2016-03-03 Human Nutrition Fat AZK

8/19/2019 2016-03-03 Human Nutrition Fat AZK

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+Digestie n!t"ients

Ma#"$n!t"ients

Carbohydrates

Proteins

Fat

Mi#"$n!t"ients

Vitamins

Minerals

Essential n!t"ients

Nutrients that can not be produced by the body



+Int"$%!#ti$n & Fats

Provide: The most concentrated form of energy in the diet ( !cals"g# $ssential nutrients (essential fatty acids ($%&s#

' inta!es: ) 3'( $) ene"g*

' D*V: 3'( $) ene"g*

De)initi$n &ctual or potential esters $) )att* a#i%s Ins$l!le in ate" - s$l!le in n$n $la" s$lents

(eg: chloroform+ ether#



+ Fats in )$$%

,Visible- fat ( ./0#

,1nvisible"2idden- fat (./0#

3utter Margarine Vegetable oil Lard (dripping# Cream

%at on meat

Chic!en s!in 3iscuits

and Ca!es

4ausages4ausages

Pi55a

%ast food%ast food

Nuts



+ F!n#ti$ns $) )at in the $%*

67 $nergy store87 Thermal insulator

97 $lectrical insulator

7 4teroid hormone precursor

.7 3ile acid manufacture

;7 $ssential fatty acids ($%&s#

<7 Carrier of fat soluble vitamins (&+D+$+#



+ T*es $) lii%s

/te"$lsh$leste"$lF$$%s1

Ani2al(Cholesterol in meat+ dairy#

Plants

(plant stanols and sterols#H$"2$nes

T"igl*#e"i%es/t$"age )atF$$%s1

'( $) )$$%s

Ph$sh$lii%sFat in #ell alls

F$$%s1 e2!lsi)ie"s,eggs, lie", ean!ts

& 3

C D



+ /te"$ls

4terols have as their core a fused four ring structure (the &+ 3+ C+ and D rings#7

Various groups added to the core structure generate other important molecules7

& 3

C D

= %ound in plant and animal foods= h$leste"$l is found in ani2al )$$%s $nl*



/te"$ls



+T"igl*#e"i%es

Dietary fats are mostly T>s The 9 fatty acids are a mi?ture of different types of %&

$ach T> is made up of a mi?ture of %&s

The type of %& gives the fat its properties





P"esen#e $)

%$!le $n%s



FAs& N$2en#lat!"e





+ F$"2ati$n $) Ts



+ T*es $) )att* a#i%

%atty acids differ in number of carbon hydrogen atoms

Ehen hydrogen atoms are missing+ carbon atoms form double

bonds

67 4aturated fatty acids (4%&# B no double bonds

87 Monounsaturated fatty acids (M'%&# B 6 double bond (2 missing Hatoms)

97 Polyunsaturated fatty acids (P'%&# B 8 or more double bonds (four or

more missing H atoms)



+ Ts 2a* hae %i))e"ent t*es $) FAs





+FA 2elting $ints 5MP6

Longer the %& chain B 2igher melting point (MP#

More saturated B 2igher MP

2ydrogenation:4traightens unsaturated %&-s alloEs tighter pac!ing

raises MP



+ FA 2elting $ints



+



+ /at!"ate% )att* a#i%s

Fatty Acids

• Length of carbon chain

Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning

Stearic acid – 18-carbon, saturated

Simplified structure

&n e?ample:

/TERI a#i% 7810 (6F carbon atoms+ no double bonds#Most common saturated %&G found in all plant and animal fats.



+ /FAs

Palmitic acid stearic acid hard fats such as butter+ lard+ suet+ cocoa butter

Myristic acid butter and coconut oil

3utyric acid small amounts in butter and mil! contributes to their taste+

released Ehen fats become rancid



+$22$n /FAs



+ /FA an% health

2igh inta!e of 4%&s have been associated Eith:

*aised blood cholesterol level (LDL#+ a ris! factors for CVD

The development of insulin resistance dyslipidaemia (abnormal blood fat

levels# as part of the ,Metabolic 4yndrome- (a cluster of ris! factors for

CVD# that is also associated Eith increased ris! of type 8 diabetes

>uidelines recommended reducing overall dietary fat consumption to 9.0

of total energy inta!e+ and specifically+ saturated fat to 6/0 of total energy

inta!e



<ii% #$ntent $) sele#te% )$$%s



+<ii% #$ntent $) sele#te% )$$%s



+ Unsat!"ate% FAs

= The configuration for double bond is almost alEays cis

The bent structure is common for unsaturated %as

= LiKuid at room temperature

= Most commonly+ from vegetable origin

= Their melting point (MP#:= increases Eith increasing chain length= decreases Eith degree of unsaturation

hen a fatty acid is unsaturated and has a short chain length+

it in#"eases the )l!i%it*



+ M$n$ !nsat!"ate% FA=s1 5MUFA6

&n e?ample:

O<EI a#i% 7817n& (6F carbon atoms+ 6 double bonds#%ound in olive oilG may have health benefits

(Mediterranean diet#



+

omega end alpha end

ne double bond

H H H H H H H H H H H H H H H O

H-C--C--C--C--C--C--C--C--C=C--C--C--C--C--C--C--C--C-OH

H H H H H H H H H H H H H H H H H

M$n$ !nsat!"ate% FA=s1 5MUFA6



+



+PUFA

&n e?ample:

<INO<EI a#i% 781; 5n&>6

(6F carbon atoms+ 8 double bonds#

Most common P'%& found in corn+ peanut+ soybean many plant

oils



+P$l*!nsat!"ate% Fatt* A#i%

/t"!#t!"e

omega end alpha end

6 double bonds

H H H H H H H H H H H H H O

H-C--C--C--C--C--C=C--C--C=C--C--C--C--C--C--C--C--C-OH

H H H H H H H H H H H H H H H H H



% tt id t i l t d f d



%atty acids types in selected foods



+





+Cis / Trans

Cis1 *oth Hydrogens on the same side of dou$le $ond Molecule has a !in!Can not be densely pac!ed

'nsaturated is %&-s found in oils

Trans: Hydrogens on different sides of dou$le $ond

No !in!ccurs naturally+ in small amounts+ due to fermentationCan be densely pac!ed (hence+ solid vegetable fat#



+ Cis / Trans





+

Most unsaturated fatty acids have their double bonds

in the cis form



H*%"$genati$n #hanges cis t$ trans



+



+ H*%"$genati$n1

Converts unsaturated oils tos$li% egetale )at byconverting cis bonds to

trans Can be pac!ed together

more closely

Creates vegetable fats







+



+ $nsistent )in%ing1T"ans&FAs )$"2 ass$#iate% ith "aise% lii%s ? the

%eel$2ent $) @D

http:""EEE7sacn7gov7u!"pdfs"sacnOtransOfattyOacidsOreport7pdf

E ti l F tt A i%



+ Essential Fatt* A#i%s

Position of double bond counted from the methylBend

eg: nB;: 6st double bond is on ;th carbon

&nimals can not insert double bonds close to the methylBend

%atty acids Eith double bonds at nB9 nB; are the essential fatty

acids ($%&s#

%as that humans and other animals must ingest because the

body reKuires them for good health but cannot synthesi5e them7

T f tt id ! t b ti l f h l h li l i



TEo fatty acids are !noEn to be essential for humans: alphaBlinolenic

acid (an omegaB9 fatty acid# and linoleic acid (an omegaB; fatty acid#7

Conditionally essential: they can become essential under some

developmental or disease conditionsG e?amples include

docosahe?aenoic acid (an omegaB9 fatty acid# and gammaBlinolenic

acid (an omegaB; fatty acid#7



+ E ti l F tt A i% 5EFA 6



+ Essential Fatt* A#i%s 5EFAs6

O2ega&3 O2ega >

&<in$leni# a#i% <in$leni# a#i%

DHA EPA A"a#hi%$ni# A#i%

(docosahe?anoic (eicosapentaenoic

acid# acid#



+ n > - $2ega > 5B >6



+ n&> - $2ega > 5B&>6

%ound in plant oils eg: +inoleic acid 18:2 (n!') *eKuirement: 6 B80 of energy (8 B g"day#

&rachidonic acid (C8/:# is the main %& in cellmembranes

Produces eicosanoids in response to trauma

these cause inflammation blood clotting aroundtrauma site prevent blood clots in arterial Ealls

+



+

+



+

+ Ei#$san$i%s



+ Ei#$san$i%s

2ormoneBli!e substancesG act on the tissues Ehere they are

produced

6# Prostaglandin (P>$8# B pro inflammatory

(acts on ,* #

8# Thrombo?ane (T&8# B pro thrombotic

(acts on platlets#

9# Prostacyclin (P>18# B anti thrombotic

(acts on $lood vessel alls)

+



+

+ n&3 & $2ega 3 5B&36



+ n&3 & $2ega 3 5B&36

%ound in plant oils and oily fish fish oils

eg: -!+inolenic acid 18:3 (n!3)

*eKuirement: /7. of energy (6 g"day#

ill create inactive $1C4&N1D4

+ n&3 & $2ega 3 5B&36



+ n&3 & $2ega 3 5B&36

Parent %&: QBLinolenic acid (C6F:9+ nB9#

$icosapentaenoic acid ($P&# (C8/:.+ nB9#

6# Prostaglandin (P>$9# .nactive

8# Thrombo?ane (T&9# .nactive

9# Prostacyclin (P>19# /ctive

+



+EPA replaces aracidonic acid in cell membranes

inactive P>$8 T&8

*educed inflammation and blood clotting

Cod liver oil $vening Primrose il

*ich in $P&

&nti inflammatory

+ 9l!e"



+ 9l!e"

In!it 5EsCi2$s6 eat Ehale blubber

(rich in $P&#

9lee%ing ti2e

1nuit 6/ minutes

Non 1nuit 9 minutes



+



+

Asi"in ( other C inhibitors# stop &&

producing P>$8 T&8

Asi"in ? EPA

R reduce inflammation blood clotting

@D patients encouraged to eat oily fish

ta!e aspirin

+



+

+



+DHA Decosahexanoic acid C22:6 (n-3 6

Needed for brain function visual response:

9"ainB phospholipids (8/0 of total# e*e B retinal

phospholipids (./0 of total#

&dults can ma!e $P& D2& from QBLinolenic acid

PreBterm infants need preformated D2&

D2& added to formula mil!

$P& D2& found in fish oils

+



+

+



+

+



+

+



+



+



+Oe"ie $) li$"$tein 2eta$lis2

*obert &7 2egele 0ature evies enetics 70+ 6/B686 (%ebruary 8//#

CM carry:T>

Chol

Vitamins

+

https://www.youtube.com/watch?v=O1XToe78zxs

https://www.youtube.com/watch?v=O1XToe78zxs



+Fat intaCes in UK %iet 5NDN/ ;0776

Dietary Referencea!ue

"verage inta#e inadu!ts

Total fat!" of food energy#i$e$ e%cluding alcohol&

!" in men'$'" in (omen

Saturated fatty acids 11" of food energy1)$8" in men1)$*" in (omen

Trans fatty acids +elo( )" of food energy ,$" in men and (omen

Total Cis polyunsaturates *$!" of food energy*$1" in men*$)" in (omen

Cis n- polyunsaturates.inimum inta/e ,$)" offood energy

1" in men1$1" in (omen

Cis n-* polyunsaturates .inimum inta/e 1" offood energy0

!$1" in men and (omen

.onounsaturates 1" of food energy1)$8" in men1)$" in (omen

+ /$!"#es $) Fat in the UK



+ /$!"#es $) Fat in the UK

%ietType of fat $ource

Total fat

.eat and meat products #)'"&

ereals and cereal products #incl$ ca/es and biscuits&#12"&.il/ and mil/ products #1"&Fat spreads #1,"&3otatoes and sa4oury snac/s #2"&5ggs and fish #2"&

Saturated fatty acids

.eat 6 meat products #)!"&

.il/ 6 mil/ product #))"&ereal products #12"&Fat spreads #1,"&Fried potatoes7sa4oury snac/s #'"&5ggs 6 egg dishes #'"&

.onounsaturated fatty

acids

.eat 6 meat products #)"&ereal products #1"&3otatoes coo/ed in oil 6 sa4oury snac/s #1)"&Fat 6 spreads #11"&

.il/ 6 mil/ products #1,"&

+ /$!"#es $) Fat in the UK %iet



+ /$!"#es $) Fat in the UK %iet

n- #omega-& fatty

acids

3otatoes coo/ed in oil and sa4oury snac/s #1"&

.eat 6 meat products #1"&ereal products #1"&egetables #e%cluding potatoes& #11"&Fish 6 fish dishes #oily fish only& #1,"&

n-* #omega-*& fatty

acids

ereal products #),"&.eat 6 meat products #18"&Fat spreads #1'"&3otatoes coo/ed in oil and sa4oury snac/s #1"&egetables #e%cluding potatoes& #2"&

Trans fatty acids

9ther foods #)2"&.eat 6 meat products #)!"&::.il/ and mil/ products #))"&::ereal products #12"&:Fat spreads #1,"&:

+



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+/ ) t l <D< th i



/$2e )ats l$e" <D<, s$2e $the"s in#"ease

it

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2016-03-03 Human Nutrition Fat AZK