This document discusses food and nutrients. It defines food as any substance that can provide nutrients to the body. Nutrients are chemical substances that help the body stay healthy and energetic. There are five main types of nutrients: carbohydrates, proteins, fats, vitamins, and mineral salts. Carbohydrates, proteins and fats provide energy, while all nutrients have roles in growth, repair, and regulation of functions. A balanced diet containing all nutrients is essential for health.