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Monday, 9 May 2011

Food and Nutrition

Food is necessary for every human being to survive. Food is any thing consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, minerals and water.

Balanced diet or nutrition, includes all the elements necessary to produce energy, maintain life, health and stimulate growth. Balanced diet is the provision to humans to obtain the materials necessary to support life. Balanced diet requires the proper ingestion and, equally important, the absorption of proper nutrition. Dietary habits and choices play a significant role in health and mortality. Improper  diet, can not complete basic needs of body and person may fall in various diseases.

Function of Foods:

The body uses food to perform some main functions:


Food supplies energy needed to perform many tasks of everyday living. We need energy to think, breathe, walk, sit, speak and even sleep. We get energy from carbohydrates, proteins and fats. It is important that we eat enough food to supply all our needs. If we do not eat properly, we will feel tired and spiritless. If we eat more energy food than our body needs, this energy will be stored in the body as fat. Too much stored energy will result in the body becoming overweight or obese.

Growth and repair

Food provides the materials needed to build, repair and maintain body tissues. Proteins, fats and minerals are the best nutrients for growth. Growing bodies need extra amounts of these nutrients. Every person, whether growing or not, is going through a continual repair process of replacing injured or dead cells. It is food that supplies the nutrients necessary for this process.


Food supplies the substances that help regulate the body's processes. Water, vitamins and minerals help regulate breathing, the nervous system, digestion, blood circulation and the elimination of waste products from the body. They help keep all the systems in the body working properly.


Vitamins, minerals and protein keep the body's tissues, organs and bones healthy. Healthy organs are less likely to be attacked by diseases.


Carbohydrates perform numerous roles in living things and are a common source of energy in living organisms. Foods high in carbohydrate include fruits, sweets, soft drinks, breads, pastas, beans, potatoes, bran, rice, and cereals.

Functions of carbohydrates:

Carbohydrates spare protein so that protein can concentrate on building, repairing,
and maintaining body tissues instead of being used up as an energy source.

It is necessary for the regulation of nerve tissue and is the only
source of energy for the brain.

Certain types of carbohydrates encourage the growth of healthy bacteria in the
intestines for digestion.

Some carbohydrates are high in fibre, which helps prevent constipation and
lowers the risk for certain diseases such as cancer, heart disease and diabetes.


Fats play a vital role in maintaining healthy skin and hair, insulating body organs against shock, maintaining body temperature, and promoting healthy cell function. It also serve as energy stores for the body.They are broken down in the body to release glycerol and free fatty acids. The glycerol can be converted to glucose by the liver and thus used as a source of energy.It also serves as a useful buffer towards a host of diseases.This helps to protect vital organs, until such time as the offending substances can be metabolized and/or removed from the body by such means as excretion, urination, accidental or intentional bloodletting, sebum excretion, and hair growth.

Edible animal fats are fish oil, and butter or ghee. They are obtained from fats in the milk and meat, as well as from under the skin, of an animal. Edible plant fats include peanut, soya bean, sunflower, sesame, coconut, olive, and vegetable oils. Margarine and vegetable shortening, which can be derived from the above oils, are used mainly for baking. These examples of fats can be categorized into saturated fats and unsaturated fats.

Functions of Fats:

Fat is essential for the proper functioning of the body.

It provide essential fatty acids, which are not made by the body and must be obtained from food. The essential fatty acids are linoleic and linolenic acid. They are important for controlling inflammation, blood clotting, and brain development.

Fat serves as the storage substance for the body's extra calories. It fills the fat cells that help insulate the body.Fats are also an important energy source. When the body has used up the calories from carbohydrates, which occurs after the first 20 minutes of exercise, it begins to depend on the calories from fat.

Healthy skin and hair are maintained by fat. Fat helps the body absorb and move the vitamins A, D, E, and K through the bloodstream.


Proteins serve various functions in the body,  Some proteins are involved in structural support, while others are involved in bodily movement, or in defense against germs. They vary in structure as well as function. They are constructed from a set of 20 amino acids and have distinct three-dimensional shapes. Below is a list of several types of proteins and their functions.


There are specialized proteins involved in defending the body from antigens. One way antibodies destroy antigens is by immobilizing them so that they can be destroyed by white blood cells. Proteins are responsible for movement. Examples include actin and myosin. These proteins are involved in muscle contraction and movement.

Sources of proteins:

There are two sources of proteins, vegetables and animals.

Vegetable source

It includes cereals, wheat, lentils, beans, peas and chick pea etc.

Animal source

It includes meat, eggs, fish,milk, yogurt, and cheese etc.


Vitamins are classified as either water-soluble or fat-soluble. In humans there are 13 vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C). Water-soluble vitamins dissolve easily in water and, in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin consumption. Because they are not readily stored, consistent daily intake is important. Many types of water-soluble vitamins are synthesized by bacteria. Fat-soluble vitamins are absorbed through the intestinal tract with the help of lipids (fats). Because they are more likely to accumulate in the body, they are more likely to lead to hypervitaminosis than are water-soluble vitamins.

Fat soluble vitamins:

Vitamin A

Promotes skeletal growth, normal tooth structure, healthy mucous membranes, healthy skin, eyes and hair; essential for night vision. It is in fish liver oils, liver, carrots, green and yellow vegetables, dairy products.

Vitamin D

Promotes bone and tooth development and normal growth; aids utilization of phosphorus and calcium; maintains nervous system and heart action; prevents rickets.

Vitamin E

Protects body's store of Vitamin A, tissues and fat from destructive oxidation, and breakdown of red corpuscles; strengthens capillary walls; regulates menstrual rhythm; prevents loss of other vitamins; aids blood flow to heart; lowers blood cholesterol and fatty acids; vital to cell health; regulates protein and calcium metabolism. It is in soyabeans, vegetable oils, broccoli, brussels sprouts, leafy greens, enriched flour, whole wheat, wheat germ, whole grain cereals, eggs.

Vitamin K

The role vitamin K plays in bone metabolism triggered a new thinking in its use as a therapeutic agent in diseases related with bone like osteoporosis. It is best known for its role in helping blood clot (coagulate) properly. Vitamin K also plays an important role in bone health.

Water soluble vitamins:

Vitamin C

Essential for the formation of collagen, needed for absorption of iron, some proteins and folic acid. It prevents oxidation of other vitamins, aids in metabolism of amino acids and calcium, stops internal bleeding and strengthens blood vessels. It maintains hard bones and teeth, promotes stamina, holds body cells together prevents infections, colds, fatigue and stress. It reduces allergies, heals wounds and burns. Main source of vitamin c are citrus fruits, berries, green and leafy vegetables, tomatoes, cauliflower, potatoes, sweet potatoes.

Vitamin B Complex

Other common names are B vitamins; vitamins B1, B2, B3, B5, B6, B7, B9, and B12. they are also known by scientific/medical names thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid or folate (B9), cobalamin (B12)


B vitamins are essential for growth, development, and a variety of other bodily functions. They play a major role in the activities of enzymes, proteins that regulate chemical reactions in the body, which are important in turning food into energy and other needed substances. B vitamins are found in plant and animal food sources.

Vitamin B1 (thiamin) and vitamin B2 (riboflavin) help the body produce energy and affect enzymes that influence the muscles, nerves, and heart.

Vitamin B3 (niacin) has a role in energy production in cells and helps keep the skin, nervous system, and digestive system healthy.

Vitamin B5 (pantothenic acid) influences normal growth and development.

Vitamin B6 (pyridoxine) helps the body break down protein and helps maintain the health of red blood cells, the nervous system, and parts of the immune system.

Vitamin B7 (biotin) helps break down protein and carbohydrates and helps the body make hormones.

Vitamin B9 (folic acid) helps the cells in the body make and maintain DNA and is important in the production of red blood cells.

Vitamin B12 (cobalamin) plays a role in the body's growth and development. It also has a part in producing blood cells, nervous system function, and how the body uses folic acid and carbohydrates.


Just like vitamins, minerals help your body grow, develop, and stay healthy. The body uses minerals to perform many different functions from building strong bones to transmitting nerve impulses. Some minerals are even used to make hormones or maintain a normal heartbeat. Minerals are important for your body to stay healthy. Your body uses minerals for many different jobs, including building bones, making hormones and regulating your heartbeat.


In human body calcium exists in more quantity than other minerals. A large amount of calcium is in milk and things made by milk. It is necessary for bones and teeth. Builds bones and teeth, muscle contraction, heart action, nerve impulses, blood clotting.


Phosphrus also play a vital role for the growth of teeth and bones, it helps in absorption of different food nutrients. Builds bones and teeth, energy production, acid-base balance, necessary in metabolism and cell membranes, calcium absorption


It is an important element for our body, it helps in providing oxygen to our body. It is about 55 to 60 percent in our blood. Iron is an essential mineral that is required for human life. Much of the iron in the body is found in red blood cells and carries oxygen to every cell in the body.


Aids thyroid gland, prevents goiter and helps burn fat. It converts carotene into Vitamin A, aids absorption of carbohydrates from small intestine, promotes growth and regulates energy production. it maintains hair, nails skin and teeth. It is in kelp, seafood, vegetables.


It is an important element for human survival. Our body contains large amount of water, it helps in absorption of food in body. It plays a critical role in regulating body temperature. It carries nutrients throughout the body. It improves digestion, eliminates waste and toxins from the body.