Bariatric surgery is characterized by a surgical intervention for the treatment of obesity, in which the digestive system is altered in order to reduce the amount of food tolerated. Individuals who choose this line of treatment considerably reduce their food intake, which promotes rapid weight loss. This rapid loss is the main reason for the significant increase in demand for bariatric surgery over the last decade.
Although bariatric surgery is the most successful method for weight loss, for true complete success certain steps need to be ensured with the help of a multidisciplinary team.
One of the elements in the team is the nutritionist, who plays an important role from the pre-surgery stage and throughout post-surgery. In a first stage, the nutritionist assesses the patient’s eating habits and clarifies all questions about what care should be taken at the time following surgery. It is also worth noting that before surgery, after evaluation by the surgeon, it may be necessary to implement a food plan reduced in calories and carbohydrates in order to promote a decrease in the volume of the patient’s liver, favouring a less invasive and shorter surgery.
After the intervention it is necessary to start a liquid diet program with limited volume at each meal during the first few weeks. These guidelines are changed throughout the following months, where there is a smooth transition to the slurries, followed by soft and finally solid food. Meal volumes will also be altered, always taking into account the indications as well as the well-being reported by the patient. Therefore, the need for follow-up with the nutritionist is imperative to ensure a quick and healthy recovery.
Since there is a marked reduction in food intake, and surgery causes a change in the morphology of the gastrointestinal tract, the absorption of macronutrients and micronutrients is compromised especially at an early stage. One of the main challenges is the inclusion of the necessary dose of protein in the patient’s post-surgery diet. Recent studies show that a high number of individuals who resort to bariatric surgery do not ingest the necessary amount of protein. This is one factor that impairs the maintaining of muscle mass during the weight loss process, even though the correct protein intake generates lack of hunger favouring of course weight loss.
In addition to the amount of protein, carbohydrate intake should be taken into account. These are the main source of energy for the human body. As such, although food intake decreases sharply, there is a minimum amount of carbohydrates to be guaranteed on a daily basis, in order to preserve brain function as well as muscle function.
At consultation, through the regular assessment of the nutritional status, the nutritionist provides a food plan adapted to each moment, so that the patient can meet the nutritional needs after the surgery.
Regarding micronutrients, studies claim that there is an increase in nutritional deficits as the monitoring by health professionals decreases. Nutritional status should be evaluated before and after surgery, and the main nutrients to be taken into account are: vitamin B12, vitamin B1, folic acid, vitamin A, vitamin E, vitamin K, vitamin D, iron, calcium, copper and zinc.
In short, even though bariatric surgery is a valid option when it comes to weight loss, it does not eliminate the need for patients to improve their lifestyle. Although food intake is initially lower, in the long term tolerance may increase. With the help of a nutritionist, patients must implement healthy eating habits as well as the practice of regular physical activity, so that surgical success is maintained in the long term.
Dra. Carolina Alves