Gastric sleeve post-op diet: stages explained one by one

Chapter 3

After your surgery, you need to follow a gastric sleeve post op diet. The surgery results in a smaller stomach and a renewed digestive system. To help it in its pace, this diet plan was prepared especially for gastric sleeve patients.

There will be stages of this diet plan to help your stomach adjust and heal. It will go back to normal in time. To maximize the results of gastric sleeve, you should follow this diet with utmost care. 

This will be the last (but not least) part of our gastric sleeve diet journey. Even if the pre-operative diet is not a must, this post-op will be. Let’s go!

What is gastric sleeve post op diet?

Post gastric sleeve diet is a crucial part of the gastric sleeve recovery process. Your digestive system is going through changes. And during this period, you need to allow it to heal gradually. As time goes on, your food tolerance will improve.

You will go through this program for 1-2 months. This can vary from person to person regarding their age, recovery progression, and other underlying factors. You should be eating 3 meals per day and have snacks 2-3 times a day. For snacks, your dietitian will provide you with a list of healthy food options.

After 3 months, you will switch to a more varied diet plan. And after that, you will keep on going on with experimenting with food options.

gastric sleeve post op diet

What are gastric sleeve food stages?

There are 5 stages of gastric sleeve post op diet. The density and variety of your food intake will change from stage to stage. It is essential to follow these stages accordingly. Because these stages are prepared specially for gastric sleeve patients.

It is important that you stop eating as soon as you start feeling full. It’s okay that you did not clear your plate. In time, you will learn to portion your food accordingly with your ability to intake certain amounts of food with your sleeve. At the start, you will be able to consume half a cup of food per meal. Later on, you will be able to consume 1 cup size portions of food. Also, you must not eat and drink at the same time.

There are going to be certain rules that you need to follow during your gastric sleeve post op diet. For 3 months, you are not allowed to eat or drink:

  • Raw fruits and vegetables
  • Whole red meat or beef
  • Citrus fruits such as oranges and lemon
  • Legumes such as lentils and chickpeas
  • Any kind of rice, pasta, and barley
  • Dried fruits
  • Sugary or salty snacks
  • Nuts
  • Carbonated and/or sugary beverages
  • Coffee (you can start drinking decaf after a month, one cup a day only!)
  • Alcoholic beverages

Stage 1: Clear liquid diet

This stage is referred to as the gastric sleeve liquid diet. You will start this stage the day you are discharged from the hospital and it will last 10 days. During this stage, you will consume clear liquids.

You are not allowed to consume the following:

  • Spices except for salt. Other spices like powdered pepper can upset your stomach.
  • Vegetables that can cause gas buildup, such as cabbages
  • Anything too hot or too cold, room temperature is recommended
  • Onion or garlic, cooked or raw
  • Dairy products

Here is the list of things you can consume in the 1st stage:

  • Water
  • Tea (not too dark)
  • Compote without sugar or grain
  • Fresh fruit juice without added sugar
  • Protein water, do not confuse it with a protein shake
  • Broth (chicken, veggie, bone, fish)

Stage 2: Semi-liquid – semi-puree diet

At this stage, you prepare yourself for the pureed food. And you will be actually consuming thicker liquids. It should be done moderately, so that your stomach does not get upset. This stage will last for 3-5 days.

Let’s examine what you can have:

  • Peeled fresh fruit juice without filtering, like a smoothie.
  • Soups
  • Yogurt (fat-free or lactose-free)
  • Protein shake (with fat-free, lactose-free, soy milk, almond milk, or oat milk)
  • Probiotic yogurt (plain)
  • Kefir (plain)

As a side note here, you can have tomato, fish, chicken, vegetable, yogurt, and other kinds of soups that do not include cream, onion, spices, and vegetables that can cause gas buildup. Homemade soups only. Make sure there are no grains and blend the soup well. Also, you can add potatoes and carrots to your soup, but not often. And do not add too many of them.

How to choose the best protein shake

Some surgeons recommend to their patients the protein shakes that they are supplying. If your surgeon does not, you should look for protein shakes that are low in fat and calories, and high in protein.

The protein shake’s calorie range should be between 160200 and it should contain around 5060 grams of protein. You can get flavored protein shakes, provided they do not contain lots of sugar. It is recommended that you consult your dietitian about the protein shake choice you make.

Stage 3: Puree diet

In stage 3, you will be starting to consume pureed food. This pureed diet gastric sleeve stage will last 1 week. This is where you will be starting not drinking and eating and the same time. Because, although not quite, pureed food is moderately solid. You should stop drinking 30 minutes before your meal and start drinking 30 minutes after your meal.

In this stage, we are adding eggs to the list! Let’s see what else you can have:

  • Zucchini
  • Carrot
  • Potato
  • Sweet potato
  • Parsley
  • Green beans
  • Spinach
  • Chia seeds
  • Asparagus
  • Eggs
  • Soft and low-fat cheese
  • Purslane
  • Cooked and peeled tomato

You can eat vegetable purees mixed or separately. Let me remind you again: do not use potatoes and carrots constantly and do not consume too much of them if you are going to mix the veggies.

In the last 2-3 days of this stage, you can start trying to eat cheese. And on the last day, try mixing egg and cheese together. If you are having trouble tolerating it, try it again a week later.

On a side note, you may experience a halt during this stage. This means your weight loss will slow down or pause. This is called a bariatric plateau and it is absolutely normal. It will get back to normal in a short while.

Stage 4: Semi-pureed semi-solid diet

This stage is when you start eating lean meats and fish unless you’re following a vegan or vegetarian diet. Since you are not quite at the solid diet stage, they should be blended or mashed with a fork. You can also start eating raw fruits. Provided they are not citrus, are peeled, and are soft. This stage will last one week.

You can add some flavor to your food now! For instance, you can have your egg with 3 slices of peeled and cooked tomato. You can also add some spices to your protein shake! Cocoa powder, cinnamon powder, and sugar-free vanilla powder are some of the great options.

Here is the list of food you can have at this stage:

  • Lean meats – chicken, ground beef, turkey
  • Fish – low-fat tuna and other big fishes that are low in fat
  • Other seafood
  • Soft and peeled fruits except for citrus fruits– raw or cooked

You also need to make sure that you chew them well, especially ground beef. It is the hardest food for the stomach to digest. Regardless of what you are eating, you should help your stomach by starting the digestion in your mouth.

Stage 5: Solid diet

In this stage, we are going to try most of the foods that we are now allowed to consume. This way, we will see what we can tolerate and what still needs some time before we can have them. Do not try all the food all at once. We have plenty of time. We will try them one by one, day by day.

This stage will start after a month after your date of discharge. And it will usually last until the 3month checkpoint.

Let’s check the list of things you can now have:

  • Edamame
  • Brussel sprouts
  • Green peas
  • Cooked onion and garlic
  • Spices
  • Cauliflower
  • Broccoli
  • Lettuce

You may have noticed that you are now allowed to have vegetables that may make you gassy and, finally, spices. Make sure that you eat these foods slowly and give them time. Your stomach may not be able to tolerate them immediately.

Now, you can have meat without shredding or blending them. However, red meat is still a tough one to digest. So, you still need to have it as ground beef. And do not cook your meats and veggies together. It may disturb your stomach. While eating, eat your proteins (meats, yogurt, cheese) first, as it is more important.

You can still have soups. It is absolutely optional. However, you can have some soup 30 minutes after dinner. Because your protein intake should be your first priority and soup is also liquid.

Essential support: The role of water and supplements

Water is life. We all know it. Especially after surgery, you need to keep yourself hydrated to promote a healthy recovery. Keeping yourself hydrated will help you protect your skin and hair, and help heal the wounds from the surgery. Water also helps with blood circulation and helps the liver detox the body.

Because of the very small amounts of food you will be able to consume, as a side effect, you may experience nutritional deficiencies. To prevent and manage them, you will be recommended to take supplements. These supplements can be protein shakes and multivitamins.

Protein shakes can help lose fat instead of muscle while you are losing weight. It can also help the production of enzymes, hormones, and antibodies; indirectly boosting your metabolism.

Due to a lack of vitamins and minerals, you may feel tired, weak, and dizzy. You can also experience hair loss. To manage and prevent these from happening, you will be recommended to take multivitamins starting from your discharge from the hospital.

Why do you have to do it?

One of the reasons behind this diet program is to give the stomach time and rest it needs to heal. To aid that and promote healthy recovery for both physical and dietary, patients have to follow this diet after gastric sleeve.

This dietary program is also made for gastric sleeve patients to get their nutrients in moderate calories. Because weight loss surgery alone can help you lose weight to a certain point. After that is up to you to keep it under control.

What happens if you don't do it?

If the patient does not follow up with the gastric sleeve post op diet, their stomach can stretch again and they can regain the weight they lost.

For instance, if the patient eats solid food way before they were supposed to, or consumes food or drinks that they should not, that may eliminate the effects of gastric sleeve. For instance, if they eat foods or drinks they are not allowed to eat or eat solid food way before they should, weight gain might not be the only consequence.


(1) Tabesh MR, Maleklou F, Ejtehadi F, Alizadeh Z. Nutrition, Physical Activity, and Prescription of Supplements in Pre- and Post-bariatric Surgery Patients: a Practical Guideline. Obesity Surgery. 2019;29(10):3385-3400. doi: Link

(2) Gasmi A, Bjørklund G, Mujawdiya PK, et al. Micronutrients deficiences in patients after bariatric surgery. European Journal of Nutrition. 2021;61(1):55-67. doi: Link

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