Dietary Nutrition: Food and Its Determinants
Food is any material consumed to supply nutritional support to an organism. In the human body, food is generally of animal, plant or microbial origin, and includes various nutrients, including proteins, fats, carbohydrates, vitamins, or other trace elements. The term ‘food’ is often used in association with the word ‘nutritious’. The food that we eat is categorized into three main groups: dietary nutrition (what we eat to sustain our body’s requirements); occupational nutrition (the food that we use to promote our body’s general health), and food ingredients (an agent that maintains and promotes the quality of a food). Our food consumption has become a complex mix of physiological, economic, and environmental factors that we are unable to change without assistance.
Plants manufacture carbohydrates and energy from light and the sun, and these fuels are stored in starch and sugars in the form of starch-based foods and in fat and protein in the form of protein-based foods. A variety of enzymes are used to break down the foods and create energy. Carbohydrates, including glucose and fructose, are stored in our cells as energy sources for cellular function; fats are used for energy, but are generally toxic and are removed by processes called ketosis, while proteins, including amino acids, are metabolized to release energy in the form of glucose for use by the body.
In addition to carbohydrates and fats, the human body also produces some important molecules and substances, including enzymes, hormones, receptors, lectins, hormones, and immune system determinants. The role of each of these determinants varies according to the type of cell that they belong to. Enzymes are mainly directed at producing enzymes, which are catalysts, that help in the breaking down of food into simpler compounds that can be used and disposed of by the body. In contrast, lectins act as inhibitors, making it impossible for certain molecules to bond with other molecules in food and causing them to become separated.