NCERT Textbook: Clinical Nutrition and Dietetics

 Page 1


Unit I - Work, Livelihood and Career 29
NUTRITION, FOOD SCIENCE 
AND TECHNOLOGY
UNIT II
Chapters.indd   29 8/12/2022   3:30:09 PM
2024-25
Page 2


Unit I - Work, Livelihood and Career 29
NUTRITION, FOOD SCIENCE 
AND TECHNOLOGY
UNIT II
Chapters.indd   29 8/12/2022   3:30:09 PM
2024-25
30
Human Ecology and Family Sciences – Part 1
Our life is centred around food. Food is more than a biological necessity. 
It contributes to our cultural identity, is a part of social and religious 
practices. Food also enables us to realise our creativity, is a symbol of 
hospitality, status and power, among many other things. Our food choices 
have far reaching effects. Food nourishes the body, promotes growth, 
enables it to function and builds resistance to infection. If we eat nutritious 
and wholesome food, our bodies can function optimally. Thus knowledge 
about food and nutrition is essential. 
Food and Nutrition / Food Science and Nutrition is a broad domain 
consisting of several sciences that are distinct yet interrelated. As you 
know, nutrition in??uences our health, well being and quality of life. Are 
you aware that nutrition plays a signi??cant role even before birth and 
that it affects the health of an individual throughout life? Have you ever 
thought of yourself as a biological being, that your body is made up of 
carefully arranged atoms, molecules, cells, tissues and organs? Every cell 
is regularly and continually replaced, some after a few days, some after 
months and some after years, although your external appearance may 
be relatively unchanged. For all these internal and external processes, 
nutrients are required and food is the source of these nutrients. 
However, many people do not have the correct knowledge; some do not 
get adequate food to eat, some overeat, others have wrong food choices 
because of various reasons, thus leading to malnutrition. In India, the 
proportion of undernourished persons has been high, but in recent years, 
prevalence of overnutrition is gradually increasing and many people 
are now suffering from health problems such as obesity, heart disease, 
hypertension, diabetes. Infectious diseases still continue to take their toll. 
Nutrition is the cornerstone for promotion of health as well as prevention 
and management of numerous disease conditions. Trained dietitians/
medical nutrition therapists are required to give advice about diet and 
nutrition to the individual as well as the community. Trained public health 
nutritionists are required to tackle public nutrition and health problems 
at regional, national and international levels, for planning-implementing-
monitoring-evaluating various strategies and programmes.
India is a major producer of fruits and vegetables, milk, etc., but almost 
1/5th to 1/3rd of the produce is wasted. This calls for concerted action 
to prevent spoilage, preserve, process and convert foods into a variety of 
forms. Cost of production in India is less than in many other countries and 
foreign direct investment is high. Therefore, food processing industry has 
been termed as the ‘sunrise sector’ of the Indian economy. Simultaneously 
socio-economic and socio-cultural changes/transitions in the country 
have tremendously increased the demand for ready to eat and processed 
foods. Besides this, the increasing prevalence of disease has necessitated 
Chapters.indd   30 8/12/2022   3:30:09 PM
2024-25
Page 3


Unit I - Work, Livelihood and Career 29
NUTRITION, FOOD SCIENCE 
AND TECHNOLOGY
UNIT II
Chapters.indd   29 8/12/2022   3:30:09 PM
2024-25
30
Human Ecology and Family Sciences – Part 1
Our life is centred around food. Food is more than a biological necessity. 
It contributes to our cultural identity, is a part of social and religious 
practices. Food also enables us to realise our creativity, is a symbol of 
hospitality, status and power, among many other things. Our food choices 
have far reaching effects. Food nourishes the body, promotes growth, 
enables it to function and builds resistance to infection. If we eat nutritious 
and wholesome food, our bodies can function optimally. Thus knowledge 
about food and nutrition is essential. 
Food and Nutrition / Food Science and Nutrition is a broad domain 
consisting of several sciences that are distinct yet interrelated. As you 
know, nutrition in??uences our health, well being and quality of life. Are 
you aware that nutrition plays a signi??cant role even before birth and 
that it affects the health of an individual throughout life? Have you ever 
thought of yourself as a biological being, that your body is made up of 
carefully arranged atoms, molecules, cells, tissues and organs? Every cell 
is regularly and continually replaced, some after a few days, some after 
months and some after years, although your external appearance may 
be relatively unchanged. For all these internal and external processes, 
nutrients are required and food is the source of these nutrients. 
However, many people do not have the correct knowledge; some do not 
get adequate food to eat, some overeat, others have wrong food choices 
because of various reasons, thus leading to malnutrition. In India, the 
proportion of undernourished persons has been high, but in recent years, 
prevalence of overnutrition is gradually increasing and many people 
are now suffering from health problems such as obesity, heart disease, 
hypertension, diabetes. Infectious diseases still continue to take their toll. 
Nutrition is the cornerstone for promotion of health as well as prevention 
and management of numerous disease conditions. Trained dietitians/
medical nutrition therapists are required to give advice about diet and 
nutrition to the individual as well as the community. Trained public health 
nutritionists are required to tackle public nutrition and health problems 
at regional, national and international levels, for planning-implementing-
monitoring-evaluating various strategies and programmes.
India is a major producer of fruits and vegetables, milk, etc., but almost 
1/5th to 1/3rd of the produce is wasted. This calls for concerted action 
to prevent spoilage, preserve, process and convert foods into a variety of 
forms. Cost of production in India is less than in many other countries and 
foreign direct investment is high. Therefore, food processing industry has 
been termed as the ‘sunrise sector’ of the Indian economy. Simultaneously 
socio-economic and socio-cultural changes/transitions in the country 
have tremendously increased the demand for ready to eat and processed 
foods. Besides this, the increasing prevalence of disease has necessitated 
Chapters.indd   30 8/12/2022   3:30:09 PM
2024-25
Unit II - Nutrition, Food Science 
And Technology
31
development of foods for managing disease conditions. This has increased 
the demand for trained personnel who can undertake development, 
manufacture and marketing of various processed foods. 
Increasing number of persons travel outside the home daily for 
education, work, tourism. Also those who live in institutions of various 
kinds such as old age homes, hospitals, orphanages, school and college 
hostels, prisons, ashrams need to be fed daily. Nutritious, wholesome 
and safe food needs to be prepared and catered. This requires expertise 
which can be achieved through appropriate training. With increasing 
tourism, interest in ethnic foods and cuisinology, there is demand for  
quali??ed persons.
However, availability of foods with varying shelf life is not enough. Safety 
of the foods is crucial. ‘Safety culture’ of any organisation is important, be 
it food processing/manufacturing/catering industry. Indian government 
therefore has introduced several legislations and standards of food safety 
from time to time. Ensuring that all consumers have access to safe, good 
quality food, will require persons trained in food quality and safety. 
The ??ve areas dealt in this Unit will acquaint you with basic concepts 
in each of these areas, give you insights about the professions and the 
knowledge and skills you need to acquire for each of these. 
Chapters.indd   31 8/12/2022   3:30:09 PM
2024-25
Page 4


Unit I - Work, Livelihood and Career 29
NUTRITION, FOOD SCIENCE 
AND TECHNOLOGY
UNIT II
Chapters.indd   29 8/12/2022   3:30:09 PM
2024-25
30
Human Ecology and Family Sciences – Part 1
Our life is centred around food. Food is more than a biological necessity. 
It contributes to our cultural identity, is a part of social and religious 
practices. Food also enables us to realise our creativity, is a symbol of 
hospitality, status and power, among many other things. Our food choices 
have far reaching effects. Food nourishes the body, promotes growth, 
enables it to function and builds resistance to infection. If we eat nutritious 
and wholesome food, our bodies can function optimally. Thus knowledge 
about food and nutrition is essential. 
Food and Nutrition / Food Science and Nutrition is a broad domain 
consisting of several sciences that are distinct yet interrelated. As you 
know, nutrition in??uences our health, well being and quality of life. Are 
you aware that nutrition plays a signi??cant role even before birth and 
that it affects the health of an individual throughout life? Have you ever 
thought of yourself as a biological being, that your body is made up of 
carefully arranged atoms, molecules, cells, tissues and organs? Every cell 
is regularly and continually replaced, some after a few days, some after 
months and some after years, although your external appearance may 
be relatively unchanged. For all these internal and external processes, 
nutrients are required and food is the source of these nutrients. 
However, many people do not have the correct knowledge; some do not 
get adequate food to eat, some overeat, others have wrong food choices 
because of various reasons, thus leading to malnutrition. In India, the 
proportion of undernourished persons has been high, but in recent years, 
prevalence of overnutrition is gradually increasing and many people 
are now suffering from health problems such as obesity, heart disease, 
hypertension, diabetes. Infectious diseases still continue to take their toll. 
Nutrition is the cornerstone for promotion of health as well as prevention 
and management of numerous disease conditions. Trained dietitians/
medical nutrition therapists are required to give advice about diet and 
nutrition to the individual as well as the community. Trained public health 
nutritionists are required to tackle public nutrition and health problems 
at regional, national and international levels, for planning-implementing-
monitoring-evaluating various strategies and programmes.
India is a major producer of fruits and vegetables, milk, etc., but almost 
1/5th to 1/3rd of the produce is wasted. This calls for concerted action 
to prevent spoilage, preserve, process and convert foods into a variety of 
forms. Cost of production in India is less than in many other countries and 
foreign direct investment is high. Therefore, food processing industry has 
been termed as the ‘sunrise sector’ of the Indian economy. Simultaneously 
socio-economic and socio-cultural changes/transitions in the country 
have tremendously increased the demand for ready to eat and processed 
foods. Besides this, the increasing prevalence of disease has necessitated 
Chapters.indd   30 8/12/2022   3:30:09 PM
2024-25
Unit II - Nutrition, Food Science 
And Technology
31
development of foods for managing disease conditions. This has increased 
the demand for trained personnel who can undertake development, 
manufacture and marketing of various processed foods. 
Increasing number of persons travel outside the home daily for 
education, work, tourism. Also those who live in institutions of various 
kinds such as old age homes, hospitals, orphanages, school and college 
hostels, prisons, ashrams need to be fed daily. Nutritious, wholesome 
and safe food needs to be prepared and catered. This requires expertise 
which can be achieved through appropriate training. With increasing 
tourism, interest in ethnic foods and cuisinology, there is demand for  
quali??ed persons.
However, availability of foods with varying shelf life is not enough. Safety 
of the foods is crucial. ‘Safety culture’ of any organisation is important, be 
it food processing/manufacturing/catering industry. Indian government 
therefore has introduced several legislations and standards of food safety 
from time to time. Ensuring that all consumers have access to safe, good 
quality food, will require persons trained in food quality and safety. 
The ??ve areas dealt in this Unit will acquaint you with basic concepts 
in each of these areas, give you insights about the professions and the 
knowledge and skills you need to acquire for each of these. 
Chapters.indd   31 8/12/2022   3:30:09 PM
2024-25
Learning Objectives
After completing this chapter, the learner will be able to:
z z understand and describe the signi??cance and scope of clinical 
nutrition and dietetics.
z z describe the role and function of a dietitian/clinical nutritionist/ 
medical nutrition therapist. 
z z explain the knowledge and skills required for a career in clinical 
nutrition and dietetics.
Introduction
Nutrition is the science of food, nutrients and other substances as well as 
their digestion, absorption and utilisation by the body. Nutrition is also 
concerned with the social, psychological and economic aspects of food and 
eating.  It is well known that optimum nutrition is important for providing 
immunity and protection from infection, and to promote recovery from a 
variety of illnesses as well as managing chronic diseases. When nutrient 
intakes are inadequate, the body has dif??culty in maintaining immune 
defences, healing wounds, utilising medications, supporting organ 
functions. Such persons may fall victims to additional complications. 
Nutrition is also important in disease states. In some diseases, nutrition 
plays a major role in management and treatment, and for some it 
Clinical Nutrition 
and Dietetics
Chapter
2
Chapters.indd   32 8/12/2022   3:30:09 PM
2024-25
Page 5


Unit I - Work, Livelihood and Career 29
NUTRITION, FOOD SCIENCE 
AND TECHNOLOGY
UNIT II
Chapters.indd   29 8/12/2022   3:30:09 PM
2024-25
30
Human Ecology and Family Sciences – Part 1
Our life is centred around food. Food is more than a biological necessity. 
It contributes to our cultural identity, is a part of social and religious 
practices. Food also enables us to realise our creativity, is a symbol of 
hospitality, status and power, among many other things. Our food choices 
have far reaching effects. Food nourishes the body, promotes growth, 
enables it to function and builds resistance to infection. If we eat nutritious 
and wholesome food, our bodies can function optimally. Thus knowledge 
about food and nutrition is essential. 
Food and Nutrition / Food Science and Nutrition is a broad domain 
consisting of several sciences that are distinct yet interrelated. As you 
know, nutrition in??uences our health, well being and quality of life. Are 
you aware that nutrition plays a signi??cant role even before birth and 
that it affects the health of an individual throughout life? Have you ever 
thought of yourself as a biological being, that your body is made up of 
carefully arranged atoms, molecules, cells, tissues and organs? Every cell 
is regularly and continually replaced, some after a few days, some after 
months and some after years, although your external appearance may 
be relatively unchanged. For all these internal and external processes, 
nutrients are required and food is the source of these nutrients. 
However, many people do not have the correct knowledge; some do not 
get adequate food to eat, some overeat, others have wrong food choices 
because of various reasons, thus leading to malnutrition. In India, the 
proportion of undernourished persons has been high, but in recent years, 
prevalence of overnutrition is gradually increasing and many people 
are now suffering from health problems such as obesity, heart disease, 
hypertension, diabetes. Infectious diseases still continue to take their toll. 
Nutrition is the cornerstone for promotion of health as well as prevention 
and management of numerous disease conditions. Trained dietitians/
medical nutrition therapists are required to give advice about diet and 
nutrition to the individual as well as the community. Trained public health 
nutritionists are required to tackle public nutrition and health problems 
at regional, national and international levels, for planning-implementing-
monitoring-evaluating various strategies and programmes.
India is a major producer of fruits and vegetables, milk, etc., but almost 
1/5th to 1/3rd of the produce is wasted. This calls for concerted action 
to prevent spoilage, preserve, process and convert foods into a variety of 
forms. Cost of production in India is less than in many other countries and 
foreign direct investment is high. Therefore, food processing industry has 
been termed as the ‘sunrise sector’ of the Indian economy. Simultaneously 
socio-economic and socio-cultural changes/transitions in the country 
have tremendously increased the demand for ready to eat and processed 
foods. Besides this, the increasing prevalence of disease has necessitated 
Chapters.indd   30 8/12/2022   3:30:09 PM
2024-25
Unit II - Nutrition, Food Science 
And Technology
31
development of foods for managing disease conditions. This has increased 
the demand for trained personnel who can undertake development, 
manufacture and marketing of various processed foods. 
Increasing number of persons travel outside the home daily for 
education, work, tourism. Also those who live in institutions of various 
kinds such as old age homes, hospitals, orphanages, school and college 
hostels, prisons, ashrams need to be fed daily. Nutritious, wholesome 
and safe food needs to be prepared and catered. This requires expertise 
which can be achieved through appropriate training. With increasing 
tourism, interest in ethnic foods and cuisinology, there is demand for  
quali??ed persons.
However, availability of foods with varying shelf life is not enough. Safety 
of the foods is crucial. ‘Safety culture’ of any organisation is important, be 
it food processing/manufacturing/catering industry. Indian government 
therefore has introduced several legislations and standards of food safety 
from time to time. Ensuring that all consumers have access to safe, good 
quality food, will require persons trained in food quality and safety. 
The ??ve areas dealt in this Unit will acquaint you with basic concepts 
in each of these areas, give you insights about the professions and the 
knowledge and skills you need to acquire for each of these. 
Chapters.indd   31 8/12/2022   3:30:09 PM
2024-25
Learning Objectives
After completing this chapter, the learner will be able to:
z z understand and describe the signi??cance and scope of clinical 
nutrition and dietetics.
z z describe the role and function of a dietitian/clinical nutritionist/ 
medical nutrition therapist. 
z z explain the knowledge and skills required for a career in clinical 
nutrition and dietetics.
Introduction
Nutrition is the science of food, nutrients and other substances as well as 
their digestion, absorption and utilisation by the body. Nutrition is also 
concerned with the social, psychological and economic aspects of food and 
eating.  It is well known that optimum nutrition is important for providing 
immunity and protection from infection, and to promote recovery from a 
variety of illnesses as well as managing chronic diseases. When nutrient 
intakes are inadequate, the body has dif??culty in maintaining immune 
defences, healing wounds, utilising medications, supporting organ 
functions. Such persons may fall victims to additional complications. 
Nutrition is also important in disease states. In some diseases, nutrition 
plays a major role in management and treatment, and for some it 
Clinical Nutrition 
and Dietetics
Chapter
2
Chapters.indd   32 8/12/2022   3:30:09 PM
2024-25
Unit II - Nutrition, Food Science 
And Technology
33
complements the medical treatment. Nutritional status and support, prior 
to and after illness, play an important role in prognosis, recovery and even 
duration of hospitalisation. Also, illness and disease can result in nutrient 
imbalances even in a person who previously had good nutritional status. 
Thus health and nutrition are intimately interlinked. Poor nutrition 
not only leads to health problems but can also make existing problems 
worse.  The specialised area of nutrition which deals with nutrition during 
illness is ‘Clinical Nutrition’. In recent times, this ??eld is called Medical  
Nutrition Therapy.
Significance
Nutritional care has gained importance worldwide, more so in recent times.  
Health problems/illness/disease and their treatment can affect nutritional 
status in a variety of ways: by impairing a person’s ability to eat and/or 
swallow, by interfering with digestion, absorption and metabolism as well 
as excretion. Even if one function is initially affected, in some individuals, 
if the health problem intensi??es, other body functions may be affected.  
Clinical nutrition focusses on the nutritional management of patients with 
established disease.  
It must be borne in mind that function of any organ/tissue/system 
of the body can be affected due to disease, which can lead to minor and 
acute to major and sometimes, chronic or long lasting problems. In all 
these conditions, it is important to ensure that the person is adequately 
nourished and the person who delivers this service is a trained dietitian/
medical nutrition therapist/clinical nutritionist. The professional clinical 
nutritionist/dietitian uses a systematic and logical approach to the 
nutrition care process, focussing on each person/patient’s unique needs 
and addresses them in an individualistic and holistic manner. The patient 
is the primary focus of the nutritional care process. 
The 20
th
 and 21
st
 centuries have witnessed tremendous advances in 
the ??eld of medicine and pharmacology, enabling us to control many 
communicable and infectious diseases. However, newer diseases such 
as HIV/AIDS have emerged. Prevalence of non-communicable diseases 
such as obesity, heart disease, hypertension and diabetes is not only 
increasing, but these are occurring at a much younger age. In fact, 
India is likely to be the diabetes ‘capital’ of the world. Further, older 
persons require special attention. Thus, the proportion of population 
which requiresnutritional care, support and diet counseling is increasing. 
The clinical nutritionist/medical nutrition therapist plays an important 
role in preventionof diseases and promotion of good health, besides 
recommending therapeutic diets for management of various diseases.
New scienti??c knowledge is being generated about physiological and 
metabolic disturbances in chronic and acute diseases; newer methods of  
Chapters.indd   33 8/12/2022   3:30:10 PM
2024-25