In fact, the European Society for Clinical Nutrition and Metabolism guidelines advocate for nutritional therapy in the 7–10 days leading up to surgery if at least one of the following criteria applies: (1) if a patient has experienced weight loss exceeding 10–15% within the last 6 months; (2) when BMI falls below 18.5 kg/m2; (3) if the patient is graded as subjective global assessment grade C; (4) when the nutritional risk screening score exceeds 5; and (5) if the preoperative serum albumin level is less than 3 g/L (provided there is no evidence of hepatic or renal failure) [23]. This evidence concerns the gene ALB and kidney failure.