffeinated tea or coffee
  • Milk (skim or 1 percent)
  • Sugar-free gelatin or popsicles
  • Pureed Foods

After you have been tolerating liquids for about a week then strained and pureed foods will be added to your diet. They will be the consistency of a thick liquid or smooth paste with no solid pieces of food included.

Three to six small meals can be eaten per day, with each meal being between 4-6 tablespoons of food. Eat slowly, taking 30 minutes to eat each meal.

Pureed Foods

  • Lean ground meat, poultry or fish
  • Cottage cheese
  • Soft scrambled eggs
  • Cooked cereal
  • Soft fruits and cooked vegetables
  • Strained cream soups

Blend solid foods with a liquid, such as:

  • Water
  • Skim milk
  • Juice with no sugar added
  • Broth

Soft Foods

After eating pureed foods for a few weeks, your doctor might give you the green light to begin adding soft foods. They should be tender, small and easy to chew pieces of food.

Anywhere from three to five meals per day can be consumed. They will be one-third to one-half cup of food per meal. Chew each bite to a pureed consistency before you swallow.

Soft foods include:

  • Ground lean meat or poultry
  • Flaked fish
  • Eggs
  • Cottage cheese
  • Cooked or dried cereal
  • Rice
  • Canned or soft fresh fruit, without seeds or skin
  • Cooked vegetables, without skin

Solid Foods

Approximately eight weeks after starting the gastric bypass diet you might be given the ok to gradually add solid foods into your diet. Begin by eating 3 meals daily of between 1 - 1/2 cups of food. Do not eat until you feel completely full.

The way you tolerate solid food will make a difference in the amount of food you can eat and the number of meals. You dietitian should be consulted about what's best for you.

Try new foods one at a time. You might have pain, nausea or vomiting with trying certain foods.

Foods that can cause problems at this stage include:

  • Bread
  • Carbonated drinks
  • Raw vegetables
  • Cooked fibrous vegetables, such as celery, broccoli, corn or cabbage
  • Tough meats or meats with gristle
  • Red meat
  • Fried foods
  • Highly seasoned or spicy foods
  • Nuts and seeds
  • Popcorn

You might be able to try some of these foods again but be sure to talk to a doctor first.

What to Eat After Gastric Bypass Surgery

The size of your stomach is reduced with gastric bypass surgery. It also changes how food enters the intestines. Get adequate nourishment after surgery and pay careful attention to your weight loss goals.

Your doctor is likely to recommend that you:

  • Eat and drink slowly: To avoid dumping syndrome, take at least 30 minutes to eat your meals and 30 to 60 minutes to drink 1 cup of liquid. Wait 30 minutes before or after each meal to drink liquids.
  • Keep meals small: Eat several small meals a day. You might start with six small meals a day, then move to four meals and finally, when following a regular diet, three meals a day. Each meal should include a half-cup to 1 cup of food.
  • Drink liquids between meals: To avoid dehydration, you'll need to drink at least 8 cups (1.9 liters) of fluids a day. But drinking too much liquid at or around mealtime can leave you feeling overly full and prevent you from eating enough nutrient-rich food.
  • Chew food thoroughly: The new opening that leads from your stomach into your small intestine is very narrow and can be blocked by larger pieces of food. Blockages prevent food from leaving your stomach and can cause vomiting, nausea and abdominal pain. Take small bites of food and chew them to a pureed consistency before swallowing.
  • Focus on high-protein foods: Eat these foods before you eat other foods in your meal.
  • Avoid foods that are high in fat and sugar: These foods travel quickly through your digestive system and cause dumping syndrome.
  • Take a Bariatric Multivitamin: After surgery, your body won't be able to absorb enough nutrients from your food. You'll likely need to take a Bariatric Multivitamin every day for the rest of your life.

What Results to Expect

Following the gastric bypass diet after surgery can help you to recover and supports your goals of losing weight 3. If you deviate from the diet and start eating in an unhealthy way, you might not reach your weight loss goals and you could regain any weight you have lost.

What are the Risks?

Not following the diet properly typically poses the greatest risk. If you eat foods you shouldn't or eat too much, you might experience complications, including the following:

  • Dumping syndrome: If too much food enters your small intestine quickly, you are likely to experience nausea, vomiting, dizziness, sweating, and diarrhea. Eating too much or too fast, eating foods high in fat or sugar, and not chewing your food adequately can all cause nausea or vomiting after meals.
  • Dehydration: Because you're not supposed to drink fluids with your meals, some people become dehydrated. That's why you need to sip 64 ounces (1.9 liters) of water and other fluids throughout the day.
  • Constipation: A lack of physical activity and of fiber or fluid in your diet can cause constipation.
  • Blocked opening of your stomach pouch: Food can become lodged at the opening of your stomach pouch, even if you carefully follow the diet. Signs and symptoms of a blocked stomach opening include ongoing nausea, vomiting, and abdominal pain. Call your doctor if you have these symptoms for more than two days.
  • Weight gain or failure to lose weight: If you continue to gain weight or fail to lose weight on the gastric bypass diet, talk to your doctor or dietitian.