The word food can have different meanings to different people. To some people the word food can mean any of the following; food eaten in the diet, food eaten in its natural state (as in vegetables and fruits), food supplements, and the like. To others food means all of these things, but more specifically, food that is used to give life to an animal (in the case of plants). It also can mean food that is produced commercially, such as food for human consumption. Finally, it can refer to anything that an organism needs in order to grow and function normally.
The term food can be divided further into two broad categories, there are the macro-nutrients and the micro-nutrients. Macromolecules are the building blocks of proteins and can include amino acids, cysteines, proteins, enzymes, lectins, glycans and others. These are very important because without them, foods would not be able to be categorized as foods, nor would they be produced or consumed. On the other hand, the molecules referred to as nutrients are found in most plants, including fruits and vegetables, nuts and seeds, meats, dairy products, and the like. They are used to promote a healthy metabolism, enhance the immune system, and the production of hormones. Examples of micro nutrients include vitamins B and C, zinc, selenium, copper, iron, and manganese.
Most people today get their calories from either fat or carbohydrates. However, it should be noted that these two dietary elements are not actually the only ones responsible for the amount of calories we consume. Some of our calories (the ones we get from fat) are used to give energy to our muscles to do work, and carbohydrates are used to give us the energy we need to perform other activities. In addition to the above mentioned macro-nutrients, the micro-nutrients also play an important role in the process of obtaining adequate amounts of these macro-nutrients. These micro-nutrients come in the form of vitamins, minerals, and other nutrients needed in our daily food consumption. They can either be included in our diet already or can be added through nutrition supplements.