VSG Diet: An Overview

VSG Diet: An Overview

If you have 100 or more pounds of weight to lose, you may consider the Sleeve Gastrectomy procedure. A type of weight loss surgery, the sleeve gastrectomy (VSG), or gastric sleeve, is a popular procedure for those unable to lose weight through other means. One thing you'll have to keep in mind after surgery is adherence to a VSG diet.

Although the gastric sleeve can be very effective in helping you to lose weight, the decision to undergo this procedure should not be taken lightly. This is because the surgery is permanent and requires a lifelong change in eating habits.

How does eating change after a gastric sleeve? In this article, we will take a look at the required short-term and long-term diet changes.

What is a sleeve gastrectomy?

Let’s start with a quick primer on the procedure itself. The sleeve gastrectomy involves removing part of the stomach, leaving behind a banana-shaped ‘sleeve.’

The intestines are not altered, and the new stomach is about 1/5th the size that it was. This changed anatomy physically restricts how much food the stomach can hold. Also, there are changes in hormones involved in appetite, making you feel less hungry.

Why are diet changes necessary after surgery?

Large amounts of food will not be well tolerated after surgery.

If you continue eating the same after the surgery, you will notice this will result in several unpleasant side effects. For starters, the stomach will not be able to handle an average amount of food and may signal the brain to induce vomiting Failure to follow the VSG diet guidelines can also delay the healing process after surgery and lead to stomach pain.

On top of these uncomfortable issues, the gastric sleeve diet is designed to keep your nutrition in check. Since you will be eating a much smaller number of calories, it requires more careful planning to make sure you are getting all the essential nutrients that your body needs.

Lastly, over time the stomach may stretch and allow for more calories, and if you are not careful, this can result in regain of lost weight; the last thing you want after undergoing an irreversible surgery!

The VSG diet is comprised of four distinct phases:

  1. Clear liquid diet
  2. Full fluid diet
  3. Soft foods
  4. Regular foods

In addition to the diet phases, you will be prescribed specific amounts of vitamin and mineral supplements.

VSG Diet Phase 1: Clear Liquid Diet

Clear fluids that are low in sugar is all that should be consumed in the first day or two after surgery.

Immediately following surgery, you will need to follow a clear liquid diet. This diet is typically used for only one or two days while still in the hospital. A clear liquid diet includes water, sugar-free flavored drinks, Jell-O, sports drinks, and broth. These drinks should be low in sugar and caffeine-free. This diet is not nutritionally adequate and only used as a transition.

After surgery, the stomach can only handle small amounts of fluid at one time, so small but frequent sips of water are recommended.

The clear liquid diet is effortless for the body to digest, and it helps to retrain the digestive system following surgery gradually.

VSG Diet Phase 2: Full Liquid Diet

Milk-based drinks and protein supplements are the main sources of protein at this phase.

After the clear liquid diet, you will transition to a full liquid diet for about two weeks.

The full liquid diet includes anything on the clear liquid diet with the addition of:

  • Skim milk
  • Soy milk
  • Unsweetened almond milk
  • Low-fat or nonfat yogurts
  • Shakes and protein powder without added sugar
  • Protein supplement drinks
  • Strained and smooth hot cereals such as cream of wheat
  • Thin soups and broths
  • Strained creamy soups

During this phase of the VSG diet, getting enough nutrition, especially protein, is very important. You will need about 70-80 grams of protein per day, but this may vary from person to person. Protein is required for surgical wounds to heal and to reduce the inflammation from the surgery.

Protein-packed supplements will be the primary source of protein during this stage. Be careful not to get too much protein at one serving, and the healing stomach can only handle so much at one time – spread out protein throughout the day,

Staying hydrated is another consideration; at the very least, 48-64 oz of fluid should be consumed.

VSG Diet Phase 3: Soft Diet

Start with pureed foods and then progress to soft textures.

At this point, you can slowly start to add some solid foods into the diet, starting with mostly pureed (mashed potato consistency) and gradually transitioning to moist, soft foods. The length of this phase varies from person to person, depending on individual tolerance.

When following the soft diet, the following rules should be kept in mind.

  • Start with protein: gradually introduce soft, pureed, or ground meats, beans, eggs, or other protein-containing foods multiple times per day.
  • Once protein is well-tolerated, try a few soft and moist vegetables and fruits. Applesauce, canned fruit, cooked green beans, and cooked carrots are good choices.
  • Lastly, starches can be added, such as cooked rice, cooked cereals, creamed corn, mashed potatoes.
  • Food groups should be eaten in order of priority: protein foods first, then fruits and vegetables, starches if there is still room.
  • Continue to aim for at least 48-64oz of fluid and 70-80g of protein. Protein supplements can still be used as needed.
  • Drink fluids 30 minutes before and after each meal (not during a meal).
  • Avoid frying foods.
  • Your dietitian should provide a detailed VSG diet meal plan; make sure to view this as part of your medicine. It is not optional.

VSG Diet Phase 4: Regular Diet

Nutrient-dense foods in small portions are key for long term success.

Finally, as the initial weight loss slows down and more foods are tolerated, it is time to graduate to the regular diet.

At this point, a larger variety of textures and types of food can be tried. Getting used to listening to your body will be vital during this VSG diet phase. Introduce one new food at a time, and continue to follow the recommended priority of foods as protein, fruits/vegetables,  starches.

Choose nutrient-dense foods as much as possible. These are foods that provide more nutrition bang for your buck, like eggs, poultry, lean meats, fish, whole fruits, vegetables, and whole grains. It is important to keep processed foods, sweets, and sugary beverages to a minimum to maintain weight loss and avoid digestive issues. In general, alcohol should be avoided, as well.

Make sure to eat slowly and eat 3-6 small meals per day. Portions of food should only be about 4-6 oz at a time. As before, keep liquids between meals and stay hydrated with at least 48-64 oz of fluids.


Going through with a sleeve gastrectomy procedure requires careful thought about the benefits and drawbacks. It is a good idea to ask yourself if you will be able to significantly alter your eating habits after surgery and maintain this new way of eating for the rest of your life. With patience, practice, and guidance from your medical team, you can have a successful outcome after surgery and maintain this progress for the long term.

Michael Fornaris, RD, CDE


Michael is a registered dietitian & diabetes educator currently working in outpatient nutrition counseling. He specializes in weight management, diabetes control, prediabetes, and metabolic syndrome.

Gintas Antanavicius, MD, FACS, FASMBS

Medical Reviewer

Dr. G is a co-founder of BariBuilder. A US-based expert surgeon with over 10 years of bariatric experience, he regularly publishes research in medical journals like SOARD, Obesity Surgery, etc.