1. Carbohydrates: Sugar, honey, starch, potatoes,
rice, wheat, etc., are carbohydrates. They are
compounds of carbon, hydrogen, oxygen, sugar,
starch, etc. They provide about half of the
required energy and thus maintain the
temperature of the body. Energy is produced by
the burning of sugar.
2. Proteins: Eggs, beans, pulses, fish, etc., are
proteins. These are compounds having an excess
of nitrogen with carbon, hydrogen, oxygen and
sometimes sulphur and phosphorus. They are
mainly responsible for growth. Eggs, meat, pulses,
etc., are the richest source of proteins. Their
absence causes •extreme weakness.
3. Fats and Oils: Oils, nuts, ghee, butter, etc. They
contain same components as carbohydrates and
are better sources of energy which is again
produced by burning. Their deficiency in the body
causes several diseases while excess is stored
beneath the skin.
4. Vitamins: Every food almost contains some
vitamins. They are organic substances which are
essential for the growth of the body and are
required in small amounts. Their deficiency causes
sickness and stunted growth. Each of them
performs definite functions as
(a) Vitamin A is present in cod, halibut, shark
liver oils, eggs, green vegetables, etc. It is
essential for growth of the body and protects skin
and other delicate parts of the body. It prevents
infection and keeps the eyes healthy. Its
deficiency causes night blindness and stunted
growth of the body.
(b) Vitamin Bt complex is found in yeast, green
vegetables, cereals, etc. Its deficiency leads to
beriberi and anaemia.
(c) Vitamin B2 complex is the mixture of about
twelve components. It is present in milk, butter,
cereals, vegetables, etc. This is very important for
growth and blood. The deficiency of this complex
leads to subnormal growth, pellagra, etc.
(d) Vitamin C is present in large quantities in
vegetables, fresh fruits, orange, etc. Human milk
is also a good source of vitamin C. Its deficiency
causes scurvy, anaemia, impaired growth,
haemorrhage and susceptibility to infection.
(e) Vitamin D is present in cod, shark liver oil,
milk, butter, etc. Its deficiency causes rickets in
children and osteomalacia inWadult females.
(f) Vitamin E is found in cereals, green vegetables,
eggs, etc. Deficiency of this vitamin causes
(g) Vitamin K is mainly confined to green
vegetables. This vitamin maintains normal
clotting of blood.
(h) Vitamin P is present in association with
vitamin C and its functions are closely associated
with the same vitamin. It helps the action of
vitamin C and keeps the blood capillary healthy.
5. Inorganic Salts: Vegetables, fruits, etc. Salts of
calcium, potassium, magnesium, iron, sulphur,
iodine, etc., are essential for the health of the
6. Water: Most of the food contains water. Water
constitutes 75 per cent of our body. It helps the
digestion and absorption of food. It also
maintains the temperature of body and removes