Unit 1 (introduction to food nutrition & diet

- GAURAV DHAKA
(M.Sc. in H&A, B.Sc. in H&M)
Introduction to
Food Nutrition
and Diet

- Introduction to Nutrition & Diet
- About Calories & Balance Diet
- Daily Caloric Requirements for different age of groups
- Food Groups & their Roles in balance diet.
Contents

What is Nutrition?
• Your body needs energy to do work, and
that energy comes from food.
• Food provides something called Nutrients
to your body.
• Nutrients are substances that provide
energy and materials for growth, repair,
and cell development

Different classes of Nutrients
There are six different kinds of nutrients in foods:
• Proteins (Meat, Beans, Fish)
• Carbohydrates (Wheat, Grains)
• Minerals
• Vitamins
• Fats
• And Water

Proteins
 Large Molecules that contain carbon, hydrogen, oxygen, and nitrogen
 One molecule of protein is made of smaller units (building blocks)
called amino acids
 Your body only needs 20 amino acids to produce thousands of
protein cells!

Carbohydrates
 Main sources of energy for your body.
 The atoms are held together by energy. When the carbohydrate is
broken down, this energy is released for your body.
 There are three types of carbohydrates: sugar, starch and fiber. Sugar
is a simple carbohydrate, and starch and fiber are complex
carbohydrates.

Minerals
 Minerals are inorganic nutrients (nutrients that lack carbon and cause
many chemical reaction in your body).
 About 14 minerals are used in your body.
 Minerals send nerve impulses, build cells, regulate chemical reactions
in cells, and carry oxygen to body cells.

Vitamins
 Vitamins are organic nutrients that are needed in small quantities.
 Vitamins are needed for growth, preventing diseases, and regulating
body functions.
 There are two groups of vitamins: Water Soluble and Fat Soluble.
Water soluble vitamins dissolve in water, so they are not stored in
your body. This means you have to take them daily. Fat soluble
vitamins are dissolved ONLY in fat.

Fats
 Fats are NOT negative. In fact, they provide energy and help your body
absorb vitamins.
 One gram of fat releases almost twice as much as energy than one
gram of carbohydrate does!
 Two group of fats: saturated and unsaturated. Unsaturated fats are
liquid at room temperature, and saturated fats are solids in room
temperature. Also, saturated fats have been associated with high levels
of blood cholesterol.

Water
 Water is essential. Different organisms need different amounts of
water to survive!
 The human body is about 60% water. Your body loses water by
perspiration. When you exhale, you lose water as water vapor. Then,
your nerves system send a signal to your brain for water. This is why
you feel thirsty.

Definition of Diet
 Sum of food consumed by an organism or group
 What you eat everyday!

Calorie
• A calorie is a unit that is used to measure energy.
• A calorie actually measures the energy expenditure and stored energy
Q. What is a calorie in terms of food?
• The Calorie you see on a food package is actually a kilocalorie, or
1,000 calories.
Q. Are Calories Bad?
• Calories aren't bad for you. Your body needs calories for energy. But
eating too many calories — and not burning enough of them off
through activity — can lead to weight gain.

BALANCED DIET
• One which supplies all the nutrients in the right quantity and proportion.
• According to the American Food and Nutrition Board, RDAs are “levels of
intake of essential nutrients that on a basis of scientific knowledge are
adequate to meet the known nutrient needs of all healthy persons.”
• Requirement of an adult sedentary male: 2400 kcal, i.e. 1 unit of energy.

Energy Needs of the Body
Calculated by sum of 3 factors:
a) Basal metabolism.
b) Energy for physical activity.
c) Small amount of additional energy expended during digestion and
absorption of carbohydrates, proteins fats in GIT – specific dynamic
action (SDA) of food.
Energy requirement= BM + Physical Activity + SDA

Calories Needed Each Day
 How many calories you need each day—ENERGY IN— depends on a few things:
• Your age
• Whether you are male or female
• How active you are
 Not Active—
• Not much ENERGY OUT. Does only light activity needed for daily life. For instance, cooking
or walking to the mailbox.
 Somewhat Active—
• Some ENERGY OUT. Does physical activity equal to walking quickly for 1 ½ to 3 miles
(about 30–40 minutes) each day. Plus, does light activity needed for daily life.
 Very Active—
• A lot of ENERGY OUT. Does physical activity equal to running for more than 3 miles each
day (more than 40 minutes). Plus, does light activity needed for daily life.

Calories Needed Each Day (cont.)
These tables give you an idea of how much ENERGY IN your family members need.

Calories Needed Each Day (cont.)

Food Groups & their Roles in
balance diet.

Basic food groups
 Foods can be grouped into categories based on the type or nutrients
that they supply.
 The basic food group classification is based on the physiological role
played by the foods of each group in our body.

Basic food groups (cont.)
- Energy giving foods- cereal grains, fats & oils, sugar and products
made from these foods
- Body building foods – pulses, nuts, oilseeds, milk & milk products,
meat, fish, poultry and products made from these.
- Protective foods – fruits and vegetables which supply vitamins and
minerals

Basic food groups (cont.)
End products is
Glucose
1gm of carbs
produce 4Kcal.
Of energy
Carbohydrates
End Product is
Amino acid
1gm of protein
produce 4Kcal
of energy
Protein
End product is
Fatty acid &
Glycerol
1gm of fat
produce 9kcal
of energy
Fats Vitamins &
Minerals
Vitamins and
mineral is can
digest in their
pure form.
They don’t
produce any
energy but they
helps in cell
growth

FOOD PYRAMID
Foods high in fats & sugars
take only small amount

Balance Diet
33%
33%
15%
12%
7%
Balance Diet
starch
Fruits & vegetables
milk & diary
Meat & fish
fats & sugar

Prepare the Diet Plan of the day
Breakfast Lunch Dinner

GAURAV DHAKA (M.Sc. in H&A, B.Sc. in H&
M)
28

GAURAV DHAKA (M.Sc. in H&A, B.Sc. in H&
M)
29
Q. Define the term nutrition?
Q. What is the relation between food & nutrients?
Q. Define RDA? Name the organisation that decides RDA for Indians?
Q. Why do we consume food?
Q. Explain the relation between nutrients & health?
Q. How much energy is obtained by consuming 3g of carbohydrates, 5g of protein
and 8g of fat?

Unit 1 (introduction to food nutrition & diet

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