ABSTRACT
Food serves a number of requirements of the body. Each of the three main food groups (macronutrients), carbohydrates, proteins and fats, provides energy. In addition, food provides the body with a variety of other nutrients. Proteins provide the key building blocks of tissues, amino acids, some of which cannot be synthesised by the body. Fats (in general, lipids) are also important in numerous physiological processes and some fats, the essential (atty acids, cannot be synthesised in the body. Most vitamins, and all of the minerals that are essential for the proper functioning of the body, must be ingested in the diet. By the process of digestion food is broken down mechanically and chemically into simpler substances that are absorbed from the small intestines and used by the cells of the body.
