Fat
1.Fats are essential part of our body,
accounting for a sixth of our body
weight.
2.The cells and tissues of our body have
fat as an integral part.
3.The vital organs (brain, heart, liver) are
protected by sheath of fat and water.
4.The nerves are also protected by fat
5. A layer of fat beneath the skin acts
as a insulation against cold.
6. The fat around the joints acts as a
lubricant
So, Fat is a
crucial part
of the body composition.

The term fat is used to denote diverse
types of compound characterized by
their insolubility in water, greasy feel
and solubility in some organic solvents
(ether, Chloroform etc.).
•Fat is mainly a fuel source for the
animal or plant in which it is found or
for the animal that eats it.
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•Fats are widely distributed in
nature but in animal they do
not occur in free state.
•They are more usually combine
with protein, vitamin (Fat
soluble), Carbohydrate etc.

Composition of Fat
• Fat are composed of the element:
Carbon, Hydrogen and Oxygen.
• The fat differ from the carbohydrate in
that they are not polymers of repeating
molecular unit.
• They don't form long chain as do Starch,
Cellulose (Carbohydrate).
• They don't contribute structural strength
to plant and animal tissues. 8
• Fats are built by linking together a
number of individual FATTY ACID and
GLYCEROL.
GLYCEROL + FATTY ACID = GLYCERIDE
1 FA
Monoglyceride
2 FA
Diglyceride
3 FA
Triglyceride
=
FAT
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•If TRIGLYCERIDE is composed of same
FATTY ACIDS → Simple TRIGLYCERIDE
•If TRIGLYCERIDE is composed of
different FATTY ACIDS→ Mixed
TRIGLYCERIDE
Edible FATS
are MIXED TRIGLYCERIDE

Fatty Acid
On the basis of saturation (with respect
to Hydrogen), Fatty acid can be classed
as:-
1.Saturated Fatty Acid
2.Unsaturated Fatty Acid
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Fatty Acids
Saturated
Fatty Acids
Unsaturated
Fatty Acids
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Those fatty acids in which all carbon atoms
in the chain contain 2 hydrogen atoms and
thus contain no double bonds are termed
Saturated Fatty acid (carbon-to-carbon
bonds are all single).
Those fat which contain larger portion of
Saturated fatty acids are normally solid at
room temperature
Generally, fat from animal source contain
larger amount of Saturated fatty acid.
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H H H H H H H H H
H - C - C - C - C - C - C - C - C - C -
H H H H H H H H H
COOH
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The fatty acid containing at least one double
bond is known as unsaturated fatty acid and
they are more active than saturated fatty
acid.
Unsaturated fatty acids are those that have some
of the hydrogen atoms missing in carbon chain.
Those fat which contain larger portion of
Unsaturated fatty acids are normally liquid at
room temperature
Generally, fat from plant source contain
larger amount of Unsaturated fatty acid.
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H C C C C C C C C C C C C C C C C C COOH
H
H
H
H
H
H
H
H
H
H
H H H H
H
H H
H
H
H
H
H
H
H
H
H
H
H
H
H
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1
8 7 6 5 4 3 2
10 9
11
13 12
17 16 15 14
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•A fat containing more unsaturated Fatty Acids is
LIQUID at room temperature.
•A fat containing more saturated Fatty Acids is
at room temperature.
Animal Fat contains more saturated Fatty Acids
SOLID
Vegetables Fat contains more unsaturated Fatty Acids
LIQUID
SOLID
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Saturated Fatty Acids
Arachidic acid
Stearic acid
Palmitic acid
Myristic acid
Lauric acid
Capric acid
Caprylic acid
Caproic acid
Butyric acid
Chemical Name
20 Eicosanoic Acid
18 Octadecanoic Acid
16 Hexadecanoic Acid
14 Tetradecanoic Acid
12 Dodecanoic Acid
10 Decanoic Acid
8 Octanoic Acid
6 Hexanoic Acid
4 Tetranoic Acid
No. of Carbon Atom Common Name
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Unsaturated Fatty Acid
4
3
2
1
1
No. of double bond
20 Arachidonic Acid
18 Linolenic Acid
18 Linoleic Acid
18 Oleic Acid
16 Palmitoleic Acid
No. of Carbon Atom Name
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Nutritional classification
of Fatty Acids
•Essential Fatty Acids
•Non Essential Fatty Acids
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Essential Fatty Acids are those which
CANNOT BE SYNTHESIZED by the body
and need to be supplied through diet.
Generally unsaturated Fatty Acids (More
than 1 double bond) are Essential Fatty
Acids.
Non-Essential Fatty Acids are those which
CAN BE SYNTHESIZED by the body and
need not to be supplied through diet.
Generally saturated Fatty Acids are Non
Essential Fatty Acids.
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Poly Unsaturated Fatty Acids
(PUFA)
Those Fatty Acids which have MORE
THAN 1 DOUBLE BOND are called as
Polyunsaturated Fatty Acids (PUFA).
PUFA cannot be synthesized by human
body. So, they should be supplied by
diet. Generally Linoleic and Linolenic
Acids are PUFA.
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Consume oil ,containing
at least
2 Part PUFA
and
1 part Saturated Fatty Acids
(i.e., Vegetable oil + animal fat)
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Function of Essential Fatty Acids
• Deficiency of Essential Fatty Acids
leads to cessation of growth and
development of Scaliness and
Phrynoderma (toad skin).
• Hair is lost from the face and back.
• Blood may appear in the urine.
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Its deficiency affect adversely on:
• Reproduction and Lactation
• Normal Cell Function
• Transport of Cholesterol
• Enzyme system
• Water balance
• Production of Prostaglandin
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Deficiency of Fat
• Deficiency of Essential Fatty Acids
• Deficiency of Fat soluble vitamins
Excess of Fat
• Obesity (Deposition of fat rather than muscle)
• Slow down the digestion and Absorption
of Food
• Cause Ketosis (excess of fat digested
product in blood)
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Sources of Fat
1.Animal Source
2.Plant Source
Animal Source
Milk and Milk products, Egg, Lard, Tallow etc.
Plant Source
Peanut, Sesame, Soybean, Mustard, Safflower,
Cotton seed, Sunflower, Maize, Coconut, Palm,
Walnut, Almond etc.
Cereal, Pulses, Fruit (Except Avocado) ,Veg. are Poor Source
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Sources of PUFA(EFA)
• Rich : Safflower, Cottonseed, soy,
corn, Sunflower, Ground nut,
sesame (50-80% EFA)
• Poor source : Animal Fat
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Sources of EFA
Oil Total EFA g/100g oil
Ghee 2.1
Mustard 22.0
Sesame 40.5
Corn 52.0
Sunflower 52.0
Soybean 57.0
Safflower oil 74.5
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Cholesterol
It occurs in all animal and human tissues.
The white matter of brain contains 14%(db)
The grey matter of brain contains 6%(db)
Body synthesize: 1gm/day
Blood level: 150-300 mg/100 ml
Internal Production = 1 gm/day
Daily consumption = 500 mg
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Cholesterol is required for Vitamin D,
Hormones and Bile acid (useful for fat
digestion).
Cholesterol content of heart, liver,
kidney and egg is quite high. In infancy
and toddler stage (up to 2-3 yrs) new
tissues are formed, especially brain
which needs cholesterol. So, child
should get enough fat up to 5 yrs.
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Sources of Cholesterol
• Present only in Foods of Animal
origin
Cholesterol rich
Egg yolk, organ meat, dairy fat
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Cholesterol Content of Foods
Pork 60
Egg (White) 0
Egg (Yolk) 1400
Egg 500
Milk 11
Cheese 150
Ghee 310
Butter 280
Food mg/100 gm
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Daily Requirements of Fat
20% of Total energy
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Digestion and Absorption
of Fat
Last part of Absorption
Intestine
Glycerol, Fatty
Acids
Fat is
hydrolyzed
First part
of Intestine
Small particles
of fat
Size of Fat
particles reduced
Stomach
Mouth No Action Fat
Site Action Result
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