The Nutrition Of Food
There are two broad categories of food: human food and animal food. Human food refers to any material made up of matter that is consumed by humans. Animal food, on the other hand, refers to any material that is consumed by animals for their primary source of food. Both types of food may be broadly classified into three major groups: plant food, which includes animal products; animal-based foods, which include poultry, fish and eggs; and fruits, vegetables and nuts. Animal food can also include meat and milk products.
The first group of food is called primary food, i.e., the basic food types that form the basis of many foods that we eat on a daily basis. This food type is generally rich in protein, vitamins and minerals and is generally eaten on a regular basis. This group of food is called complete because it provides a complete quantity of nutrition required by the body. In contrast, processed food usually contains little or no nutrient content in the form of nutrients essential to our body function.
Processed food is high in fat, sugar, salt and other preservatives, artificial flavorings and colorings, coloring and packaging materials, added flavor, or artificial sweeteners. Often, food colorings (such as blueberries, redcurrants, or lemon drops) added to foods to make them more appealing to customers lead to health problems over time, including cancer. Preservatives are often added to processed foods to extend shelf life. However, chemicals such as ethylene glycol, saccharin and sodium benzoate have been associated with health problems, especially in growing children.
A large number of food additives used today originated in Europe during the industrial revolution. These food additives were originally used to increase the shelf life of processed foods and also to add a pleasant flavor. They include such common additives as salt, sugar, artificial flavoring, aspartame, and saccharin. Today, some of these chemical additives are banned in the US due to their known health risks. Still, many food manufacturers use them despite the risk.
Our food system is designed to distribute nutrients from the major food groups primarily in proportions based on their caloric value. Thus, carbohydrates are generally considered to be the most important source of nutrients. However, carbohydrates can be broken down into several forms such as simple sugars or starches. Dehydrogenated oils that are mainly used for frying are made up of complex carbohydrates that are not classified as nutrients because they are not classified as vitamins. Fats are classified as the richest source of nutrients.
The major categories of nutrients are carbohydrates, proteins, vegetables, fruits, and fats. These nutrients can be separated further into vitamins and minerals. Vitamins are water-soluble and need to be absorbed through the digestive system while minerals can be insoluble and are not immediately absorbable by the body. Foods that are rich in vitamins are usually rich in other nutrients as well such as antioxidants. Antioxidants prevent free radical damage and enhance cell vitality. Free radicals are a leading cause of diseases and aging.