-
UNIT 1 FOOD, NUTRITION AND
HEALTH
Structure
I. 1 Introduction
1.2 Food and its Functions
1.3 Meaning of Nutrition
1.3.1 Nutrients : Action, Interaction and Balance
1.3.2 Handling of Food and Nutrients by the Body
1.3.3 Social. Psychologral and Econom~cAspects of Nutrition
1.4 The Concept of Health
1.4.1 Physical Health
1.4.2 Mental Health
1.4.3 Social Health
1.4.4 Spiritual Health
1.5 Meaning of Nutritional Status
1.6 Interrelationship between Nutrition and Health
1.7 Let I J s S u m U p
1.8 Glossary
1.9 Answers to Check Your Progress Exercises
1.1 INTRODUCTION
The word food brings to our mind countless images. Food is associated with worship
and divinity; with celebration and mourning; with family gatherings and with
community feasting. It is closely interwoven with every feature of our existence. This
is not surprising because food plays a crucial role in our lives. It sustains us. it
nourishes us. It is the 'life-giver".
This unit tells you about food and some of its components. It will give you some
idea about why food is essential for our survival. You will also be introduced to the
terms nurrltion and health.
Nutrition is the term used for the scientific study of food and how it is utilized by
the body. Eating the proper kinds of food in the right amounts is essential to keep us
healthy. In other words, our health is dependent on our eating pattern. This leads US
to the vital question-how much and what should one eat to keep healthy? How
much and what, for example, should an infant consume? Similarly, how much and
what foods should be consumed by a child, a n adolescent, an adult or an old person?
Further, what happens when one eats too much or too little? These are the types of
questions that a study of nutrition helps us answer.
:C Objectives
After studying this unit, you will be able to:
define food, nutrient, nutrition and health
list the functions of food
describe in simple terms how food is handled by.the body
discuss the social, psychological and economic aspects of food and eating
explain the concept of health and
1 discuss the relationship between food, health and disease.
!I 1.2 FOOD A N D ITS FUNCTIONS
What is food? The term food refers to anything which nourishes the body. It would
obviously include solids, semi-solids and liquids which can be consumed and which
help to sustain the body and keep it healthy.
, fi
'We ail know that food is a basic necessity Have you ever wondered why? Food is
essential becau~eit contains substanees which perform important funetions in our
body. These essential substances contributed by our food arc called nutrients. If
these nutrients are not present in our food in sufficient amounts, the result is ill
health and in some cases, even death. Food also contains many substances which are
non-nutrients e.g. colouring and flavouring substances in food.
Food is. therefore, a cohrplex.mirture of different nulrients and non-nuirients.
FUNCTIONS OF FOOD: You a n now.familiar with the fact that food consists in
part of various-nutrients. You may be surprised to know that there are over forty
essential nutrients, which are supplied by the food we eat. These nutrients can k
classified into five major categories (based on certain similar features): proteins,
carbghydrates, fats, vitamins and minerals. Water is important as a nutrieqt as well
as a food. You will learn more about this aspect in Unit 2, Block I.
Each of the nutrient categories has a specific physiological role to play. Here the
term "physiological role" refers t o the role of food in maintaining certain specific
body functions. Since food contains nutrients, it has physiological functions too, as
you will learn in the subsequent paragraph. Food also has social and psychological
functions in addition to physiological ones (Figure I .I).
Fig. 1.1 Fundlorn of food
Phystologlc-! :-unzt,ons: The physiological functions performed by food are the
energy-girrny. body-beriirfing, prorectdw and regularory funcrions. We need energy
every moment cf ocr lives for performing various types of activities such as sitting,
standing, walking and running and perforining all our household and other tasks.
You may not be aware of it but several activities take place within the body as well
e.g. beating of the heart, co~tractionof ihe intestines, expansion and contraction of
the lungs. Activities performed within the body also require expenditure of energy
The energy-giv~ngfunction of food is basically performed by two nutrient
categories--carbohydrates and fats. This is why these nutrients are also referred to as
the "body fue!s". The situation is sitnilar to the burning of coal or wood which are
familiar fuels. When these fuels are burnt, energy is released in the form of heat and
light. The fire we observe is, in fact, nothing bun the conversion of the energy locked
,!!p ~ r p:he. fuel to heat energy and iight enrrgv. Similarly, carbohydrates and fats are
burnt i n the b d y , The erlergy that ti:e>e ~uhstilnccccontain is,rcleascd to perform
the. various iictivi~iesthat $ve raikaci nbalrr earlier.
, Food is also needed for growth and repair. What is meant by these two terms:' As Food, Nutrition
you know, our body is made up of millions of units called cells. When growth takes and Health
place, new cells are added to the existing ones. The existing ones also increase in
size. On the other hand, cells d o get worn out and die. These cells have to be
replaced. This process is called repair. For both growth and repair, proteins are
ndeS'iary. We can understand the role of proteins in growth and development if we
just think of the tremendous increase in height and weight that occurs frcm infancy
to adulthood. How does this take place? This is made possible by the-process of
growth.
1. The other major physiolcgical functions performed by food are the protective and
legulatory functions. Let us talk about the meaning of the term 'protective' first.
I Here protective refers t o the role in preventing infection by ensuring proper
r
r
functioning of the body systems responsible for fighting infections. Even if a person
does develop an infection or any other type of illness, food and the nutrients it
contains facilitate rapid recovery. A person eating a poor diet would take much
longer to recover. He would get ill more easily as well.
The regulatory function mentioned earlier refers to the role of food in controlling
body processes. As you are aware, several processes take place in the body such as
the beating of the heart, maintenance of body temperature and contraction of
muscles. Each of these processes is controlled. Our body temperature, for example, is
maintained a t 98.4"F or 37'C. Similarly, the rate at which the heart beats is also
maintained. This is achieved by certain specific nutrients (among other substances)
and is illustrative of their regulatory function. Vitamins, minerals, and proteins
contribute substantially to both protective and regulatory functions. S o does water.
You are also probably aware that several chemical reactions take place in the body.
With the aid of these chemical reactions, simpler substances are used to build more
complex ones. Similarly, complex substances are broken down into their simpler
components. Figure 1.2 shows you how one or two types of simple units join to form
complex substances and how complex substances break down into their simpler
units. You will understand this better when you go through Units 2 and 3 of Block I.
The rate at which these reactions proceed is carefully controlled according to the
need of the body. Vitamins, minerals and proteins play a major role in contrnlling
these reactions i.e. they act as regulators.
Fig. 1.2 lnieconvenlon of almplr rnd romplex subutanca
, Basic Conclpts in Social Functionr: Food an.d eating has significant social meaning. Sharing food with
Nutrition-I any other person implies social acceptance. When you share a meal with anyone else,
you are expressing your acceptance of and friendship and respect for that person.
Earlier only perzons enjoying equal status in society ate together. A person would
never share a meal with someone inferior to him in social t e r n . Of course, we
observe considerable change in this respect now particularly in cities and t o m . In a
resdurant, for example, any person can eat irrespective of his social background if
he has the money to pay for the food.
i
Food is an integral part of festivity anywhere in the world. You must have surely
noticed that joyous occasio& such as the birth of a child or a marriage are
celebrated by having feasts and serving delicacies. Festivals such as Diwali,
Dussehra, Pongal, Onam. Lohri, Holi, Christmas and Id are celebrated by having
special and prescribed menus. In all these cases, food sewes the function of bringing
people together.
Food also has a specific significance and meaning in the religious context. Certain
food items such.as fruits, sweets and coconuts are offered to the deity in temples.
Often sweets are prepared at temples and gwdwarae and distributed to devotees as a
benediction or prasad. Further, people of a given religious community share a
common eating pattern. This is because religious texts and practices strongly
recommend some foods while rejecting others. Food thus becomes an integral part of
the social and religious life of people.
P~ycbolodalFundom: We all haw emotional needs s k h AS the need for mcitrity,
love and attention. Food is one way through which those needs are satisfied. When a
mother prepares her child's favourite dish, the child recognizes the fact that she lovm
him enough to remember his likes and dislikes. He appreciates the attention he is
given. As you arc aware, when people share food it serves as a token of friendship
and acceptance. A child quickly accepts foods eaten by his friends and by people he
admires or wants to identify with. He may even accept food he first found distasteful
if he observes his friends enjoying it. Sharing the same food as others around him
and those he considers important in his social sphere gives him a degree of
confidence in himself and reassures him that he will be accepted by others like him.
Food is also closely allied to our emotions. Food often serves as a reward. When a
mother wishes to reward her child for doing well in a test, she may buy him a sweet
or an ice cream. In this manner, that particular food item evokes pleasant feelings in
the mind of the child. On the other hand, certain foods become associated with
sickness such as khichri (a ricedal porridge). This type of food is generally eaten
when a person suffers from fever and may, therefore, not be associated with pleasant
feelings.
Check Your.Pro#re~Exercise 1
1) List the t h m functions of food.
2) Fill in the blanks.
a) The body-building function of food is ~ l a t e dto the presence of ................
b) Energy-giving foods are rickin carbohydrate and/or ..................................
C) ...................
Vitamins and minerals have............................and functions.
3) Read the following statements carefully. Comment in two sentences on whether '
the statement rekites to the physiological or social or psychological functions of
food.
a) Pankaj is celebrating his birthday. He has called his friends to his house for
a party in the evening. His mother has prepared several delicious dishes
particularly those which Pankaj likes.
UNIT 1 FOOD, NUTRITION AND
HEALTH
Structure
I. 1 Introduction
1.2 Food and its Functions
1.3 Meaning of Nutrition
1.3.1 Nutrients : Action, Interaction and Balance
1.3.2 Handling of Food and Nutrients by the Body
1.3.3 Social. Psychologral and Econom~cAspects of Nutrition
1.4 The Concept of Health
1.4.1 Physical Health
1.4.2 Mental Health
1.4.3 Social Health
1.4.4 Spiritual Health
1.5 Meaning of Nutritional Status
1.6 Interrelationship between Nutrition and Health
1.7 Let I J s S u m U p
1.8 Glossary
1.9 Answers to Check Your Progress Exercises
1.1 INTRODUCTION
The word food brings to our mind countless images. Food is associated with worship
and divinity; with celebration and mourning; with family gatherings and with
community feasting. It is closely interwoven with every feature of our existence. This
is not surprising because food plays a crucial role in our lives. It sustains us. it
nourishes us. It is the 'life-giver".
This unit tells you about food and some of its components. It will give you some
idea about why food is essential for our survival. You will also be introduced to the
terms nurrltion and health.
Nutrition is the term used for the scientific study of food and how it is utilized by
the body. Eating the proper kinds of food in the right amounts is essential to keep us
healthy. In other words, our health is dependent on our eating pattern. This leads US
to the vital question-how much and what should one eat to keep healthy? How
much and what, for example, should an infant consume? Similarly, how much and
what foods should be consumed by a child, a n adolescent, an adult or an old person?
Further, what happens when one eats too much or too little? These are the types of
questions that a study of nutrition helps us answer.
:C Objectives
After studying this unit, you will be able to:
define food, nutrient, nutrition and health
list the functions of food
describe in simple terms how food is handled by.the body
discuss the social, psychological and economic aspects of food and eating
explain the concept of health and
1 discuss the relationship between food, health and disease.
!I 1.2 FOOD A N D ITS FUNCTIONS
What is food? The term food refers to anything which nourishes the body. It would
obviously include solids, semi-solids and liquids which can be consumed and which
help to sustain the body and keep it healthy.
, fi
'We ail know that food is a basic necessity Have you ever wondered why? Food is
essential becau~eit contains substanees which perform important funetions in our
body. These essential substances contributed by our food arc called nutrients. If
these nutrients are not present in our food in sufficient amounts, the result is ill
health and in some cases, even death. Food also contains many substances which are
non-nutrients e.g. colouring and flavouring substances in food.
Food is. therefore, a cohrplex.mirture of different nulrients and non-nuirients.
FUNCTIONS OF FOOD: You a n now.familiar with the fact that food consists in
part of various-nutrients. You may be surprised to know that there are over forty
essential nutrients, which are supplied by the food we eat. These nutrients can k
classified into five major categories (based on certain similar features): proteins,
carbghydrates, fats, vitamins and minerals. Water is important as a nutrieqt as well
as a food. You will learn more about this aspect in Unit 2, Block I.
Each of the nutrient categories has a specific physiological role to play. Here the
term "physiological role" refers t o the role of food in maintaining certain specific
body functions. Since food contains nutrients, it has physiological functions too, as
you will learn in the subsequent paragraph. Food also has social and psychological
functions in addition to physiological ones (Figure I .I).
Fig. 1.1 Fundlorn of food
Phystologlc-! :-unzt,ons: The physiological functions performed by food are the
energy-girrny. body-beriirfing, prorectdw and regularory funcrions. We need energy
every moment cf ocr lives for performing various types of activities such as sitting,
standing, walking and running and perforining all our household and other tasks.
You may not be aware of it but several activities take place within the body as well
e.g. beating of the heart, co~tractionof ihe intestines, expansion and contraction of
the lungs. Activities performed within the body also require expenditure of energy
The energy-giv~ngfunction of food is basically performed by two nutrient
categories--carbohydrates and fats. This is why these nutrients are also referred to as
the "body fue!s". The situation is sitnilar to the burning of coal or wood which are
familiar fuels. When these fuels are burnt, energy is released in the form of heat and
light. The fire we observe is, in fact, nothing bun the conversion of the energy locked
,!!p ~ r p:he. fuel to heat energy and iight enrrgv. Similarly, carbohydrates and fats are
burnt i n the b d y , The erlergy that ti:e>e ~uhstilnccccontain is,rcleascd to perform
the. various iictivi~iesthat $ve raikaci nbalrr earlier.
, Food is also needed for growth and repair. What is meant by these two terms:' As Food, Nutrition
you know, our body is made up of millions of units called cells. When growth takes and Health
place, new cells are added to the existing ones. The existing ones also increase in
size. On the other hand, cells d o get worn out and die. These cells have to be
replaced. This process is called repair. For both growth and repair, proteins are
ndeS'iary. We can understand the role of proteins in growth and development if we
just think of the tremendous increase in height and weight that occurs frcm infancy
to adulthood. How does this take place? This is made possible by the-process of
growth.
1. The other major physiolcgical functions performed by food are the protective and
legulatory functions. Let us talk about the meaning of the term 'protective' first.
I Here protective refers t o the role in preventing infection by ensuring proper
r
r
functioning of the body systems responsible for fighting infections. Even if a person
does develop an infection or any other type of illness, food and the nutrients it
contains facilitate rapid recovery. A person eating a poor diet would take much
longer to recover. He would get ill more easily as well.
The regulatory function mentioned earlier refers to the role of food in controlling
body processes. As you are aware, several processes take place in the body such as
the beating of the heart, maintenance of body temperature and contraction of
muscles. Each of these processes is controlled. Our body temperature, for example, is
maintained a t 98.4"F or 37'C. Similarly, the rate at which the heart beats is also
maintained. This is achieved by certain specific nutrients (among other substances)
and is illustrative of their regulatory function. Vitamins, minerals, and proteins
contribute substantially to both protective and regulatory functions. S o does water.
You are also probably aware that several chemical reactions take place in the body.
With the aid of these chemical reactions, simpler substances are used to build more
complex ones. Similarly, complex substances are broken down into their simpler
components. Figure 1.2 shows you how one or two types of simple units join to form
complex substances and how complex substances break down into their simpler
units. You will understand this better when you go through Units 2 and 3 of Block I.
The rate at which these reactions proceed is carefully controlled according to the
need of the body. Vitamins, minerals and proteins play a major role in contrnlling
these reactions i.e. they act as regulators.
Fig. 1.2 lnieconvenlon of almplr rnd romplex subutanca
, Basic Conclpts in Social Functionr: Food an.d eating has significant social meaning. Sharing food with
Nutrition-I any other person implies social acceptance. When you share a meal with anyone else,
you are expressing your acceptance of and friendship and respect for that person.
Earlier only perzons enjoying equal status in society ate together. A person would
never share a meal with someone inferior to him in social t e r n . Of course, we
observe considerable change in this respect now particularly in cities and t o m . In a
resdurant, for example, any person can eat irrespective of his social background if
he has the money to pay for the food.
i
Food is an integral part of festivity anywhere in the world. You must have surely
noticed that joyous occasio& such as the birth of a child or a marriage are
celebrated by having feasts and serving delicacies. Festivals such as Diwali,
Dussehra, Pongal, Onam. Lohri, Holi, Christmas and Id are celebrated by having
special and prescribed menus. In all these cases, food sewes the function of bringing
people together.
Food also has a specific significance and meaning in the religious context. Certain
food items such.as fruits, sweets and coconuts are offered to the deity in temples.
Often sweets are prepared at temples and gwdwarae and distributed to devotees as a
benediction or prasad. Further, people of a given religious community share a
common eating pattern. This is because religious texts and practices strongly
recommend some foods while rejecting others. Food thus becomes an integral part of
the social and religious life of people.
P~ycbolodalFundom: We all haw emotional needs s k h AS the need for mcitrity,
love and attention. Food is one way through which those needs are satisfied. When a
mother prepares her child's favourite dish, the child recognizes the fact that she lovm
him enough to remember his likes and dislikes. He appreciates the attention he is
given. As you arc aware, when people share food it serves as a token of friendship
and acceptance. A child quickly accepts foods eaten by his friends and by people he
admires or wants to identify with. He may even accept food he first found distasteful
if he observes his friends enjoying it. Sharing the same food as others around him
and those he considers important in his social sphere gives him a degree of
confidence in himself and reassures him that he will be accepted by others like him.
Food is also closely allied to our emotions. Food often serves as a reward. When a
mother wishes to reward her child for doing well in a test, she may buy him a sweet
or an ice cream. In this manner, that particular food item evokes pleasant feelings in
the mind of the child. On the other hand, certain foods become associated with
sickness such as khichri (a ricedal porridge). This type of food is generally eaten
when a person suffers from fever and may, therefore, not be associated with pleasant
feelings.
Check Your.Pro#re~Exercise 1
1) List the t h m functions of food.
2) Fill in the blanks.
a) The body-building function of food is ~ l a t e dto the presence of ................
b) Energy-giving foods are rickin carbohydrate and/or ..................................
C) ...................
Vitamins and minerals have............................and functions.
3) Read the following statements carefully. Comment in two sentences on whether '
the statement rekites to the physiological or social or psychological functions of
food.
a) Pankaj is celebrating his birthday. He has called his friends to his house for
a party in the evening. His mother has prepared several delicious dishes
particularly those which Pankaj likes.
