Preoperative Nutrition in Bariatric Surgery: A Narrative Review on Enhancing Surgical Success and Patient Outcomes

Abstract

Bariatric surgery has become the preferred treatment for individuals with morbid obesity. Nutrition is key in optimizing surgical outcomes by reducing risks and enhancing recovery. Preoperative strategies, such as reducing body fat, decreasing liver size, and improving metabolic profiles, have been shown to facilitate safer surgical procedures with fewer complications. This narrative review aims to provide an analysis of the fundamental role of preoperative nutritional management in improving bariatric surgery outcomes, emphasizing the importance of addressing specific nutritional challenges to enhance surgical safety, recovery, and overall health. Preoperative nutritional interventions focus on correcting comorbidities and nutritional deficiencies, particularly hypovitaminosis and micronutrient imbalances, through a multidisciplinary approach involving nutritionists and other healthcare professionals. These interventions not only prepare patients for the physiological demands of surgery but also initiate a period of adaptation to new dietary habits, aiming to improve long-term compliance and mitigate risks such as postoperative weight regain and dumping syndrome. Adopting dietary changes, such as very low-calorie or ketogenic diets 6-12 weeks before surgery, enhances adherence to postoperative restrictions and overall surgical success. Future research should focus on developing comprehensive guidelines for preoperative nutritional care to improve patient outcomes globally.

Keywords: bariatric surgery; healthcare; micronutrient supplementation; obesity; preoperative micronutrient deficiencies.

Figure 1

Options to assess nutritional status in patients: To assess nutritional status, it is essential to combine the analysis of biochemical markers (such as albumin, transferrin, and serum zinc) with the use of screening tools, such as the Mini Nutritional Assessment (MNA) and Global Leadership Initiative on Malnutrition (GLIM) criteria. This combined approach enables the identification of malnutrition risks and facilitates targeted clinical interventions [20,23,60,61,62,63,64,65,66,67].

Figure 2

Preoperative preparation and nutritional interventions in bariatric surgery. The preoperative preparation for BS includes six stages: initial evaluation of medical and dietary history to identify comorbidities and deficiencies; biochemical testing to assess levels of vitamin D, iron, B12, folate, proteins, and other micronutrients; correction of deficiencies with tailored supplementation; implementation of preoperative diets such as VLEKT to reduce liver size and weight; transition to a liquid diet 24 h before surgery with clear liquids and protein shakes; and a final review to confirm nutritional correction and psychological readiness [5,119,120,126].