How many calories should I eat after gastric sleeve surgery?

In this short article, we will answer the question “How many calories should I eat after gastric sleeve surgery?” and will discuss the nuances and recommendations for the diet after the surgery.

How many calories should I eat after gastric sleeve surgery?

In the case of gastric sleeve surgery, the caloric value of food should approach 350 kcal in the first weeks and remain below 1250 kcal at least until the sixth month after the surgery.

Especially during this period, supplementation is indispensable. Vitamins and minerals don’t produce calories, so they don’t make you get weight. Nutritional guidance should be instructed by the doctor and nutritionist, before the hospital discharge.

How is the diet after gastric sleeve surgery?

  First and foremost, we must remember that the food at this time is meant to aid in the stomach’s healing process as well as weight loss.  Five phases can be distinguished in the evolution of the diet in the first month after gastric sleeve surgery. They are:

  • Liquid diet
  • Consistency evolution;
  • Qualitative selection and thorough chewing;
  • Feed optimisation;
  • Final adaptation and food independence

Liquid phase

The liquid feeding phase lasts for the first two weeks and has as its goals adaptation to small amounts, hydration, healing, and stomach rest. To prevent complications, the first few days of post-surgery nutrition should be closely adhered to.  

Small amounts of liquid food—roughly 50 ml per serving—are included in each serving.

Water, coconut water, isotonic beverages, teas, strained natural fruit juices, strained vegetable broth, and diet gelatin are all considered acceptable foods. For about five days, dairy, sugar, and other fats are prohibited from the diet.

Due to this diet, there is a significant weight loss throughout these two weeks. To prevent vitamin and mineral shortages, specialized nutritional supplements should be administered.

For preparing food at home:

  • Prefer to make their own food rather than purchasing processed foods like soups and powdered juices.
  • Avoid liquid manufactured juices with colours and preservatives and always dilute them.
  • As always, season the broths, but don’t forget to drain.
  • When blending fruit, milk and yoghurt should also be filtered.
  • Drinks that are high in calories should be avoided. Examples include milkshakes, condensed milk, cream, ice cream, flans, puddings, and chocolates. They contain a lot of sugar and may result in dumping syndrome.
  • Avoid drinking alcoholic beverages.
  • Meals should be consumed slowly and may take up to 40 minutes to completely digest without experiencing any tummy pain.
  • At this point, the manner of food intake—that is, the rate and amount of food consumed—requires special attention.


Pay attention to how your urine looks because if it’s black, it could be the first indicator of dehydration. Uric acid levels in the blood briefly rise as a result of rapid weight reduction. Kidney stones can develop when there is insufficient water. 

Because of this, it’s important to keep an eye on your fluid intake to avoid having too much-concentrated urine. Regardless of whether you are thirsty, you should always drink fluids.

Foods to avoid for the first three months following surgery include:

  • Coffee, 
  • fried foods, 
  • mate tea, 
  • alcoholic beverages, 
  • green tea, 
  • pepper, 
  • sugars (chocolate, chewing gum, sweets in general), 
  • industrialized powdered juices, 
  • soft drinks, 
  • chemical condiments, 
  • milk and cow derivatives,  
  • carbohydrates (in excess), 
  • tobacco and carbonated water.

The phase of consistency evolution

Beginning in the second fortnight following surgery, the meal changes from liquid to pasty depending on tolerance and individual needs. The introduction of liquid preparations, creams, and thin infant meals starts in this situation.

Each patient’s course of treatment is unique, therefore it is important to choose foods carefully to prevent digestive problems like pain, nausea, and vomiting. While the length of this period varies from person to person, on average it lasts about two weeks.

Protein supplementation

In the postoperative period of bariatric surgery, protein supplementation can be a great ally in this postoperative period. 

It guarantees protein intake and consumption of ideal vitamins and minerals to ensure a balanced and healthy recovery, without interfering with the process of readaptation of the digestive and absorptive tract.


In this short article, we have answered the question “How many calories should I eat after gastric sleeve surgery?” and discussed the nuances and recommendations for the diet after the surgery.