Role of Oral Nutritional Supplements in Minimizing the Risk of Postoperative Malnutrition in Patients Undergoing Gastrointestinal Surgery

Background/Objectives: Perioperative fasting combined with procedure-related trauma increases the risk of malnutrition and determines the treatment outcomes of surgical patients. The aim of this study was to assess the range of metabolic deficiencies and the effectiveness of oral nutritional supplements (ONSs) after surgical intervention. Methods: 84 patients undergoing elective abdominal surgery were included in this study. Patients were divided into three groups: receiving a low-osmotic ONS (Group I), high-osmotic ONS (Group II), and Group III, who did not receive any oral supplementation. The clinical assessment involved body weight measurements and metabolic blood tests preoperatively and on the 4th, 7th, 14th, and 28th postoperative days. Results: The mean blood levels of total protein, albumin, cholesterol, and blood lymphocyte count decreased in the first 4 days after surgery and returned to baseline between 7 and 14 days. Similarly, BMI dropped during the first two weeks and then stabilized or returned to pre-surgery values. Triglycerides initially increased and, after 14 days, started to normalize. Patients receiving an ONS compensated quicker than the control group and more efficiently with low-osmotic supplements. Conclusions: Surgical trauma is associated with metabolic deficiency. The early administration of ONSs provides significant benefits to patients undergoing abdominal surgery. Low-osmotic supplements are especially recommended due to better tolerance.