The word food refers to anything consumed to supply body requirements and is therefore present in different forms at different times throughout the day. Food is generally of animal, plant or floral source, and has important nutrients, including proteins, fats, vitamins, or other minerals, which are required by the human body. These nourishments are then used to help build and repair body tissues.
All foods have some nutrients which are fat-soluble, i.e. they are stored only in fat tissues, and in some cases they can be lost from the body during normal daily activity. The rest, known as the non-fat soluble vitamins, are easily absorbed by the body and can therefore contribute to a healthy weight. Therefore the classification of food is often based on the content of fat-soluble and non-fat soluble vitamins in each food group.
There are two broad categories of food ingredients and these are organic and synthetic, with each having its own set of nutrients which are not to be confused with the others. A synthetic food ingredient may include any number of substances, including artificial colours, flavourings, preservatives, salt, sugar, vitamins and more. An organic food ingredient includes only those elements which are natural. For example, milk is an organic food ingredient because it is produced from milk cows, although the milk itself may be from another source.
There are different kinds of food that provide the body with the various essential nutrients and building blocks that are needed for health and the maintenance of good health, and these are known as macronutrients. Macronutrients consist of carbohydrates, protein, vegetables and fibre. It is the combination of the three that provide the dietary energy that the body needs to carry out the day, and so it is important to choose the right combination of macronutrients to get the best from your diet.
There are two classifications of macronutrients – simple and complex. Simple carbohydrates are the main source of food energy, which you need in order to perform a wide range of daily functions in the body; for example, the majority of the food you eat (whether it be carbohydrates or fats) consists of simple carbohydrates. As well as being energy, they are also easily converted to glycogen, which is stored as glycogen in the muscles and liver, and so helps to reduce the amount of fat that you consume. They are generally stored as fatty acids in the liver and therefore can contribute to obesity if you eat too much of them. Complex carbohydrates on the other hand are found in fruit and vegetables (the richer the better), cereals, bread, beans, pulses, potatoes, rice and nuts.
However, the quality of the carbohydrates you eat is just as important as the types, so it is best to identify which carbohydrates are your best dietary fiber. A high-fibre carbohydrate food is one which contains a large amount of fibres, for example, oats, pulses and nuts. However, you should not rely solely on complex carbohydrates for energy, because they also contain some complex sugars. A good example of a fibrous food is that of barley, which contains large amounts of both proteins and complex carbohydrates. The reason behind this is that barley has a surprisingly high amount of bioactive phenolics (which are compounds that promote health), and these provide the link between the fibres and energy production in the body.