Fats

1. Fats

2. Why do we need fats?
•Contribute to texture and taste
•Increase palatability of diet
•For meeting the needs of essential
fatty acids (linoleic acid n – 6 and
linolenic acid n – 3)
•Rich source of energy
•Promote absorption of fat soluble
vitamins
•Impart a feeling of fullness and
satisfaction and thus delay onset of
hunger.

3. Essential Fatty Acids
•Queen of Vitamins
•Poly Unsaturated Fatty Acids (PUFA)
•Linoleic acid (C18:2/n-6/PUFA) and
a Linolenic acid (C18:3/n-3/PUFA) –
must be present in a ratio of 5:1 to 10:1
•Omega 6 to Omega 3 (n6 : n3) ratio of 5:1
is desirable

4. Essential Fatty Acids
•High Omega 6 and low omega 3 ratio as
in ground nut, sunflower, safflower oils
(56:1) can predispose to
–free radical injury,
–angiotoxicity,
–impaired immune function,
–reduced glucose tolerance,
–increased platelet aggreagation and
–albuminuria

5. Essential Fatty Acids
•Omega 6 and Omega 3 ratio
–In coconut oil, [PUFA is only 2%] but this
ratio is <5:1 (but more MCTs)
–In ghee it is 3:1
–Mustard oil 1.5:1

6. Essential Fatty Acids
•Omega 3 or n-3
–In coconut oil, [PUFA is only 2%] but this
ratio is <5:1 (but more MCTs)
–In ghee it is 3:1
–Mustard oil 1.5:1

7. Long Chain Fatty Acids
EFAs are converted to LCFAs by a series of
chemical reactions called elongation and
desaturation.
•LCPs from n-6 series derived from linoleic
acid are
–arachidonic acid (ARA) and
–adrenic acid (ADA).
•LCPs from n-3 series derived from alpha
linoleic acid are
–ecosa pentanoic acid (EPA) and
–decosa hexanoic acid (DHA).

8. Long Chain Fatty Acids
EFAs are converted to LCFAs by a
series of chemical reactions called
elongation and desaturation.
•LCPs are the building blocks of brain
lipid.
•Deficiency of LCPs may lead to
comorbid conditions like dyslexia,
dyspraxia and hyperactivity

9. Types of fat
•Visible :
–Fats that are used as such at the
table or in cooking
•Eg: Veg. oils, vanaspathi, ghee,butter
etc.
•Invisible :
–Fats that are present as and integral
components of different foods
•Eg. : cereals, animal foods

10. Component of fat
•Total should be 15 – 30 % and 1-3 %
of calories should be from EFAs
•Avg. Indian foods supply 25-30%
calories as fat. Diets of young children
and adolescents should contain only
25 g/d of fat
•Not more than 10% of energy should
be from essential fatty acids /SFA and
10% should come from MUFA and
10% from PUFA

11. Fatty Acids - Types
•Saturated: Lauric acid (C12), Myristic
acid (C14), Palmitic acid (C16) and
Stearic acid (C18)
–Animal fats
–Short and medium chained saturated FAs
are easily absorbed
–Excess of MCTs can be atherogenic
•Monounsaturated fats:
–Oils from palm, seseme, groundnut,
cotton seed, olive.

12. Fatty Acids - Types
•Polyunsaturated fats:
–Only in plant foods
–All vegetable oils rich in Linoleic (n-6)
– a- linolenic (n-3) is present only in
mustard and soyabean oils and as
invisible oil in legumes/pulses, mustard
and fenugreek seeds (methi) & GLVs
–Fish and fish oils provide biologically
more active form of n-3 linolenic acid

13. Fatty acid compositions
Item SFA % MUFA % PUFA %
n6 n3
Coconut oil 92 6 1.6 0.4
Corn oil 13 25 61 1

Groundnut oil18 49 33 0
Olive oil 14 8 1
Sunflower oil11 20 69 0
Safflolower oil10 13 77 0
Palmolein 40 48 11 1
HVO 76 19 3 2

14. SATURATED MONO
UNSATURATED
POLY UNSATURATED
LINOLEIC (N - 6) LIONOLENIC (N-3)
•Coconut
•Palm kernel
•Ghee
•Butter
•Vanaspathi
•Red palm oil
•Palmolein
•Groundnut
•Ricebran
•Saseme
Low:
• Red palm oil
•Palmolein
Medium:
•Groundnut
•Ricebran
•Seseme
•Mustard
•Soya bean

15. Medium Chain Triglycerides
•C8 - C10 Fatty Acids
•They are absorbed directly into the portal
vein even during fat malabsorption.

16. Cholesterol
•Essential component of body tissues and
lipoproteins
•Forms nearly 0.2 % of body weight
•It has no calorific value
•Hypercholesterolemia – esp. LDL predisposes
to coronary heart disease
•Heredity, smoking, sedentary habit, emotional
stress, hormonal imbalance, diet, diabetes etc.
predispose to hypercholesterolemia.

17. Cholesterol
•Endogenous : Synthesized from 2 carbon
fragments like acetate, acetic acid, acetyl
CoA, etc.
•Exogenous : Derived from food

18. Cholesterol
•Excess cholesterol is converted to bile acids and
excreted into intestine and eliminated as coprosterol
•Dietary fiber reduced cholesterol level
•Cholesterol is present in bound and free forms in a
ration of 1:3
•Bound to esters of fatty acids or lipoprotein (LDL)
cholesterol – 70%
•That bound to alpha lipoprotein is high density
lipoprotein (HDL) cholesterol – 30%
•Small amounts - bound to very low density lipoproteins
(VLDL) and rest to intermediate low density
lipoproteins (ILDL) and very high density lipoproteins
(VHDL)