Patient Resources

Dietary phases after surgery

After an obesity operation, a progressive diet of adaptation is necessary.

Always start with a liquid diet, about 10 days long and that is essential to allow the recovery of the stomach. From then on, the patient must learn to eat correctly, with good chewing, without rushing and making a conscious act out of the food, in this section we inform you of each of the dietary phases to be taken into account after an obesity surgery and the advice to achieve it.

  • Duration: 10 days.
  • Introduction of food: isotonic liquids, juices without added sugar, infusions, milk, vegetable drinks without added sugar, liquid yoghurt, defatted or vegetable broths.
  • Nutritional supplement: 2 protein shakes a day.
  • Duration: 7 days.
  • Introduction of foods: natural yoghurt, broths with semolina or tapioca, liquid vegetable creams with crushed animal protein (chicken, turkey, fish, egg, cheese, etc.).
  • Nutritional supplement: 36g a day of soy protein supplement, divided into 3 intakes.
  • Duration: 7 days.
  • Introduction of foods: more consistent purees of vegetables with animal protein, fruit puree or compote, roasted apple or pear, breakfast cereals without added sugar, oat flakes, puffy rice/spelt/centene flakes, gelatines.
  • Nutritional supplement: 36g a day of soy protein supplement, divided into 3 intakes.
  • Duration: 7 days.
  • Introduction of foods: cheese, uncrushed but cooked vegetables (not salads), toasted bread or biscuits, boiled potato, broth rice, well-made pasta, whole ripe fruit, egg, fish, minced or stewed meats, lean cold cuts.
  • Nutritional supplement: 36g a day of soy protein supplement, divided into 3 intakes.
  • Duration: Healthy eating that you should follow throughout your life.
  • Foods included in addition to the above: salads, legumes, natural fruit, raw or roasted nuts without salt (not fried), and other foods not included above.
  • Eat slowly, on a dessert plate and not "force".

What are proteins?

Proteins are nutrients that are found in certain foods and that mainly perform a structural function in our body, or what is the same, are responsible for forming and maintaining muscle mass. They also play other roles in our body, acting as transporters of substances or as part of other structures of vital importance. You can read more about proteins and in which foods we can find them in our section "Contribution of proteins in the diet, after an obesity operation".

Importance of proteins in an obesity operation

Several scientific studies support the importance of adequate protein intake, both before and after surgery, to achieve optimal recovery.
In our pre and post-operative action protocol, we take into account the importance of this macronutrient and therefore prevent a deficit from occurring through an adequate supply of proteins.
However, due to the fact that this is an operation that modifies the physiology of the stomach and therefore its function, we cannot provide the protein in a natural way in all phases, since they would generate a heavy and contraindicated digestion after an obesity operation or they would form residues at intestinal level if consumed before the intervention.

Protein shakes for assured nutritional support

The solution to this problem is to provide proteins by means of liquid shakes. These proteins are obtained by isolating and purifying products mainly from milk and eggs. Therefore, we can consider that the origin of the proteins contained in these shakes is natural, but with a basic difference, that in a much smaller amount of liquid, we get a much higher concentration of proteins than if we drank milk alone for example.
But there is one detail that must differentiate the rest of protein shakes. It is not enough that they contain proteins, but it is also essential that they are rich in all vitamins and minerals, that they contain slow absorbing sugars, lipids and fibre. The reason for this is that if we only provide protein but leave aside the rest of nutrients the deficit eventually appears.
The shakes we use in our clinic contain all the elements mentioned above in the proportions necessary so that they can be temporary substitutes for food without generating any nutritional deficit due to a lack of any essential nutrient.

Diet progressivity

In our preoperative protocol, we establish a completely liquid diet that has a variable duration depending on the surgical technique and the BMI and pathological characteristics of each patient. During this preoperative diet the patient can only consume liquids such as juices without added sugars, infusions and of course the milkshake. How we can check the shake will be responsible for providing all essential nutrients, including proteins during this liquid phase so it cannot be missing in the preoperative diet.
Following the protocol and after the intervention, the patient must progressively introduce the food in order not to cause unnecessary stress to his organism and to check the good digestion and acceptability of each of the foods he consumes again. To do this, it begins with a completely liquid diet similar to the preoperative and over time, adding new textures and types of food until a month and a half after surgery, a completely normal diet.
But during the first 20 days approximately, the contribution of proteins, vitamins, minerals, fibber and essential fatty acids, is diminished as a consequence of not being able to contribute solid foods yet (Meats; Fish; Eggs; Legumes...). This is where complete protein shakes continue to play a very important role and therefore their consumption cannot be neglected, since an optimal recovery after the intervention and a good food adaptation depend on them. In addition, they allow there to be no loss of muscle mass during weight loss, thus favouring that the weight loss is mainly fat mass.


Therefore, we must always remember that:1- Protein-rich shakes are essential before and after a stomach operation2- In addition to proteins, these shakes must contain all the essential nutrients for proper functioning of our body and to avoid deficits3- They allow optimal recovery of both surgical wounds and physical condition in general4- They encourage the development and maintenance of muscle mass during rapid weight loss5- The total amount of protein must be controlled in each particular situation, since each person has different requirements. Never make decisions of your own free will without first consulting our multidisciplinary team.