Unit 1:
Principles of Nutrition

1. Introduction to the basic nutritional concepts
and terms.
2. Discuss the classification of nutrients.
3. Discuss the scope and importance of
Nutrition and Health
4. Discuss the factors influencing food habits.

basic nutritional concepts
1. Nutrition: is defined as the science of food
and its relationship to health.
• It includes everything that happens to food. It
is the study of nutrients and processes by
which they are used by the body.

2. Dietics:
It is the practical application of the
principles of nutrition which includes planning
of meals for the healthy as well as the sick.
• E.g: eat less meat, do not eat till you feel full,
read labels before you chose to buy,,,,,

3. Food:
anything eaten or drunk, which meets the
needs of tissue building, regulation and
protection of the body and its energy needs.

4. Diet:
refers to whatever people eat, drink each day. It
includes the normal diet people consume and
the diet people consume in groups (Hotel diet)
but will also be modified for the sick as part of
their therapy (Diet therapy).
• It is according to the need of the body i.e:
considering its health conditions

5. Nutrients:
Useful chemical substances derived from the
food by the body are called nutrients.
• Nutrients include:
1. Carbohydrates
2. Lipids
3. Proteins
4. Water
5. Minerals
6. Vitamins

classification of nutrients.
1. Major nutrients (Macronutrients):
Carbohydrates, lipids, proteins and water.
2. Minor nutrients (Micronutrients): Vitamins
and minerals.

The Major Nutrients
• Major nutrients are called Macronutrients.
• Are utilized for energy or are stored as fat.
e.g: Carbohydrates, lipids, proteins and water.

The Minor Nutrients
• It is also called micronutrients (needed in
trace amount).
• do not supply energy or calories, instead they
regulate the metabolism.
E.g: vitamins and minerals ( iron and zinc)

NUTRITION AND HEALTH
• How nutrition is related to health?
• The basic study of nutrition is of primary
importance as:
1. It is fundamental for our own health, and
• 2. It is essential for the health and well being
of our patients and clients from the time of
eating till it is utilized for various functions.

Functions of Nutrition
1. Nutrition helps growth and development
2. Prevents malnutrition
3. Resists infection and
4. Prevents diseases (decrease morbidity and
mortality)

1. Nutrition helps growth and
development
• According to Mental Health Organization in UK:
Nearly two thirds of those who do not report daily mental health problems
eat fresh fruit or fruit juice every day. This pattern is similar for fresh
vegetables and salad. Those who report some level of mental health problem
also eat fewer healthy foods (fresh fruit and vegetables, organic foods and
meals made from scratch) and more unhealthy foods (chips and crisps,
chocolate, ready meals and takeaways).
• A balanced mood and feelings of wellbeing can be protected by ensuring
that our diet provides adequate amounts of complex carbohydrates,
essential fats, amino acids, vitamins and minerals and water.
https://www.mentalhealth.org.uk

2. Prevents malnutrition
• Malnutrition means an undesirable kind of
nutrition leading to ill health. It results in a
lack, excess or imbalance of nutrients in diet.
• It includes under nutrition and over nutrition:
1. Under nutrition is a state of an insufficient
supply of essential nutrients.
2. Over nutrition refers to an excessive intake of
one or more nutrients which creates a stress
in bodily functions.

Causes of malnutrition

• Malnutrition is directly responsible for certain
specific nutritional deficiency diseases like
kwashiorkor, marasmus, vitamin A deficiency,
anaemia, goiter etc.
• Good nutrition is therefore essential for
prevention of disease and promotion of good
health.

Resistance to Infection
• Malnutrition predisposes the body to
infections like tuberculosis,,,,,,,,,.
• Infections in turn aggregate malnutrition and
metabolism.

Mortality and Morbidity
• Thus, food plays a prominent role in providing
physical, mental and social well being which is
the WHO definition of health.
• Thus food reduces incidences of disease
therefore it reduces morbidity rate (death
rate).

Factors influencing food habits:
1. Superstitions
2. Social and cultural factors
3. Religions factors
4. Income
5. Geography/availability
6. Advertising and media

Superstitions and Cultural Factors
• Food habits are handed over from generation
to generation.
• Though these factors have very little or no
scientific basis, people rigidly adhere to them.
• E.g: In many parts of India pregnant women
are not allowed to take papaya and Pineapple
(cause abortion)
• milk with saffron result in a baby with a very
fair complexion

• In parts of Bengal, people believe that
consumption of tongue of goat by children will
make them more talkative.

Religious Belief
• Hindus do not eat beef, and among Hindus some
communities do not eat fruits, onions and garlic.
Many Hindus are vegetarians. To eat meat is to
destroy the seeds of compassion.
• Islamic food laws prohibit the consumption of
“unclean” foods such as swine and animals killed
in a manner that prevents their blood from being
fully drained from their bodies
• Jews do not eat pork and shellfish

Child Rearing Practices
• in India late introduction of weaning foods,
prolonged breastfeeding and the adoption of
commercially produced baby foods
Baby, 4 months, is fed soft food,
fruit or vegetables, AS WELL AS
breastmilk.
http://rehydrate.org/dd/su32.htm
Baby, 9 months, eats mashed food

Geography/Availability
• In the olden days, man would eat what
ever was available to satisfy his hunger.
The food he got was the type he could cultivate in his
locality.
• The nutrition value of natural foods do not vary from
country to country. But there is a great variation in the
composition of prepared
foods such as bread, biscuits, cakes etc., due to variation
in recipes and basic ingredients used in different regions.

Income
• Financial resources determine
the type of food we consume.
• Depending on the availability one selects the
food. People in lower income groups in India
consume, a combination of cereals and
cheaply available green leafy vegetables, roots
and tubers.
• People of higher income groups, can choose
food from all groups irrespective of season.

• Classification, functions, role and
medicinal value of food
• Questions for students for next class
295 - 299

• Understand the concepts of My
Pyramid and apply in daily living
• 299
• One of the most helpful,
easy to use diet planning
tools is the food guide
Pyramid (Fig. 21.1).

• The placement of this five food groups on the
pyramid emphasizes their role in the diet. The
grains that form the base should serve as the
foundation of a healthy diet because breads,
cereals, rice and wheat are high in carbohydrates
and low in fat.
• The grains are followed by fruits and vegetables
which supply the vitamins, minerals and fiber.

• The next level suggests eating smaller
amounts of dairy products as well as meat,
poultry, fish, beans, eggs and nuts. While
foods from these group provides proteins,
calcium, iron, zinc and other nutrients, they
contain large amount of fat and should be
chosen carefully.

• Not considered one of the food groups, the tip
of the pyramid consists of fats, oils and
sweets. They supply lot of fat and/or calories
and few nutrients. These items should be
added to diet cautiously.

What Counts as One Serving?
• According to U.S. Department of Agriculture: The amount of food that
counts as one serving is listed below. If you eat a larger portion, count it as
more than 1 serving.
• Milk, Yogurt, and Cheese 1 cup of milk or yogurt 1¹⁄₂ ounces of natural
cheese 2 ounces of processed cheese Meat, Poultry, Fish, Dry Beans, Eggs,
and Nuts 2-3 ounces of cooked lean meat, poultry, or fish 1¹⁄₂ cup of
cooked dry beans, 1 egg, or 2 tablespoons of peanut butter count as 1
ounce of lean meat
• Department of Health and Human Services Vegetable 1 cup of raw leafy
vegetables ¹⁄₂ cup of other vegetables, cooked, or chopped raw ³⁄₄ cup of
vegetable juice Fruit 1 medium apple, banana, orange ¹⁄₂ cup of chopped,
cooked, or canned fruit ³⁄₄ cup of fruit juice Bread, Cereal, Rice, and Pasta 1
slice of bread 1 ounce of ready-to-eat cereal ¹⁄₂ cup of cooked cereal, rice,
or pasta.
• No specific serving size is given for the fats, oils, and sweets group
because the message is USE SPARINGLY.

• Define calorie.
• The qualitative food requirements are
estimated in term of energy is calories.
• Physiologic calorie or kilocalorie is the unit of
energy, which is the amount of heat necessary
to raise the temperature of one kilogram of
water by 1ºC, from 14.5ºC to 15.5ºC. often
used to measure the energy value of foods.
• 1 kilocalorie = 42 kilojoules

PRODUCTS OF DIGESTION
(Energy Nutrients)
CHO
FATS
PROTEINS
GLUCOSE
FRUCTOSE
GALACTOSE
FATTY ACIDS
GLYCEROL
AMINO
ACIDS
Gastro-
intestinal
System

Calorie Value of Food
• (kilocalories/gm):
Carbohydrates 4
Fat 9
Proteins 4

Definition of BMR
• BMR is defined as the energy expenditure of a
subject at complete physical and mental rest,
awake (and not during sleep) having normal
body temperature and in the post absorption
state (12 hours after the last meal) and 8–12
hours after any significant physical activity.
• You can visit the following page for calculation:
http://www.bmi-calculator.net/bmr-calculator/

Basal metabolism (Basal Metabolic
Rate BMR)
• The BMR is the energy expenditure necessary to
maintain basic physiologic conditions such as:
a. The activity of the heart
b. Respiration
c. Conduction of nerve impulses
d. Ion transport across membranes
e. Reabsorption in the kidney, and
f. Metabolic activity such as synthesis of
macromolecules under standard conditions.

• About 60% or more of the energy the average person
spends goes to support the ongoing metabolic work of the
body’s cells, the basic metabolism. This is the work that
goes on all the time, without conscious awareness.
• E.G: The beating of the heart, the inhaling and exhaling of
air, the maintenance of the body temperature and sending
the nerve and hormonal messages to direct these activities
are the basal procedures that maintain life.
• Basal metabolic needs are surprisingly large. A person
whose total energy expenditure amounts to 2000 calories
per day spends as much as 1200–1400 calories to support
usual metabolism.

• The basal metabolic rate accounts for about
60 to 75% of the calories you burn every day.

Factors Affecting BMR
• BMR differs among different individuals. It
depends on:
a. Variable factors
b. Invariable factors

a. Variable Factors Affecting BMR
a. Nutritional state: BMR is low in starvation and undernourishment
as compared to well fed state. Starvation leads to an adaptive decrease
in BMR, which results from a decrease in
lean body mass.
b. Body size or surface area: The BMR is directly proportional to the
surface area of the subject. Larger the surface area, greater will
be the heat loss and equally higher will be the heat production
and BMR.

• c. Body composition: The BMR is proportionate
to lean body mass (LBM).
• LBM is the body weight minus non-essential
(storage triacyl glycerol) weight. Adipose tissue is
not as metabolically active as lean body mass.
BMR is often expressed as per kilogram of lean
body mass or fat free mass. Therefore, higher the
percentage of adipose tissue in the body lower
the BMR/ kg body weight.

d. Endocrinal or hormonal state: In hyperthyroidism, the BMR
is increased and in hypotheroidism it may be decreased by up
to 40%, leading to weight loss.
e. Environmental temperature or climate: In colder climate
the BMR is higher and in tropical climate the BMR is
proportionately low. Stress, anxiety and disease states,
especially infections, fever, burns and cancer also increases
the BMR.
f. Drugs: Smoking (nicotine), coffee (coffine) and tea
(theophylline) increase the BMR whereas β-blockers tend to
decrease energy expenditure

Invariable Factors Affecting BMR
a. Gender or sex: The BMR of males is slightly higher than that of
females particularly due to:
i. Womens lower percentage of muscle mass (lean body mass)
and higher percentage of adipose tissue (that has lower rate
of metabolism) when compared to men of the same body
weight, and
ii. The difference in sex hormone profile of the two genders.
b. Age: Decrease in BMR with increasing age is probably related
to loss of muscle mass (lean body mass) and replacement of
muscle with adipose tissue that has lower rate of metabolism.

Normal Value of BMR
• BMR values are expressed as K cal or KJ per
square meter of body surface per hour.
In adults BMR for :- Healthy males is 40 K cal (168
KJ) per hour and healthy females is 37 K cal (155 KJ)
per hour.
• This means that the total caloric expenditure in
24 hours to complete basal state is 1800 K cal
(7500 Kj) for adult males and1400 K cal (5859 KJ)
for females assuming that the total bodysurface
across are 1.8 sqm and 1.6 sqm respectively.

Clinical Applications of BMR
a. BMR estimation is used to diagnose thyroid
disorders.
b. BMR is used in calculating food and drugs.

PHYSICAL ACTIVITY
• P 304
• Physical activity is the largest variable affecting energy
expenditure and represents 20–40% of the energy
expenditure.
• The reference man is in the age group of 20- 39 years.
With a weight of 55 Kgs without any disease and with a
capacity to perform 8 hours of moderate activity. When
not engaged in work, a reference man spends 8 hours in
bed and 4 to 6 hours in moving around or in a sitting
position and 2 hours either walking or doing household
activities.

• In the case of a reference woman, the difference
is only in her body weight (45 Kg). Instead of the
physical activity of the
occupation, the woman does household
duties. Other conditions are the same in case
of a reference man.
• The energy expenditure for men and woman is
calculated considering their internal and external
activities. The FAO /WHO expert group (1983)
made the following recommendations (Table
21.1).

• Additional energy is needed for the growth of the foetus,
placenta and tissues during pregnancy. The BMR is also
increased due to increased internal activities.
• Daily 150 K cals during the first semester and 300 K cal
during the rest of the pregnancy is recommended. The
energy cost during the term of pregnancy is 62,500 K cals.
• Additional energy requirements during lactation is for the
secretion of milk. For a normal output of 850 ml per day,
during the first six months, 550 K cal per day is
recommended.

• The activities which demand maximum energy
are in the following order.
• Walking very fast, severe exercise, running,
swimming, labourer’s work, carpentry, metal
and industrial work, walking slowly, laundry
work and ironing.

Energy intake and expenditure

Thermogenic effect of food ?• Thermic Effect of Food (TEF) is the energy
used to digest food and absorb and further
process the nutrients recently consumed.
• It is called diet induced thermogenesis. is
energy spend for digestion, absorption and
storage of food. It is about 5-10% of total
energy expenditure.

• Dudek. G. susan, Nutrition essentials for
Nursing Practice, 7th edition, 2014, Lippincott.
Page 156-160

• Classification of Activities Based on
Occupation Sedantary Male
• Teacher, tailor, priest, executive, shoe maker,
retired personnel, landlords peon.
• Female: Teacher, nurse, house wife, executive.

• Moderate Male
• Fisherman, weaver driver, porter, fitter, turner,
carpenter, agricultural labourer.
• Female : Servant maid, basket maker, beedi
maker.
• Heavy male: Stone cutter, blacksmith,
mineworker, wood cutter.
• Female: Stone cutter etc.

• Understand the role of the nurse
in Nutrition.
• Role of the nurse (appendix 1)
• Questions?

• • Identify the 6 food groups based on the
Omani dietary guidelines
•questions

Food groups
Food servings
• http://wholegrains council.org/files/Oman/
DietaryGuidelines.pdf

Proper food handling and hygienic
practices

Thank You