Abstract
Introduction: Approximately $315 billion is spent annually on the medical cost of obesity in adult patients in the United States alone. According to the American Society for Metabolic and Bariatric Surgery (ASMBS), the rate of bariatric surgery (BS) increased from 158,000 in 2011 to 196,000 in 2015. This increase in invasive techniques does not eliminate unhealthy habits, therefore, lifestyle modifications, such as healthy eating and correct physical activity programs, can improve surgical results. Objective: To establish the main nutritional and metabolic management strategies in the context of bariatric surgery, to modulate and reduce the problems caused by nutrient deficit. Methods: The systematic review rules of the PRISMA Platform were followed. The search was conducted from May to June 2024 in the Web of Science, Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 135 articles were found. 42 articles were fully evaluated and 18 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 22 studies with a high risk of bias and 24 that did not meet GRADE and AMSTAR-2. Most studies presented homogeneity in their results, with X2=79.7%>50%. It was concluded that the recommendations were gathered to assist in individualized clinical practice in the nutritional management of patients with obesity. In general, patients with obesity have significantly lower concentrations of serum iron, folic acid, vitamins A, B6, B12, C, 25-hydroxyvitamin D, and lipid-standardized vitamin E. Before bariatric surgery, nutritional status should be analyzed and preoperative weight loss can be attempted. Very low-calorie diets and very low-calorie ketogenic diets are prescribed in the last months before surgery. It was noted that the recommendations were gathered to assist in individualized clinical practice in the nutritional management of patients with obesity, including nutritional management. Iron status may be affected by adipose tissue inflammation and increased expression of the systemic iron regulatory protein hepcidin. The postoperative recommendation for vitamin B12 (cobalamin) should be 350-500 micrograms/1000 micrograms monthly, and for folate (folic acid) in the postoperative period should be 1000 micrograms per day.