Precise nutrition in the metabolic and nutritional management of bariatric surgery: a systematic review

Introduction: Obesity is a chronic relapsing disease characterized by abnormal or excessive adiposity with health risks. Any nutritional intervention in patients who are candidates for or have already undergone bariatric surgery must be based on a detailed nutritional assessment, including an assessment of personal values, preferences, and social determinants of eating habits. Objective: It was to carry out a systematic review to explore and present nutritional importance before, during, and after bariatric surgery. Methods: The PRISMA Platform systematic review rules were followed. The research was carried out from September to October 2023 in the 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: 122 articles were found. A total of 43 articles were evaluated in full and 34 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 26 studies that did not meet GRADE and AMSTAR-2. Most studies showed homogeneity in their results, with X2=64.5%>50%. It was concluded that enteral nutrition strategies could represent a possible alternative to other methodologies, especially when it is recommended to improve patient adherence to the diet prescribed before bariatric surgery. Weight loss induced by the ketogenic diet before bariatric surgery has beneficial effects in reducing liver volume, metabolic profile, and intra- and postoperative complications. Knowledge of the type of bariatric surgery performed and an understanding of its anatomy and physiology help provide optimal care to patients, especially nutritional complications. Nutritional deficiencies and metabolic disorders result from “malabsorption” procedures, such as RYGB. It is essential to immediately administer thiamine. Dextrose should be avoided in intravenous hydration until thiamine is adequately replaced. For all bariatric patients, a protein intake of 60-70 g/d and multivitamin with iron and vitamin B12 supplementation is recommended. Daily calcium and vitamin D supplementation is also encouraged. Additionally, serum micronutrient levels should be monitored regularly and additional supplemental measures prescribed as indicated.