Bariatric and metabolic surgery aims to improve the quality of life of obese patients through the promotion and maintenance of programmed weight loss. It is impossible to treat obesity without an efficient and integrated performance of a team of specialists.

Clinical nutrition comes to improve this process. And stupefy! This process begins even before the surgery itself. It is important to have corrections of possible nutritional deficiencies present in the preoperative period, to correct bad eating habits, to establish a routine of behavioral adaptations, to reduce surgical risk through weight loss and to discuss with the patient and his family the changes that will occur in the post-operative period.

After bariatric surgery, the anatomy of those who will become an ex-obese will be altered: the stomach will have been reduced to a gastric capacity of 50ml and part of the intestine will have been excluded from the alimentary path. All this, aiming to promote a weight loss through the restriction of food intake and nutrients to be absorbed. Therefore, it is important that we help our patients to make better choices of food, to know how to evolve from different food consistency in order to maintain the integrity of surgical staples and to supplement nutrients adequately (orally, intravenously or intramuscularly) that, as we know from clinical practice and review of literature, will be depleted over the time.

In this way, nutritional monitoring will seek the physical and emotional well-being of our patient, through the selection of foods that contain the healthiest nutrients and that are adapted to the needs of each individual so that the rapid weight loss does not lead to malnutrition or to fearsome weight regain, if the patient does not understand from before operating, that the scalpel does not do miracle by itself.
In general, the main change in food intake after surgery is a significant decrease in the amount of food consumed daily due to the stomach reduction. However, other care about food intake is essential. The care can be divided into five phases after surgery:

1st stage - liquid feeding phase: this phase comprises the first two weeks after surgery and is characterized as being an adaptation phase. The food is liquid and consists of small volumes (around 50 ml every 30-minute period) and its main objectives are gastric rest, adaptation to small volumes and hydration.

2nd stage - consistency evolution phase: according to the tolerance and individual needs, food goes from liquid to pureed food with the introduction of liquefied preparations, creams, and thin pap. The evolution of each patient is variable so that the choice of each food should be carefully monitored to avoid digestive discomfort such as pain, nausea and vomiting. This phase has a different duration time for each patient. However, on average, it lasts around 02 weeks.

3rd stage - qualitative selection and exhaustive chewing phase: elapsed the first month after surgery, a phase begins where food selection is of fundamental importance since considering that the quantities ingested daily are still very small, preference should be given to more nutritious foods by choosing sources of protein, iron, calcium, and vitamins daily. The duration of this phase also varies individually and lasts on average 01 month.

4th stage - phase of the optimization of the diet: in this phase, the diet gradually evolves to a consistency closer to the ideal for a satisfactory nutrition. Generally, this phase occurs from the 3rd month after surgery, when almost all foods begin to be introduced into the daily diet. The care with the choice of nutritious foods must continue because the quantities ingested daily are still small. At this stage, the patient may be able to select the foods that bring him more comfort, satisfaction, and nutritional quality.

5th stage - final adaptation phase and food independence: this phase should start at the 4th month and accompany the patient and, as in the previous phases, also evolves according to the individual characteristics and might start a little before or a little after the 4th month. From this phase on, periodic follow-up is necessary only for monitoring weight evolution and gathering information to identify if there are any nutritional deficiencies, such as anemia. The patient has already enough safety in the choice of food and is able to understand which foods are rich in proteins, carbohydrates and lipids, calcium, iron, vitamin A, vitamin C, folates plus other nutritional properties.

SOME IMPORTANT FEATURES

THE INGESTION OF LIQUIDS.
Rapid weight loss leads to a transient increase in uric acid levels in the circulation. When hydration is not sufficient, renal lithiasis (kidney stones) may form. For this reason, the consumption of liquids must be monitored to avoid that the urine becomes very concentrated. Should you ingest liquids even if you are not thirsty? No doubt. The ingestion of liquids must be constant, independently of the thirst.

THE CHOICE OF FOOD HIGH IN IRON.
Red meat is among the most fibrous foods and which acceptance takes more time. While meat is not introduced in the diet, the nutritionist should advise the patient about other sources of iron present in the food.

SUGAR INTOLERANCE.
The consumption of sugary foods should be avoided for two reasons: First, because the caloric value is high and, second, depending on the surgical technique, there may occur Dumping Syndrome. An assessment of sugar tolerance may be performed since it is carefully monitored by the nutritionist. May a small amount of sugar intake lead to Dumping Syndrome? In the case of Capella surgery, yes, it may. Although it is not common, sometimes the consumption of just one candy can trigger the process.

WEIGHT LOSS RHYTHM.
Weight loss is very intense, especially during the first two weeks after surgery. The accelerated rate of weight loss continues to be observed until the third month and thereafter slows down. This is a natural process of physiological adaptation that causes the body to spend less energy daily to prevent that the rapid and permanent weight loss leads to malnutrition and consequent health risks such as the decline in resistance to infections, bone demineralization, among others. Is there any way to improve the pace of weight loss at this stage? The best way, besides persisting in nutritional guidelines, is to perform regular physical activity. Exercise causes the body to expend more energy, which helps to lose weight, in addition to bringing a sense of well-being and relaxation.

THE NEED FOR THE USE OF MINERAL AND VITAMIN COMPLEMENTS.
Whenever calories are substantially reduced from the diet, it is necessary to supplement vitamins and minerals. In the case of bariatric surgery, the caloric value of the food intake approaches 350 kcal in the first weeks and continues below 1000 kcal at least until the sixth month after the beginning of the treatment. Especially during this period, the supplementation is indispensable. This should be done orally and/or intravenously. Can supplements make you fat? No, they can’t. Vitamins and minerals do not produce calories. What gets fat is pizza, ice cream, and donut.