Dietary Macronutrients - Nutritional Components of Food
Health as defined by the world health organization (WHO) is
defined as the state of complete physical, mental, and social well being and not
merely the absence of disease and infirmity. The knowledge of food and nutrition
has a direct influence in maintaining good health of an individual.
is a complex mixture of various substances, which help:
- To provide
sufficient energy & heat for the various activities & body work.
In growth, repair & maintenance of body tissues.
- In adding bulk
to the diet to keep the digestive system, work well.
is the science of foods which deals with the dynamic process in which the food
consumed is digested, nutrients are absorbed, distributed to body tissues for
utilization & wastes are disposed off the body. Nutrients are the constituents
in food that must be supplied to the body in suitable amounts.
addition, to acquire a sound health one must include a daily routine of consuming
a balanced diet comprising of all the food groups and vital components in appropriate
The dietary components of food are:
Moreover, these are
broadly classified into three groups:
- Energy giving: it comprises
of carbohydrates & fats, which provides us with most of our energy required.
building foods: these are rich in proteins & are involved in growth &
repair of body cells.
- Protective foods: these are rich in vitamins
& minerals & are involved in building up the body's immune system.
let us briefly know that why all these components are so important & what
all functions they perform.
These form the main
bulk of diet & are the chief source of energy. They play an important role
in metabolism of fats & in forming protein structures (non-essential amino
It includes the sugars & starches.
- Candy, soft drinks,
sweets, desserts contain lots of sugar.
- Bread, breakfast cereals,
potatoes, & rice contain starch.
In a balanced diet, 60%
of our daily calorie requirement should come from carbohydrates. However the amount
can vary from 50%-70%.
These are more concentrated
source of energy than carbs. However, amount should be in limit as high intake
can lead to many harmful diseases in the long run.
If taken in appropriate
amount body fat serves as a source of quick energy in times of starvation or fasting.
Furthermore, it is required for the absorption of vitamins A, D, E & K.
gives flavor & taste to the food.
- It provides a cushioning support
to our internal vital organs.
- It provides essential fatty acids (EFA)
which helps in reducing blood cholesterol, promotes growth, & maintains skin
When products include hydrogenated oils/trans fats it
means that the amount of EFA in these products is greatly reduced and these should
not be consumed on a daily basis. Fats can be obtained from butter, whole milk,
oils, fish, nuts& seeds, ice-creams etc. nuts & seeds & fishes are
rich sources of EFA's. The fat in a balanced diet should provide 20-25% of total
energy (i.e. 10-20gms). However, young children can utilize & need extra amount
of good fats.
Like carbs & fats these also provide
energy but due to the presence of nitrogen in their structure they perform one
of the most vital functions needed for a healthy life i.e. for building up of
body's cells & tissues & for repairing & maintaining the worn out
tissues. It also helps in synthesis of antibodies, enzymes, & hormones.
sources of proteins are of better quality are readily absorbed & utilized
by the body. These include milk & milk products, eggs, meat, poultry, fish,
liver & an exception is soybean, which is a plant source. Plant sources include
cereals, pulses, dry fruits, nuts, beans etc.
Daily requirement of protein
is 1g/kg body weight. For e.g. A normal adult man of 60kg will require 60gm of
protein. However, in stage of growth or illness requirement is increased.
are required in very small amounts but are important for our growth & development.
They make enzymes, which help to progress our body's chemical reactions. They
should be regularly consumed as their deficiency can lead to diseases such as
night blindness, scurvy, pellagra, etc.
There are fat-soluble vitamins (A,
D, and E&K) and water-soluble vitamins (B-complex & C). Chief sources
include vegetables & fruits & our diet should include these in most of
These are also needed in small amounts but
are important for our body's basic growth & structure. There are some 50 minerals
in our body serving important functions like formation of bones & teeth, formation
of blood, hair growth, nail growth, skin integrity etc. Food sources include -
egg, meat, milk, cheese, nuts, vegetables, beans, banana, orange, melons, salt
It is a type of carbohydrate found in vegetables,
fruits, & whole grains, which absorbs water & increases bulk of intestinal
contents & helps in intestinal movements. Its deficiency leads to constipation.
It also lowers cholesterol & helps in weight reduction.
not a food, it is an important component of our diets. It is required for our
basic metabolism as serves as a medium for all chemical reactions, maintains our
body's temperature, helps in nutrition processes etc. A 10% loss of water can
lead to dehydration & a 20% loss may even lead to death. A daily diet is not
complete without consumption of 8-10 glasses of water.
Health is often taken for granted, & its value is not fully
understood until it is lost. So don't be losers & have a healthy
life with a balanced diet!