Nutrients And Their Functions - basics - dietucate

NUTRIENTS AND THEIR FUNCTIONS 

Every individual in this world wants to lead a healthy life. Food is the main basis for maintaining health. Everybody needs a wide range of nutrients to perform various functions in the body and to lead a healthy life. 

Nutrients are the constituents in food that must be supplied to the body in suitable amounts. 

Chemical substances obtained from food are used in the body to provide energy,  as structural materials and regulating agents to support growth,  maintenance and repair of the body's tissues. 

Nutrients can be divided into Macronutrients and Micronutrients.

Macronutrients 

Macronutrients are nutrients which we need in large quantities. They supply us with energy and are needed for growth and maintenance of the body's tissues. In addition to provide the body with energy , the macros serve a lot of other vital functions. Macro nutrients constitute the majority of individuals diet.

These include carbohydrates, proteins and fats.

Carbohydrates 

Carbohydrates are the main sources of energy for doing our daily work. They are the class of energy yielding substances which include starch, glucose, cane sugar, milk, sugar etc.

Food ingredients like simple sugars namely,  cane sugar and glucose,  honey are pure carbohydrates. Simple carbohydrates are generally the single glucose units. They are the easily available sugars in the form of sugary drinks. They are included in less amount in our diet. 

 Complex carbohydrates are found in food such as whole grains, vegetables, beans, roots and tubers etc. They have longer glucose chains, take longer to break down and provide long lasting energy in the body.

Functions of carbohydrates:-

1.  They supply energy for body functions and          for doing work. 

2.  They are essential for the oxidation of fats.

3.  They exert a sparing action on proteins. 

4.  They provide the carbon skeleton for the synthesis of some non-essential amino acids. 

5.   Starch which forms the main source of carbohydrates in the average diets has a bland taste and is non-irritant and hence it can be consumed in large amounts to provide major part of the energy requirements of the body.

Proteins

Proteins are vital to any living organisms. They are the important constituents of tissues and cells of the body. They form the important component of muscle and other tissues and vital body fluids like blood. 

Proteins are required for growth in children and maintenance of body weight in adults. They also provide energy to small extent. They constitutes of about 20 % of the body weight. 

Functions of proteins :-

1.  Protein helps in the growth and maintenance of the body. As they are the chief constituents of muscles,  organs and endocrine glands, also are the major constituents of skin , hair,  nails , bones ,teeth , blood , serum etc. 

2.  They also helps us to build up the immune as the antibodies necessary for these reactions are protein in nature.

3.  Enzymes  that are required in every step of digestion,  absorption and metabolism are also protein in nature.

4.  They provide amino acid for growth of foetus in pregnancy and for the production of milk proteins during lactation. 

5.  They also supply us with energy, they are the last source that the body taps for energy. 

Fats

Fat is an important component of the diet ans is more concentrated form of storage of energy than carbohydrates. It supplies per unit weight more than twice the energy furnished by either protein and carbohydrates. An ingested fat undergoes emulsification , digestion and absorption. It also imparts palatability to a diet and retards stomach emptying time. 

Fats in the diet can be of two types , the visible and invisible fat.

The visible fats are those derived from animals fats like butter, ghee which are solid fats and those derived from vegetable fats like mustard,  groundnut, coconut , Til etc. are liquid fats.

The invisible fats are those found in dairy  products,  biscuits,  cakes , fried foods,  cheese etc. are more difficult to spot. 

Functions of fats :- 

1.  It is a concentrated source of energy, yielding more than twice the energy supplied by carbohydrates per unit weight. 

2.  Fats are essential for the absorption of vitamins A, D , E , K and especially carotenoids present in foods of vegetable origin. 

3.  Fats helps to reduce the bulk of the diet as starchy foods absorb lot water during water.

4.  They are essential for the utilisation of galactose present in lactose. 

5.   Fat slows down the secretion of hydrochloric acid , muscles contractions and the rate of digestion. 

Micronutrients 

Micronutrients are essential elements which we require in small quantities in our daily life. They are critical to energy metabolism , cellular growth and differentiation , organ function and immune function. 

They include vitamins and minerals.

Vitamins 

Vitamins are organic substances present in small quantities in our foods. They perform vital functions in our body and many of them involves in the utilisation of carbohydrates,  fats and proteins. They are essential for health and wellbeing of the body.

They are classified as fat soluble vitamins and water soluble vitamins. 

Fat soluble vitamins- vitamins - A , D , E and K belong to this group. They are stored in the body and are not easily destroyed by ordinary cooking methods. 

Water soluble vitamins- B-complex vitamins and ascorbic acid belong to this group. They are unstable and not accumulated in the body but are also readily excreted. 

Functions of Vitamins :-

1.  Vitamin A is essential for vision in dim light and are also essential for normal bones formation,  skin and hairs.

2.  B complex vitamins keeps our nervous system healthy,  helps to produce red blood cells. 

3.  Vitamin C boosts our immune system,  helps to fight diseases , also necessary for growth and repair of our body.

4.  Vitamin D promotes the absorption of calcium and helps to keep our bones and teeth strong .

5.  Vitamin E protects the red blood cells from haemolysis by oxidizing agents and also good for healthy reproductive system.

6.  Vitamin K is necessary for blood coagulation. 

Minerals 

A number of minerals are present in the body. Some of these form part of body structural components and some others act as catalytic agents. The body contains about 24 minerals, all of which must be provided by the diet. These include calcium,  phosphorus, potassium, sodium, chlorine, magnesium, iron, manganese, copper,  iodine, cobalt, zinc,aluminium,  arsenic,  bromine, fluorine, nickel, chromium, cadmium,  selenium,  silicon,  vanadium, and molybdenum. 

Bones and skeleton are made up of mainly calcium,  magnesium and phosphorus,  iron is a component of blood. Minerals like zinc, molybdenum,  copper, manganese and magnesium are structural part or activate large number of enzyme systems. 

Functions of Minerals:-

1.  They are essential constituents of bones and teeth e.g. calcium,  phosphorus and magnesium. 

2.  As constituents of body cells of soft tissues such as muscles,  liver etc e.g. phosphorus 

3. As soluble salts which give to the body fluids and cell contents, there composition and stability which are both essential for life.

4. Iodine helps in the production of thyroid hormone and is also important for growth and development. 

5. Zinc is the constituent of an enzyme like carbonic anhydrase and hormone like insulin.