This document provides information on diet therapy and protein energy malnutrition. It discusses the objectives and principles of diet therapy, including using food to treat diseases by changing a patient's normal diet based on their condition. It also covers the classification, causes, risk factors, complications, and treatment of protein energy malnutrition, specifically marasmus and kwashiorkor. The key differences between marasmus and kwashiorkor are outlined. Prevention and management of PEM focuses on proper nutrition, hygiene, breastfeeding, and treating underlying infections.