NIMA-Colon Cancer Study

The goal of this study is to evaluate the effects of nutritional supplementation and physical activity interventions on recovery, muscle strength, nutritional status, inflammation, and metabolic health in adults with colon cancer undergoing surgery. Patients with colon cancer frequently experience loss of muscle mass, reduced physical function, and nutritional deterioration both before and after surgery, which may adversely affect recovery and quality of life. A key objective of this study is to assess whether a postoperative intervention combining nutritional supplementation with beta-hydroxy beta-methylbutyrate (HMB) and vitamin D, together with a structured physical activity program, can improve muscle strength and functional recovery following colon cancer surgery. This study aims to answer the following questions: * Does nutritional supplementation with HMB and vitamin D, combined with postoperative physical activity, improve muscle strength and physical function following colon cancer surgery? * How do nutritional and lifestyle interventions influence nutritional status, gut microbiota composition, and biological markers of inflammation and metabolism during the recovery period? * Are there differences in recovery outcomes between patients receiving different types of nutritional support, with or without supervised physical activity? Participants will be adults diagnosed with colon cancer who undergo surgical treatment at the Hospital Universitario Virgen de la Victoria in Málaga, Spain. Patients will be recruited prior to surgery and will enter a prehabilitation phase integrated into routine care provided by the Endocrinology and Nutrition Department. During this prehabilitation phase, nutritional status will be assessed and optimized using standard clinical care, including oral nutritional supplementation when indicated. The aim is to improve the patient's condition before surgery. Approximately one month after surgery, once initial postoperative recovery has been completed, participants will enter the intervention and assessment phase (baseline visit). Participants will then be randomly assigned to one of four study groups in a 2×2 factorial design. These groups combine two nutritional strategies (standard care or supplementation with HMB and vitamin D) and two physical activity approaches (supervised exercise or general activity recommendations). The physical activity component, supervised by the Endocrinology and Nutrition team, will be objectively evaluated using an accelerometer-based device. Participants will be followed for approximately six months, with assessments at about 3 and 6 months after the baseline visit. At each visit, participants will undergo: * Body composition measurements * Muscle strength and physical performance tests * Collection of blood, urine, and stool samples * Questionnaires on health status and quality of life The results of this study will contribute to a more profound understanding of how tailored nutritional strategies and postoperative physical activity may support recovery and functional health in patients undergoing surgery for colon cancer.