I UNIT 8 DIET IN DISEASE: BASIC
PRINCIPLES
Structure
Introduction
Can Food Cure Disease?
Diet Planning in Disease
8.3.1 How Disease Affects Nutritional Requirements
8.3.2 Influence of Disease on Food Intake and Dietary Pattern
8.3.3 Types of Dietary Modifications
The Concept of Nutritional Care
Your Role in Nutritional and Preventive Health Care
Let Us Sum Up
Glossary
Answers to Check Your Progress Exercises
1 8.1 INTRODUCTION
What is the relationship between diet and disease? You already have many of the
answers. Yes, poor diets can cause disease. Or to put it another way, some diseases
can be cured or controlled by using particular types of diets.
This brings us to the point of trying to understand what is diet therapy and how
should we use the diet to "manage" a disease? In this unit you will find a detailed
discussion on the basic principles in diet therapy and dietary management.
At the end of the unit there is a detailed recapitulation of preventive aspects (Recap 1)
to refresh your memory. The discussion centres around nutrients, their sources and
role in prevention of nutritional deficiency disorders.
\ Objectives
j After studying this unit, you should be able to:
~ ~ -
explain the role of the diet in curing and controlling diseases
discuss basic principles of diet planning in disease
identify your role in nutritional care in the community
- - ~ -
4.2 CAN FOOD CURE DISEASE?
ancient times we, in India, have endowed food with magical qualities. In the
times, food was associated with divine attributes. This tradition was prevalent
societies as well-ancient Egypt for example.
blindness was a well recognised disease in ancient Egypt. The cure suggested
apply to the eyes juice squeezed from cooked liver! The ancient Greeks
that the patient eat cooked liver in addition to applying cooked liver oil
is a good example of how man discovered the healing powers of food-perhaps
Later these patterns became well established and were described
texts. The astonishing fact is their proven value in treating disorders
by lack of food and nutrients.
\
An ther dramatic episode in man's search for a cure is the story of scurvy. Scurvy is
aau ed by vitamin C deficiency. Fresh herbs, lemons, oranges and other citrus fruits
wer found to be very effective in preventing and controlling scurvy.
,Dietary Management of Disease These episoaes in the history of man's battle against disease clearly illustrate the fact
that food can cure certain types of diseases. It is quite evident, however, that the
diseases which can be cured by food or nutrient concentrates are caused by
deficiency of particular nutrients. The disorders a& cured by giving food sources rich
in the nutrient that is otherwise lacking in the diet
This does not mean that food and the nutrients it contains can cure all diseases.
However there is no doubt that food can help to control several ailments. Diabetes is
a common example. Mild cases of diabetes which manifest themselves in middle
aged persons can usually be conlrolled using diet alone.
Phenylketonuria (PKU) is a genetic disease caused by inability of the body to utilize
the amino acid phenylalanine, As you are aware, amino acids are the building blocks
of proteins. Young children with PKU have to be given a diet which is almost free
of phenylalanine. Otherwise they become mentally retarded. This shows us that PKU
cannot be cured but dietary measures can keep it in check.
There are several other diseases which cannot be cured by food. Diseases caused by
bacteria and viruses are obviously treated with antibiotics or sulpha preparations.
Even in such cases good food is essential to prevent the patient from becoming weak.
It also promotes quick recovery.
You will come across several other examples in this block to illusvate the role of
food in the treatment of disease. From the previous discussion you would have
realized that diseases can be of three typs:
I. Diseases or disorders caused by nuuient deficiency.
11. Diseases which have several causes some of which are food and nutrient-related.
111. Diseases which have no direct food or nutrient-related cause.
Giving foods and nutrients in concentrated form is effective therapy for those
diseases we have mentioned in the fist categoryftype. Food and diet plays an all
important role in the treatment of these disorders.
Diseases in the second category include diabetes and coronary heart disease (CHD).
Consumption of excessive amounts of sugar and refined carbohydrates can precipitate
diabetes in individuals who are already genetically predisposed. Similarly
consumption of diets containing excessive amounts of fats particularly saturated fats
and cholesterol is believed to be a cause of CHD and the underlying process of
narrowing of arteries by deposition of fat (atherosclerosis).
In the case of these diseases diet cannot cure disease. It can only help to check the
progress of the disease process and also to prevent complications. Diet therapy,
therefore, helps patients to lead a full life. Without it the disease can become
uncontrollable irrespective of whether the patient is also prescribed drugs or not. In
fact mild cases can be controlled by diet alone, as we mentioned earlier.
Infectious diseases are good examples of the third category. Some of these may be
transmitted through food. However, food is not the direct cause. Treatment of these
diseases usually do include a greater or lesser degree of diet therapy. For example, a
febrile infectious disease (disease associated with fever, as you know) would require
giving the patient additional energy and protein-rich foods in a suitable form. This
would depend on whether the fever is chronic as in the case of tuberculosis or acute
as in typhoid. You will study more details about these conditions later in this block
(Unit 9). Here, we will only emphasize that a suitable diet is very important in
helping the person to recover from infectious diseases.
8.3 DIET PLANNING IN DISEASE
A diet for a patient suffering from a specific disease is'called a therapeutic diet.
Therapeutic diets are adaptations of the normal or regular diet.
At this point you may wonder-why does the diet have to change in certain disease
conditions? What types of changes are frequently made? And finally, do we need to
make dietary modifications only in the case of persons suffering from a disease or
also for those who are likely to suffer from a disease (i.e. individuals who are at
risk)?
, You justneed wait a little while for the answers to these cmcia questions. TO
the jnfomali0n SySteRlaticdLy. we will discuss Ule issue with respect m:
Dbt in Dlse~se:Baslc Principles
How disease affects nutritiond requirements
Influence of disease on food intake and dietary patterns
Types of dietary modifications
8.3.1 How Disease Affects Nutritional Requirements
Several diseases bring about changes in the body's need for nutrients. Why? The
reason is usually a change in metabolic or physiological processes as well as
accompanying changes in the structure and/or function of specific organs and tissues.
A few examples will help to clarify these aspects.
Example A: Gopi is suffering fran nephritis. (Nephritis is an inflammatory condition
of the kidneys i.e. the kidney cells or nephrons). Her kidney function is affected and
she is unable to excrete electrolytes such as sodium and chloride resulting in their
accumulation in the body.
I Example B: Kartik completed his 45th birthday last week. He has been suffering
from diabetes for five years now. Due to lack of insulin (or lack of functional insulin)
! his body is unable to utilize carbohydrates efficiently.
Example C: Raju is suffering from typhoid. He is extremely weak and has lost a lot
of weight. High fever continues to trouble him.
( Can you predict which nutrient requirements will be influenced in each case?
In nephritis the inability of the kidneys to function effectively result in accumulation
of water, electrolytes, urea and other waste products in blood and other tissues. So in
Gopi's case, intake of sodium and protein has to be resuicted. This is because
I
breakdown of protein results in production of urea which must be excreted.
I Carbohydrates are emphasized. Kartik's diet, on the other hand, should not include
carbohydrates such as sugar but complex carbohydrates (such as fibre and starch)
need to be emphasized. Fat usually is restricted and should be of the unsaturated
type.
Raju has high fever. Fever pushes up the metabolic rate. If the metabolic rate
increases, energy needs will also increase. In other words, Raju would need a diet
which supplies more energy. He is also losing weight because of loss of tissue. How
is this to be replaced? Obviously by giving more protein.
We have used these examples to indicate just some of the changes in natrient needs
caused by these diseases. These are not the only dietary modifications required in
diseases such as diabetes, typhoid and nephritis. Several others such as modification in
texture and inclusion/exclusion of specific foods are required.
In general we can say that diseases that cause the loss of a particular nuuient would
increase the need for that nutrient. On the other hand, if a disease results in
accumulation of a particular nuuient. the intake of that nutrient is usually restricted or
it may be given in a different form.
One point that we must emphasize here is the fact that sometimes the disease process
does not alter nuuient needs and yet we may need to make dietary modifications. We
will take a closer look at this aspect in the subsequent discussion.
( Remember, however, that requirements depend on
nutritional status (i.e. condition of health as influenced by intake of nutrients)
) modification in activity
( increased or decreased metabolic demands made by the illness and
efficiency of digestive, absorptive and excretory mechanisms
, 91
check Your Rogrc~.Exercise 1
okw ~ . 01 ar.
~ ~ ~ ~ t
11 L t a ~ as~ as completely c o n t d most disas
DO you a p with this m m e n t ? -
Give reasons for your answer.
...........................................
...........................................................
............................................
..........................................................
.......................................................................................................
.......................................................................................................
......................................................................................................
......................................................................................................
2) Resd ~e following statements carefully. Indicate whether e g h is m e or false.
Correct the false statements.
a) In fever energy needs go up and hence need for B complex vitamins go
down.
.......................................................................................................
b) Dietary modifications are not required in the case of all diseases.
C) A patient who is on bed rest will have lower caloric requirements provided
no other factors specific to his disease condition intervene e.g. fever.
8.3.2 Influence of Disease on F w d Intake and Dietary Pattern
The disease process very often influences both the quality and quantity of the diet.
Further changes in meal frequency and other aspects of the dietary pattern may be
requkd.
Disease may cause the patient to:
lose appetite and therefore eat less
feel more hungry and therefore eat more . -
have problems with digestion or absorption of food or specific nutrients leading
to changes in the types of foods which can be tolerated as also frequency of
feeding.
Let us elaborate a little more on how illness modifies food acceptance. Some diseases
result in marked anorexia or lack of appetite.'Conditions associated with jaundice are
notable examples. On the other hand, hormonal imbalances can make a person eat
excessively resulting in overweight and obesity. Also specific foods may be poorly
tolerated and lead to distention or flatulence (gas production). Others may irritate the
gastrointestiond tract. A good example is the irritating effect of high fibre foods in
conditions where the gastrointestinal tract is inflamed.
Now let us study the major therapeutic modifications of the normal diet. What are
the types of quantitative and qualitative changes generally made? Read on to find out.
8.3.3 Types of Dietary Modifications
Our previous discussion has highlighted the fact that dietary modifications need to be
made in the case of several diseases. We must remember that therapeutic diets are
always modified versions of normal diets.
PRINCIPLES
Structure
Introduction
Can Food Cure Disease?
Diet Planning in Disease
8.3.1 How Disease Affects Nutritional Requirements
8.3.2 Influence of Disease on Food Intake and Dietary Pattern
8.3.3 Types of Dietary Modifications
The Concept of Nutritional Care
Your Role in Nutritional and Preventive Health Care
Let Us Sum Up
Glossary
Answers to Check Your Progress Exercises
1 8.1 INTRODUCTION
What is the relationship between diet and disease? You already have many of the
answers. Yes, poor diets can cause disease. Or to put it another way, some diseases
can be cured or controlled by using particular types of diets.
This brings us to the point of trying to understand what is diet therapy and how
should we use the diet to "manage" a disease? In this unit you will find a detailed
discussion on the basic principles in diet therapy and dietary management.
At the end of the unit there is a detailed recapitulation of preventive aspects (Recap 1)
to refresh your memory. The discussion centres around nutrients, their sources and
role in prevention of nutritional deficiency disorders.
\ Objectives
j After studying this unit, you should be able to:
~ ~ -
explain the role of the diet in curing and controlling diseases
discuss basic principles of diet planning in disease
identify your role in nutritional care in the community
- - ~ -
4.2 CAN FOOD CURE DISEASE?
ancient times we, in India, have endowed food with magical qualities. In the
times, food was associated with divine attributes. This tradition was prevalent
societies as well-ancient Egypt for example.
blindness was a well recognised disease in ancient Egypt. The cure suggested
apply to the eyes juice squeezed from cooked liver! The ancient Greeks
that the patient eat cooked liver in addition to applying cooked liver oil
is a good example of how man discovered the healing powers of food-perhaps
Later these patterns became well established and were described
texts. The astonishing fact is their proven value in treating disorders
by lack of food and nutrients.
\
An ther dramatic episode in man's search for a cure is the story of scurvy. Scurvy is
aau ed by vitamin C deficiency. Fresh herbs, lemons, oranges and other citrus fruits
wer found to be very effective in preventing and controlling scurvy.
,Dietary Management of Disease These episoaes in the history of man's battle against disease clearly illustrate the fact
that food can cure certain types of diseases. It is quite evident, however, that the
diseases which can be cured by food or nutrient concentrates are caused by
deficiency of particular nutrients. The disorders a& cured by giving food sources rich
in the nutrient that is otherwise lacking in the diet
This does not mean that food and the nutrients it contains can cure all diseases.
However there is no doubt that food can help to control several ailments. Diabetes is
a common example. Mild cases of diabetes which manifest themselves in middle
aged persons can usually be conlrolled using diet alone.
Phenylketonuria (PKU) is a genetic disease caused by inability of the body to utilize
the amino acid phenylalanine, As you are aware, amino acids are the building blocks
of proteins. Young children with PKU have to be given a diet which is almost free
of phenylalanine. Otherwise they become mentally retarded. This shows us that PKU
cannot be cured but dietary measures can keep it in check.
There are several other diseases which cannot be cured by food. Diseases caused by
bacteria and viruses are obviously treated with antibiotics or sulpha preparations.
Even in such cases good food is essential to prevent the patient from becoming weak.
It also promotes quick recovery.
You will come across several other examples in this block to illusvate the role of
food in the treatment of disease. From the previous discussion you would have
realized that diseases can be of three typs:
I. Diseases or disorders caused by nuuient deficiency.
11. Diseases which have several causes some of which are food and nutrient-related.
111. Diseases which have no direct food or nutrient-related cause.
Giving foods and nutrients in concentrated form is effective therapy for those
diseases we have mentioned in the fist categoryftype. Food and diet plays an all
important role in the treatment of these disorders.
Diseases in the second category include diabetes and coronary heart disease (CHD).
Consumption of excessive amounts of sugar and refined carbohydrates can precipitate
diabetes in individuals who are already genetically predisposed. Similarly
consumption of diets containing excessive amounts of fats particularly saturated fats
and cholesterol is believed to be a cause of CHD and the underlying process of
narrowing of arteries by deposition of fat (atherosclerosis).
In the case of these diseases diet cannot cure disease. It can only help to check the
progress of the disease process and also to prevent complications. Diet therapy,
therefore, helps patients to lead a full life. Without it the disease can become
uncontrollable irrespective of whether the patient is also prescribed drugs or not. In
fact mild cases can be controlled by diet alone, as we mentioned earlier.
Infectious diseases are good examples of the third category. Some of these may be
transmitted through food. However, food is not the direct cause. Treatment of these
diseases usually do include a greater or lesser degree of diet therapy. For example, a
febrile infectious disease (disease associated with fever, as you know) would require
giving the patient additional energy and protein-rich foods in a suitable form. This
would depend on whether the fever is chronic as in the case of tuberculosis or acute
as in typhoid. You will study more details about these conditions later in this block
(Unit 9). Here, we will only emphasize that a suitable diet is very important in
helping the person to recover from infectious diseases.
8.3 DIET PLANNING IN DISEASE
A diet for a patient suffering from a specific disease is'called a therapeutic diet.
Therapeutic diets are adaptations of the normal or regular diet.
At this point you may wonder-why does the diet have to change in certain disease
conditions? What types of changes are frequently made? And finally, do we need to
make dietary modifications only in the case of persons suffering from a disease or
also for those who are likely to suffer from a disease (i.e. individuals who are at
risk)?
, You justneed wait a little while for the answers to these cmcia questions. TO
the jnfomali0n SySteRlaticdLy. we will discuss Ule issue with respect m:
Dbt in Dlse~se:Baslc Principles
How disease affects nutritiond requirements
Influence of disease on food intake and dietary patterns
Types of dietary modifications
8.3.1 How Disease Affects Nutritional Requirements
Several diseases bring about changes in the body's need for nutrients. Why? The
reason is usually a change in metabolic or physiological processes as well as
accompanying changes in the structure and/or function of specific organs and tissues.
A few examples will help to clarify these aspects.
Example A: Gopi is suffering fran nephritis. (Nephritis is an inflammatory condition
of the kidneys i.e. the kidney cells or nephrons). Her kidney function is affected and
she is unable to excrete electrolytes such as sodium and chloride resulting in their
accumulation in the body.
I Example B: Kartik completed his 45th birthday last week. He has been suffering
from diabetes for five years now. Due to lack of insulin (or lack of functional insulin)
! his body is unable to utilize carbohydrates efficiently.
Example C: Raju is suffering from typhoid. He is extremely weak and has lost a lot
of weight. High fever continues to trouble him.
( Can you predict which nutrient requirements will be influenced in each case?
In nephritis the inability of the kidneys to function effectively result in accumulation
of water, electrolytes, urea and other waste products in blood and other tissues. So in
Gopi's case, intake of sodium and protein has to be resuicted. This is because
I
breakdown of protein results in production of urea which must be excreted.
I Carbohydrates are emphasized. Kartik's diet, on the other hand, should not include
carbohydrates such as sugar but complex carbohydrates (such as fibre and starch)
need to be emphasized. Fat usually is restricted and should be of the unsaturated
type.
Raju has high fever. Fever pushes up the metabolic rate. If the metabolic rate
increases, energy needs will also increase. In other words, Raju would need a diet
which supplies more energy. He is also losing weight because of loss of tissue. How
is this to be replaced? Obviously by giving more protein.
We have used these examples to indicate just some of the changes in natrient needs
caused by these diseases. These are not the only dietary modifications required in
diseases such as diabetes, typhoid and nephritis. Several others such as modification in
texture and inclusion/exclusion of specific foods are required.
In general we can say that diseases that cause the loss of a particular nuuient would
increase the need for that nutrient. On the other hand, if a disease results in
accumulation of a particular nuuient. the intake of that nutrient is usually restricted or
it may be given in a different form.
One point that we must emphasize here is the fact that sometimes the disease process
does not alter nuuient needs and yet we may need to make dietary modifications. We
will take a closer look at this aspect in the subsequent discussion.
( Remember, however, that requirements depend on
nutritional status (i.e. condition of health as influenced by intake of nutrients)
) modification in activity
( increased or decreased metabolic demands made by the illness and
efficiency of digestive, absorptive and excretory mechanisms
, 91
check Your Rogrc~.Exercise 1
okw ~ . 01 ar.
~ ~ ~ ~ t
11 L t a ~ as~ as completely c o n t d most disas
DO you a p with this m m e n t ? -
Give reasons for your answer.
...........................................
...........................................................
............................................
..........................................................
.......................................................................................................
.......................................................................................................
......................................................................................................
......................................................................................................
2) Resd ~e following statements carefully. Indicate whether e g h is m e or false.
Correct the false statements.
a) In fever energy needs go up and hence need for B complex vitamins go
down.
.......................................................................................................
b) Dietary modifications are not required in the case of all diseases.
C) A patient who is on bed rest will have lower caloric requirements provided
no other factors specific to his disease condition intervene e.g. fever.
8.3.2 Influence of Disease on F w d Intake and Dietary Pattern
The disease process very often influences both the quality and quantity of the diet.
Further changes in meal frequency and other aspects of the dietary pattern may be
requkd.
Disease may cause the patient to:
lose appetite and therefore eat less
feel more hungry and therefore eat more . -
have problems with digestion or absorption of food or specific nutrients leading
to changes in the types of foods which can be tolerated as also frequency of
feeding.
Let us elaborate a little more on how illness modifies food acceptance. Some diseases
result in marked anorexia or lack of appetite.'Conditions associated with jaundice are
notable examples. On the other hand, hormonal imbalances can make a person eat
excessively resulting in overweight and obesity. Also specific foods may be poorly
tolerated and lead to distention or flatulence (gas production). Others may irritate the
gastrointestiond tract. A good example is the irritating effect of high fibre foods in
conditions where the gastrointestinal tract is inflamed.
Now let us study the major therapeutic modifications of the normal diet. What are
the types of quantitative and qualitative changes generally made? Read on to find out.
8.3.3 Types of Dietary Modifications
Our previous discussion has highlighted the fact that dietary modifications need to be
made in the case of several diseases. We must remember that therapeutic diets are
always modified versions of normal diets.
