This module explores the role of nutrition in cancer prevention, treatment, recovery, and supportive care, with emphasis on metabolic changes and treatment-related nutritional challenges. It covers cancer metabolism, including the Warburg effect, muscle loss, cachexia, and the impact of chemotherapy, radiation, and surgery on nutritional status. The module provides practical strategies for managing symptoms such as nausea, mucositis, taste changes, early satiety, diarrhea, constipation, and reduced appetite through individualized dietary interventions. Emphasis is placed on evidence-based medical nutrition therapy, adequate protein and energy intake, and appropriate use of enteral or parenteral nutrition when oral intake is insufficient.