The bariatric diet – stages of diet after surgical treatment of obesity

Following a strict diet after surgical treatment of obesity is one the basic rules in order to fully achieve and enjoy the effects of the operation. Reducing the stomach volume significantly affects the amount of food consumed by the patient, so the type and nutritional value of products is very important for the process of losing excess weight and general health and well-being. Dietary recommendations are tailored individually to the patient and they often depend on the type of bariatric surgery they underwent. Which products can be eaten before and after surgical treatment of obesity?

Dietary advice is tailored individually to the patient and it often depends on the type of bariatric surgery they underwent. Which products can be eaten after surgical treatment of obesity?

Diet before bariatric surgery

A proper diet is a key factor not only after but also before bariatric surgery. During the preparation period, it is recommended that the patient switches to a low-calorie diet in order to improve the liver wellness. Such recommendation is important because of the much higher risk of complications with surgery when the patient’s liver is enlarged due to large stores of glycogen, water and fat.

The earlier the patient goes on a low-calorie diet (800 to 1000 kcal per day), the greater the chance that the size of the liver will decrease, giving better access to the stomach during bariatric surgery. It is important to ensure that meals before surgery are low-fat, low-carbohydrate and that at least 15 to 20 percent of energy components come from protein. Before bariatric surgery the patient should drink a minimum of 2 litres of fluids per day at regular intervals throughout the day.

5-7 days before the surgery, an entirely liquid diet should be started. Prepared meals should be eaten slowly and at ease at equal intervals. After eating a liquid meal, it is necessary to wait at least 30 minutes before drinking any liquids, so that the food has time to be absorbed and is not further diluted with drinks. All this aims to prepare the stomach for the procedure.

The first two days after bariatric surgery

During the entire process of surgical treatment of obesity, an extremely important factor is an appropriate hydration of the body. For two days after bariatric surgery the patient is given not only drips, but also liquids, which at this stage the patient can drink on his own. The best choice is still mineral water or weak tea, in portions of 30-50 ml at a time. There is no direct limit to the amount of liquids consumed per day, but there must be breaks between each serving and the patient has to drink slowly, calmly, without swallowing air.

The bariatric diet until the second week after the operation

After the first two days, the body of the person who underwent the operation begins to gradually recover, allowing the introduction of the first nutritional drinks. Products such as drinkable yogurt, blended soups and broths, unsweetened fruit and vegetable juices diluted with water appear in the bariatric diet until 2 weeks after surgery. Skimmed cow’s or vegetable milk is also acceptable. However, it should be remembered that each product will depend on the individual reaction of the patient’s body and some may not be acceptable in the first few days after their introduction. For this reason, it is important to carefully observe the body’s reaction and check whether these products are definitely advisable in a given case.

Diet until the fourth week after the operation

In the next weeks following the operation, the amount of neutral liquids is gradually increased, including water and light tea, as well liquids such as drinking yoghurt or blended soup. In addition, it is possible to gradually replace liquid foods with soft solid foods that are high in protein and low in fat.
Products should continue to be given without pieces of solid food – it is permissible to give lean minced meat, mashed potatoes, fish, yoghurt, quark, eggs as well as soft fruit and vegetables without skin. The habit of chewing and eating slowly can be taught thanks to the use of a pap – although this task seems obvious, it is often problematic for overweight patients.

In practice, the slower the food is eaten and the longer it is chewed, the lower the risk of nausea and vomiting and the quicker it is possible to achieve a feeling of satiety without over-stuffing the stomach. The size of a portion of pap should preferably not exceed 50g per serving, unless otherwise recommended by the doctor. Eating light meals without hurrying should eliminate problems with vomiting and a feeling of heaviness in the stomach. However, if there are disturbing symptoms, it is important to consider whether the patient has followed all the rules and answer the basic questions:

• Have I eaten the entire portion too quickly?
• Have I chewed the meal well?
• Have I eaten too much?
• Have I had a fluid too quickly after the meal?
• Have I gone to bed too soon after finishing my meal?

If the answers to all of these questions are in line with the doctor’s advice, and the patient still experiences nausea, it is worth consulting the GP to find out whether any additional dietary changes are necessary.

Up to six weeks after surgery – first solid foods

At least one month after the operation, the patient should be ready to eat first solid food. These must still be soft foods that are easy to crush with a fork, but they can be more varied than before. 

It is allowed to eat soft fresh fruit, minced or finely chopped meat and cooked vegetables. The basis of meals should still be the high-protein products served in each dish first – meat, eggs or fish is the appropriate choice. All meals should provide a total of circa 60-80g of protein per day.

Permanent bariatric diet – how to eat after surgical treatment for obesity?

Bariatric surgery changes the way a person which suffers from obesity can eat. After completing all previous dietary steps, the patient can slowly move to a solid diet, with further foods introduced one at a time. 

The goal of the diet is to limit the intake of simple sugars and fats; the diet is low in calories and consists of small meals taken 5 to 8 times a day. The size of a single meal is usually between 50 and 150 grams, depending on the body’s tolerance. The patient’s menu should always consist of high protein products, vegetables, fruits, 2-3 cereal products and 2-4 servings of good quality vegetable fats. 

Among the forbidden foods on the bariatric diet are nuts and seeds, roasted corn, dried fruits, vegetables such as celery, broccoli, corn or cabbage, fatty meat and offal, fresh bread, mushroom, fried foods, fatty dairy products, spices, alcohol and sweets as well as fast food. 

The bariatric diet should be based on a systematic approach and healthy, high-quality products that provide the right amount of nutrients to the body. The patient should eat small portions and must not overeat. A key factor is also keeping regular intervals between meals and avoiding drinks for at least 30 minutes after a meal. It is important to drink about 2 litres of fluids throughout the day and to avoid unhealthy foods such as sweets, fast food and fizzy drinks. Eating snacks between meals should also be avoided.