Advances in Perioperative Nutritional Management in Metabolic and Bariatric Surgery.

Metabolic and Bariatric Surgery (MBS) is an effective treatment for severe obesity and its related complications. However, perioperative nutritional management is essential for the patient's surgical outcome and postoperative recovery. This article reviews the research progress in perioperative nutritional management of MBS. Preoperative nutritional assessment and optimization are essential, including monitoring and correction of micronutrient deficiencies, such as vitamin D, iron, folic acid, to reduce the risk of postoperative complications. In terms of preoperative dietary management, the use of a low-carbohydrate ketogenic diet (LCKD) and ready-to-eat low-carbohydrate ketogenic product (RLCKP) showed the potential to promote weight loss and liver volume reduction, creating favorable conditions for surgery. Strategies for preoperative weight loss (WL) need to be cautious, and moderate preoperative WL may help to reduce surgical difficulty and postoperative complications. In addition, the application of preoperative carbohydrate load can reduce postoperative insulin resistance and protein loss and promote postoperative recovery of patients. In terms of postoperative nutritional management, the risk of postoperative micronutrient deficiency is significantly increased. At the same time, the adjustment of postoperative dietary structure and rational use of nutritional supplements are important to maintain the nutritional status of patients and promote weight management. In conclusion, perioperative nutritional management of MBS is a multifaceted and multi-level comprehensive process that requires a multidisciplinary approach involving medical staff, dietitians, and patients. A tailor-made approach based on the patient's unique characteristics, such as nutritional status, surgical type, and personal preferences, is essential to achieve the best surgical results and improvement of patients' quality of life. Major challenges remain in perioperative nutritional management, such as the high prevalence of preoperative malnutrition and the complexity of postoperative nutritional deficiencies. In the future, more accurate preoperative nutritional assessment tools and personalized postoperative nutritional supplementation strategies should be developed.