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Understanding Concepts- Food, Functions of Food,
Components of Food and their functions, Obesity, Balanced Diet, Deficiency
Diseases
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Introduction-Food
is the basic requirement of all living organisms. We eat different kinds of
food. Some foods provide us energy, some food provide us energy to work, some
food help in development and maintenance of body while some others keep us healthy and strong. Food provides
different kinds of nutrients. By eating different varieties of food, we get
different kinds of nutrients. The food on which daily energy and nutrients
requirements of a person / organism depends is called diet.
Functions of Food-Following
are the functions of food-
1.
Food
give us energy to do various activities
2.
Food
helps us for the growth and development of our body.
3.
Food
provides various nutrients for maintenance of body.
4.
Food
helps in repair of injury and cut, replacing dead tissue and healing of wounds.
5.
Food
helps to fight against germ (pathogens) and protect us from diseases.
6.
A
balanced and healthy food makes us healthy and strong.
Components
of Food-In different parts of the world different kinds of food are
eaten. The main food eaten in any region is called staple food. e.g.- Rice, wheat
flour (Atta), pearl millet (bajra), potato and pulses are the staple foods of
India. The climatic conditions and prevailing food habits decide the type of
crops cultivated in any region.
The dish (prepared food) contains one or
more ingredients. The essential things called nutrients are found in the food. The
nutrients are of two types-
(a) Micro-nutrients-
(b) Macro-nutrients-
Micro-nutrients are required in fewer
amounts while macro-nutrients are required in more amounts. These nutrients
belong to seven categories- carbohydrate, protein, fats (lipids), vitamins,
minerals, dietary fibers and water.
1. Carbohydrate- They give energy by undergoing
digestion and then by oxidation inside the cells. Glucose, a carbohydrate is
formed during photosynthesis in plants. Glucose changes to starch (a complex
carbohydrate) in plants. Carbohydrates
are sweet in taste. The carbohydrate is found in potato, rice, wheat, sugar, sweet
fruits etc. Carbohydrate turns bluish- black in colour on testing with iodine.
2. Protein- Proteins are body building
components of food. They help in formation of new cells. They help in repair of
injured cells, growth and development of body.
Proteins are of different types. On adding 10 drops of sodium hydroxide
and 2 drops of Copper (II) sulphate the sample of protein changes to bluish-
violet colour. This is called Biurette test of protein. Protein is found in – milk, eggs, fish, meat,
soya bean, grams, peas, lentils, beans, etc. Milk is called complete food. It
gives carbohydrate, protein, fat, calcium and phosphorus like minerals.
Functions-Protein
helps in growth and development of the body. Protein is helpful for nails,
hairs, skin and muscles. Proteins help in repair of injured cells. In Red blood
cells protein is found.
3. Fats (Lipids)-They are richest source of
energy as compared to carbohydrates. Excess fat is stored in our body and gives
energy as per requirement. Polar bears, walrus and whale especially store fats
in their body. Fats in liquid state are called lipids. Fats add flavor to food
along with spices. When the fatty or oily substance like poori, pakauri, chips
etc. is taken in the white paper, some
greasy spots can be seen.
Functions- Fats give
highest energy on oxidation in the cells. Fats keep the body warm by making a
thermal insulator layer below the skin. So, the loss of heat of the body is
negligible. The deposition of fat as a layer below the skin protect from jerks.
4. Vitamins-Vitamins are essential for the
protection of body from diseases. They are required in trace amount. Deficiency
diseases are caused due to lack of vitamins. e. g-Anemia, Rickets, Scurvy etc.
Vitamins are mainly found in fruits and vegetables. Vitamins are also found in
cereals, milk, honey, egg, fish, meat, pulses and sprouts. Vitamins are taken
from outside our body but in the sunlight our body can prepare vitamin D.
On the basis of
their solubility, there are two types of vitamins-
(i) Fat soluble vitamins- They
are easily absorbed by the body fats. E.g.- Vitamin- A, D, E, and K.
(ii) Water soluble vitamins- They
dissolve in water. Excess amount of these kinds of vitamins are removed from
the body through urine. e.g.- Vitamin B Complex and Vitamin C.
Functions-
(A). Vitamin A helps in keeping eyes and skin
healthy, normal growth, and prevent from infections.
(B). Vitamin B-Complex (B1,
B2, B3, B5, B6 and B12)
help in normal digestion of carbohydrate, protein and fats. They help in normal
growth and nervous tissue functions.
Vitamin B12 prevents from anemia.
(C). Vitamin C-It, chemical name is ascorbic acid. It is useful for
skin, teeth, gums, bones, immunity development and formation of red blood
cells. Indian gooseberry (Amla) (Phyllanthus
emblica or Emblica officinalis) is
the richest source of vitamin C. Citrus fruits like –lemon, orange, turmeric,
tomato, oranges, melons vegetables etc are good sources of vitamin C.
(D). Vitamin D- It’s chemical name is
calciferol. It helps in absorption of calcium to teeth and bones. Sunlight
helps in formation of Vitamin D in our body.
(E). Vitamin E- It’s deficiency causes infertility. It helps in protecting
eyesight, glowing skin, boosting immunity, reduces chance of heart problems and
cancer. It is found in vegetables, fruits, sprouts and edible oils.
(K). Vitamin K- It helps in blood clotting during injury. It is found in
cereals, groundnuts, potatoes, meat, fish and chicken.
5. Mineral-salts- Mineral salts are essentially
required in trace amount. About 20 types of mineral-salts are required by our
body. Mineral-salts help in proper growth, development and maintenance of the
body. E.g.-Calcium-it is essential for bones teeth and blood clotting. It is
found in milk, milk products, vegetables, fruits, meat etc.
e.g.-Iodine- is necessary for normal growth of mind and body. It is
necessary for thyroxin hormone formation by thyroid gland. Iodine is found in
iodized salt, ocean fish, water, eggs, pineapple, tomato, spinaches, papaya etc.
e.g.-Iron- It is an essential part of hemoglobin found in red blood cells that help in carrying oxygen in our body. Iron is found in apple, papaya,
sugarcane juice, jaggery, vegetables, spinach, meat, chicken, fish etc.
Other important minerals are phosphorus,
manganese, sodium, potassium etc.
6.
Dietary fibres (Roughages)-They are fibres present in the food. They do not provide any energy but help
in cleaning the alimentary canal of the body. Plant based foods like
vegetables, fruits, cereals, pulses, potatoes etc provide dietary fibres.
Dietary fibres helps in digestion by bowel movement, do not cause constipation,
control blood sugar level, reduce cholesterol level
and retain water in the
body.
7. Water- About 70 % of our body is made up of water. Water
is necessary for metabolic activities and
fulfills mineral-salts requirements. Water regulates the body temperature. The
excess salts, urine and waste materials are removed from the body due to water.
It dilutes the blood and help in transportation of nutrients.
Obesity- Overeating and not doing exercise, enough
work causes obesity. Persons suffering from obesity are called obese.
Obesity makes the person unhealthy and
unfit to do work efficiently. Food calories should be taken in required amount
and must be burnt to reduce over weight.
Balanced Diet-A diet that contains carbohydrate,
protein, fats, vitamins, minerals and dietary fibres (roughages) in required
proportion is called a balanced diet.
Balanced diet is necessary for growth, development and maintenance of
good health. The energy present in the food is measured in calories. Every kind
of food has some calories. We should take calories as per our age and nature of
work we do.
Deficiency Diseases- Those diseases which are caused due to lack of taking
of essential nutrients, vitamins, minerals in the food for long time are called
deficiency diseases. Deficiency diseases can be lethal. Taking of balanced diet
prevents deficiency diseases. e.g.- Kwashiorkor, Marasmus, Anemia, Rickets,
Scurvy, Night blindness, Goiter , Beriberi etc.
Vitamin/ Mineral
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Deficiency
disease/disorder
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Symptom
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Vitamin A
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Loss of vision
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Loss of vision,
Less vision, night blindness
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Vitamin B1
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Beriberi
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Less energy, Weak muscles
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Vitamin C
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Scurvy
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Less healing of wound, bleeding gum
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Vitamin D
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Rickets
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Soft bones and
bending
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Calcium
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Bone and Tooth
Decay
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Weak bones ,Tooth decay
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Iodine
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Goiter
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Mental weakness, Swollen
neck
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Iron
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Anemia
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Fatigue, Breathlessness
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PROJECT WORKS--
1. Prepare a group
project on healthy eating habits.
2. Prepare a diet chart
for- a baby, an adolescent boy, an adolescent girl, an adult person and an old
person.
3. Explain deficiency
diseases with a suitable table of characteristics of deficiency diseases.
4. Prepare a detailed
report on excess eating of fats, protein and vitamins.
5. What should be the
diet for a milch and a drought animal? Describe.
CHECK YOUR
PROGRESS Time =40 Minutes Total Marks= 5
x 4 = 20
1. What is food? Write
all its components.
2. Write one function
each of- Carbohydrate, proteins, fats, Vitamins, minerals and dietary fibres.
3. What is balanced
diet? Write its advantage.
4. What are deficiency
diseases? Cite three examples of such diseases.
SOLVED EXERCISE QUESTIONS
Q.1 Name the major nutrients in our food.
Ans- The major nutrients in our food are- carbohydrate, protein, fats (lipids),
vitamins and minerals. Dietary fibres and water are minor nutrients.
Q.2 Name the following:
(a) The nutrients which mainly give energy
to our body.
(b) The nutrients that are needed for the
growth and maintenance of our body.
(c) A vitamin required for maintaining good
eyesight.
(d) A mineral that is required for keeping
our bones healthy.
Ans- (a) Carbohydrate
and fats (lipids) (b) Protein
(c) Vitamin A (d)
calcium
Q.3 Name two foods rich
in:
(a) Fats
(b) starch (c) Dietary
fibres (d)
Protein
Ans- (a) Fats- Cooking
oil, Butter (b)
Starch- Rice, Potato
(c) Dietary fibres- Vegetables, Fruits (d)
Protein- Milk, Eggs
Q.4 Tick (√) the statements that are correct.
(a) By eating rice alone, we can fulfill
nutritional requirement of our body.
( )
(b) Deficiency diseases can be prevented by
eating a balanced diet. ( )
(c)
Balanced diet for the body should contain a variety of food items( )
(d) Meal alone is sufficient to provide all
nutrients to the body. ( )
Ans- (a) Incorrect
(x) (b) Correct (√)
(c) Correct (√) (d)Incorrect(x)
Q.5 Fill in the blanks.
(a) …………is caused by deficiency of Vitamin
D.
(b) Deficiency of …………causes a disease known as beri-beri.
(c)
Deficiency of Vitamin C causes a disease known as …………
(d) Night blindness is caused due to
deficiency of ……..in our food.
Ans- (a) Rickets (b) Vitamin B1
(c) Scurvy
(d)
Vitamin A
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