Nutrition

Nutrition is the term that is used to describe the provision of essential life supporting material to an organism through food.  The science of nutrition analyses the physiological and metabolic responses of a body to the diet that is provided to it. An increasing concern in metabolism and the different metabolic pathways are shown these days in nutritional studies because of advancements in biochemistry, genetics, and molecular biology.

Human body has many chemical substances like carbohydrates, water, fatty acids, amino acids, nucleic acids, etc. These substances are made up of elements like oxygen, hydrogen, carbon, nitrogen, calcium, iron, phosphorus, magnesium, zinc, manganese, etc. These chemical substances and elements are present in different combinations and structures like vitamins, hydroxyapatite, phospholipids, hormones, etc.

There are also such elements and substances that are in taken in the form of food, digested, absorbed and distributed to all the cells and tissues of the body via blood stream. Digestion breaks down the complex compounds into simpler ones so that they can be absorbed into the system. The waste material is eliminated in the form of excreta.

There are 6 main nutrient classes that are absorbed from food by the human system. These include the fats, carbohydrates, proteins, minerals, water and vitamins. Those nutrients that are needed in large quantities by the body are known as macronutrients and those in minor quantities as micronutrients. Proteins, fats, carbohydrates, and water are therefore macronutrients; and vitamins and minerals are micronutrients.

The macronutrients other than water are utilized for generating energy and structural materials in the body. But water and the micronutrients are used for other purposes. Another dietary material that does not belong to both of these categories is the fiber. It is essential both for biochemical and mechanical purposes in the body. Other than the minerals and vitamins, some other micronutrients also exist. These include the antioxidants and phytochemicals.