Basic Nuييييييييييييييييييييييt. 6& 7.ppt

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1. Basic Nutrition
Carbohydrates
Lecture 6 & 7
Dr. Fouad A Hassan

2. 2
Introduction
High basis food
Middle east, Mexico
Asia
China
Italy
Greatest calories
Promoting health
Carbohydrate at risk

3. 3
Definition of carbohydrates
Carbohydratesareorganiccompoundscontainingcarbon,
hydrogen,andoxygen,andtheymaybesimpleOR
complexmolecules.
Theterm“carbohydrate”hasbeenusedtoclassifyall
compoundswiththegeneralformulaC
n(H
2O)
n.
TypeofCarbohydrates
MonosaccharaidessuchasGlu,Gal,Fru…
DisaccharidessuchasSuc,Lac,Mal…
OligosaccharidessuchasFOS,Stacu,Ruff…
PolysaccharidessuchasStarch,DF,Pec….

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5. 5
Carbohydrates in Human Diet
Refinedfoodshaveundergoneprocessingtoremove
certainpartsoftheoriginalfood.
Recommendations forahealthydietsuggestthatwe
eatmorenaturalunrefinedsourcesofcarbohydrates
andlimitourconsumptionofrefinedgrainsandadded
sugars.

6. 6
WholeGrains?
Mostofthecarbohydratesconsumedcomefromgrains
suchaswheat,rice,andoats.
Akernelofgrainhasthreeparts:thebran,thegerm,and
theendosperm

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Thebranistheouterlayersofthekernel.Thelayersare
highinfiberandarealsoagoodsourceofmanyvitamins
andminerals.
ThegermisthesourceofplantoilsandisrichinvitaminE.
Thelargestportionofthekerneliscalledtheendosperm.
Itishighinstarchandcontainsmostoftheproteininthe
grainandsomevitaminsandminerals.
Wholegrainproducts,suchaswholewheatbread,brown
rice,andoatmeal,containtheentirekernelofthegrain,
includingthebran,germ,andendosperm.
Whole Grains?....

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Refinedgrainproducts,suchaswhitebreadandwhite
rice,aremadebyremovingthebranandthegermto
produceamoreuniformproduct.Removingthebranand
germ,however,alsoremovesmostofthefiberandreduces
theamountsofmanyofthevitaminsandminerals.
Fortification:becausenutrientsarelostwhenthebran
andgermarediscarded,refinedgrainsareenrichedwith
certainvitaminsandminerals.Enrichmentisatypeof
fortificationthataddssome,butnotall,ofthenutrientslost
inprocessingbacktothegrainssuchasthiamine,
riboflavin,niacin,folicacid,calciumandIron.
Whole Grains?....

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Digestion of Carbohydrates
Thedigestionofstarchbeginsinthemouth,wherethe
enzymesalivaryamylasebreaksitintoshorter
polysaccharides(starch,maltose,isomaltose).
Starchdigestioncontinuesinthesmallintestine,wherethe
actionofpancreaticamylasesbreaktherestof
polysaccharidesandothersmallchainintomaltose,and
otherdisaccharides.Enzymes(maltase,sucrase,lactase)
attachedtotheliningofthesmallintestinethencomplete
thedigestionofmaltoseandalsobreakthedisaccharides
sucroseandlactoseintomonosaccharides.

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Theresultingmonosaccharides,glucose,galactose,
andfructose,arethenabsorbedintothebloodand
transportedtotheliver.
Fiberisthemostabundantindigestiblecarbohydrateinour
food.Beansareagoodsourceoffiber,butalsocontain
otherindigestiblecarbohydratescalledoligosaccharides.
Theseshortpolysaccharidescannotbecompletelydigested
byhumanenzymesand,thus,passintothelarge
intestinewheretheyarebrokendownbybacteria.

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Lactose Intolerance
Lactoseintoleranceoccurswhensomeonewithlowlevel
oflactase,theintestinalenzymethatbreaksdownlactose,
drinkmilkorotherdairyproductsthatcontainlactose,the
lactoseisnotdigestedandpassesintothelargeintestine.
Here,itdrawsinwaterandismetabolizedbybacteria
toproduceacidsandgas.
Theresultissymptomssuchasabdominaldistension,
cramping,anddiarrhea.Thosewhocannottolerateany
lactosecanchoosenondairysourcesofcalciumsuchas
legumes,leafygreenvegetables,andfishconsumedwith
bonesorsoybeanmilkassourceofproteinorchoose
Lactose-freemilkorlactasetablets.

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Functions of carbohydrates
Carbohydrates serve a number of functions in the body:
Galactoseis needed in nervous tissue and to make lactose
in breast milk.
Monosaccharides deoxyriboseand riboseare needed to
make DNAand RNA, which contain genetic information
and are needed for the synthesis of proteins.
Glucose, is an energy source: it provides about 4 calories
per gram. Certain body cells, including brain cells and red
blood cells, rely almost exclusivelyon glucose for
energy. For example, 120 g/day is required for brain.

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Simple and complex sugars
Refinedsugarsandstarchescauseaquicker,greater
riseinbloodglucosethandounrefinedsourcesof
carbohydratethatcontainfiber.Thisisbecauserefined
sugarsandstarchesaredigestedandabsorbedquickly,
causingarapidriseinbloodglucose.Fiberslowsthe
absorptionofglucose,sosourcesofunrefined
carbohydrate,suchasoatmeal,legumes,andwhole
grainbreadcauseaslower,lowerriseinbloodglucose.
Includingproteinandfatwithcarbohydratesalsoslows
glucoseabsorption.
Fructoseisslowlymetabolisedthanthatofglucose.

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Healthy and Unhealthy
Carbohydrates
Adiethighincarbohydratescanbeeithergoodorbadfor
you,dependingonthetypesofcarbohydrates.
Dietsthatarehighinunrefinedsourcesofcarbohydrate,
suchaswholegrains,fruits,andvegetables,are
consideredhealthybecausetheyareassociatedwitha
lowerincidenceofavarietyofboweldisorders,heart
disease,diabetes,andcertaincancers.
Unrefinedcarbohydratesources,suchasbrownrice,
beans,andbananas,arehighinnutrientdensitybecause
theyprovidemanynutrientspercalorie.

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Refinedproductsthatarehighinaddedsugar,suchas
donuts,cakes,andcookies,arelowinnutrientdensity
becausetheycontainfewnutrientsrelativetothecalories
theyprovide.
Dietshighinaddedsugarsandrefinedgrainsare
generallyconsideredunhealthy.Thisisbecauserefined
sourcesofcarbohydratesarelowerinnutrientdensitythan
unrefinedsources.
Sugarconsumptionhasimplicatedasacauseof
hyperactivityinchildren.
Healthy and unhealthy carbohydrates…

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Sugar and Cavities?
Dentalcariesareformedwhenbacteriathatliveinthe
mouthmetabolizesugarfromthedietandproduceacid.
Theacidcanthendissolvetheenamelandunderlying
structureoftheteeth.
Simplecarbohydrates,particularlysucrose,causecavities
becausetheyareeasilybrokendownbythesebacteria,but
starchcanalsobemetabolizedbybacteriatoproduceacids
thatcontributetotoothdecay.Preventingcavities
requiresproperdentalhygiene,evenwhenthedietislowin
sugar.

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Do Sweets and Starchy Foods
Make You Fat?
Dietshighincarbohydratesmayincreasebothhungerand
thestorageofbodyfat.
Lowcarbohydratedietscauselessinsulinreleaseandalso
causetheproductionofmoleculescalledketones.Ketones
aremadewhenfatisbrokendown,andcarbohydratelevels
arelow.Lowbloodinsulinlevelsandelevatedbloodketone
levelssuppressappetite.
Thetypeofcarbohydrateisasimportantastheamount
whenitcomestoinsulinlevelsandweightloss.

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Do Refined Carbohydrates Cause
Diabetes?
Refinedstarchesandaddedsugarsrisebloodglucose
and,subsequently,insulinlevelsinthebloodmore
sharplythanwhenunrefinedcarbohydratesareeaten.
Long-termconsumptionofadietthatishighinrefined
starchesandaddedsugarsmayincreasetheriskof
developingtype2diabetes.

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How Much and What Kind of Carbohydrates
Do You Need?
Tomeettheneedofcarbohydrates,theDRIsrecommend
theconsumptionofatleast150gramsofcarbohydrates
perday.
However,inordertomeetthebody’senergyneedswithout
providingtoomuchfatorprotein,thedietshouldcontain
morethanthis—between45%and65%ofcaloriesfrom
carbohydrates.Thisisequivalentto225to325gramsof
carbohydratesforsomeonewhoeats2,000caloriesaday.
Itisrecommended thathalfourgrainsbewhole
grains.

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Wecancutoutaddedsugarbyhavingfruitinsteadof
bakedgoodsfordessert,drinkingwaterinsteadofsoda,
andswitchingtounsweetenedbreakfastcereal.Wholegrain
consumptioncanbeincreasedbyswitchingtowhole-grain
breads,brownrice,andwhole-grainbreakfastcereals.
Sugar
Peoplewholovesweetsbutdon’tlikethecaloriesthese
foodsaddtotheirdietmighttryartificialsweeteners.
Therearefiveartificialsweetenerscommonlyusedinfoods
soldintheUnitedStates:saccharine,aspartame,
AcesulfameK,sucralose,andstevia.Theyaregenerallysafe
forhealthypeople.
How Much and What Kind of Carbohydrates Do
You Need?.....

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Dietary Fiber

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Dietaryfiberistheediblepartsofplantsoranalogous
carbohydratesthatareresistanttodigestionandabsorption
inthehumansmallintestinewithcompleteorpartial
fermentationinthelargeintestine.
Theterm“dietaryfiber”referstotheindigestiblepartsof
plants.
Definition of dietary fiber

25. 25
Types of Fiber in the Diet
Fibershavebeentraditionallycategorizedbasedontheir
solubilityinwater:
Insolubledietaryfibers(IDF)donotdissolveinwater.
Thesefibersarederivedprimarilyfromthestructuralpartsof
plants.Chemically,theyincludeligninandcelluloseand
somehemicelluloses.
Solubledietaryfibers(SDF)formviscoussolutionswhen
placedinwater.Solublefibersareoftenaddedtofoodsin
processing.Pectinisusedtothickenjamsandjellies.Gums,
suchasgumarabic,gumkaraya,guargumandgum
tragacanth

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Dietary Sources of Soluble
and Insoluble Fiber

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SDFhelpsincreasethefeelingoffullness,therebyhelping
toeatlesswithoutfeelinghungry.Ithasalsobeenshownto
helptheloweringofLDLinblood.Inaddition,itcanlower
theriskofdevelopingdiabetesbyregulatingbloodsugar
levelsandlowerglycaemicindex.Thebeneficialeffectof
SDFmaybemediatedthroughslowabsorptionand
digestionofcarbohydratesleadingtoareducedinsulin
demand.
IDFcanhelpreducetheriskofcoloncancer,and
constipationbyspeedingupthepassageoffoodthrough
theintestine.IDFshortenstheintestinaltransittime,and
thereforeallowslesstimeforcarbohydratestobeabsorbed.
Beneficial effects of dietary fiber

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Pectin as Example
of SDF

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Foradult,therecommendedintakeofdietaryfiber(DF)is
between25and35g/d(FAO,1998).Ahigh-fiberdietcan
causeconstipationandeffectonabsorptionofsomeVit.&
Menerals.
How Much Fiber Do You Need?
The RDIs for children as the
below simple equation
DF for Children (gm) = The age of child (year) + 5