Nutrition and food constituents

Nutrition: it is the dynamic processes by which the body can utilize the consumed food for energy production, growth, tissue maintenance and regulation of body functions.

1. Dr. Dalia El-Shafei
Assoc. prof., Community Medicine Department, Zagazig
University
http://www.slideshare.net/daliaelshafei

2. LEARNING OBJECTIVES:
Identify sources, functions, effect of deficiency of nutrients.
Understand the characteristics of adequate, balanced diet.
Develop a diet plan by using the dietary guides and nutritional pyramid.
Describe diets for vulnerable groups.
Understand the causes, manifestations and control of malnutrition problems.
Explain methods of assessment of nutritional status.
Describe diet plans for selected chronic diseases (therapeutic diet).

4. Nutrition
•The dynamic processes by which the body can utilize the consumed food for energy
production, growth, tissue maintenance and regulation of body functions.
A nutrient
•A chemical substance that is present in food & needed by the body in amounts of g. as
macronutrients(carbohydrates, proteins, fats) or mg. or µg. as micronutrients
(vitamins, minerals) for energy production, growth and regulation of body functions.
Food
•Anything liquid or solid formed of different nutrients & utilized by the body for
energy production, growth, tissue maintenance, and regulation of body functions.
Diet
•The whole dailyconsumed food.
A
kilocalorie
•The unit of measure used to express the fuelvalue produced from food. It equals
the amount of heat needed to raise the temperature of 1 liter of water 1°C.

5. Safe food
•Thefoodwhichisfreeofartificialornaturalharmful
compounds,notcontaminatedwithinfectiousagentsor
toxinsorheavymetalsandnotpollutedbyradiation.
Food security
•Theavailabilityoffoodinadequatequantity&quality
withreasonablepriceatanytimeforallgroupsof
population.
Food
supplementation
•Providingoffoodofahighnutritivevaluetovulnerable
groupsatlowpricesorfreeofchargee.g.,milkpowder
forinfants,flour,cheese&cerealsforpregnant&
lactatingmothers.
Food fortification
•Additionofacertainnutrienttoaparticularfoodinwhich
itisdeficienttoimproveitsnutritivevalue,e.g,addition
ofI2totablesalt,irontoflour,vitaminsA&D&Eto
vegetableoils&powderedmilk.
Food enrichment
•Additionofcertainnutrientstofoodwhichlostduring
foodbakingorprocessingasadditionofvit.Btoflour&
vit.Ctomilk.

8. FOOD CONSTITUENTS:
Macronutrients:
Nutrients which
are needed in
grams as:
carbohydrates,
proteins and fats.
Micronutrients:
which are needed
in milligrams or
micrograms as
vitamins,
minerals and
trace elements.
Water: it forms
about 70% of
body weight.

10. CARBOHYDRATES
Formed for C-H-
O atoms.
Carbon atom is
the source of
energy.
They are mainly
found in plant
foods (made by
photosynthesis).
Only animal food
containing crab.
is milk “source of
sugar (lactose)
for babies before
they be able to
eat solid food”
About 50-55% of
daily energy
requirements
“recommended
by the guidelines
for healthy diet”.

11. FUNCTIONS OF CARBOHYDRATES:
Provide
energy: 1
gram → 4
kcals.
Spare
protein from
burning for
energy
production.
Aid in more
efficient &
complete
oxidation of
fats for
energy
production.
Dietary
fibers

12. Functionsofsolublefibers(as
whiteapple,pectins,beans….etc)
•↓totalserumcholesterollevelbecause
theyabsorbbilesaltsinintestine,so
liverconsumesmoreamountof
cholesteroltoformmorebilesalts.
•Helppromotenormalbloodglucose
level(delaydigestion).
•Enhancebodyuseofinsulinininsulin
resistancesyndromeasalltypesoffibers
contributetolowglycaemicindexmeals.
Functionsofinsolublefibers(as
appleskin,cellulose….etc)
•Absorbwater10-15timestheir
volume,soaddbulktofood.
•Satiatingaction.
•Stimulateintestinalmotility,so
preventconstipation→ ↓colonic
pressure&↓absorptionoftoxinsand
carcinogensfromcolon.

13. DISORDERS OF EXCESS CARBOHYDRATE INTAKE:
(EXCESS SUGAR INTAKE)
Obesity(with
its
complications).
Dental caries
(sucrose is
cariogenic).
↑ Insulin output
•↑Blood
triglycerides→↑fat
deposition &
atherosclerosis
•↑ tendency for blood
clotting.
•More rapid return to
hunger pains after a big
meal.

14. LIPIDS
All fats are lipids but not all lipids are fats

15. FATS:
FormedofC-H-Oatomswithgreater
concentrationofcarbon→moreenergy
values“1gm→9kcals”.
Fatsinourbodies(inadiposetissue)95%
aretriglycerideswhichareformedof3fatty
acids+1moleculeglycerol(water-soluble
carbohydrate)whichallowsthetransportof
fatsthroughthewater-basedbloodstream.

17. FATTY ACIDS: ARE CLASSIFIED INTO
Saturated F.A. (SFA): hard in
room temp., mainly animal fats,
coconut oil, palm oil.
Unsaturated F.A. (USFA):
liquid in room temp., mainly
vegetable oils (olive oil, corn
oil, sunflower oil & cotton seed
oil).
Essential F.A.: cannot be
synthesized in the body as:
Linoleic, Linolenic &
arachidonic acids.
Non-essential F.A.: can be
synthesized by the body.

18. FUNCTIONS OF FATS:
•The most concentrated source of energy: 1gm →9 kcals.
•Sparing burning of protein if carbohydrate deficient.
•Sources of essential fatty acids.
•Give satiety & add flavor and palatability to food.
•Promote absorption of fat-soluble vitamins.
•Insulate & control body temperature.
•Protect body organ by cushioning.
•Provide some structural components as cell membranes, axon sheath of nerve
cells and some digestive hormones and enzymes.
•Omeg-3 fatty acids: unsaturated F.A. (EPA-DHA) found in fish oils (sardines,
salmon and mackerel) and have the following functions:
•↓arterial stiffness. -↓clotting time of blood.
•↓ risk of cancer. -↓inflammation process. -↑level of H.D.L.
•Functions of olive oil: (monounsaturated F.A.):
•Improve insulin resistance syndrome status. -Elevate HDL level.

19. FatsincoldwaterfisharemainlyOmega-3F.A.whichdonot
solidifyintheverycoldarcticwater.Imaginethatwouldhappento
thesefishiftheirbodyfatconsistedofsaturatedfat,theywould
solidifyandsink.Therefore,fishfromcoldarcticwatershavetobe
highinOmega-3F.A.tosurvive

20. TYPES OF CHOLESTEROL:
HDLcholesterolhasmoreprotein
thanLDLorVLDLwhichallows
morecholesteroltobetakenfrom
thebodycellsresultinginremoval
ofcholesterolthroughtheliver.
High density
lipoprotein
cholesterol
(HDL-C):
Good
cholesterol
Very low density
lipoprotein
cholesterol
(VLDL-C).
Low density
lipoprotein
cholesterol
(LDL-C):
Bad
cholesterol

21. FUNCTIONS OF CHOLESTEROL:
Itisafat-relatedsubstanceasitdoesnotproduceenergy,formedin
animalliveronly,sonotfoundinplantfood(vegetableoils).
Structure of
adrenal & sex
hormones.
Synthesis of
vitamin D3.
Precursor of bile
saltswhich are
essential for fat
digestion.
Essential
component in
cell membrane.

22. NORMAL BLOOD LEVEL
Cholesterol
Total < 200 mg/dl
LDL-C <130 mg/dl
HDL-C
>40 mg/dl for
males.
>50 mg/dl for
females
Triglycerides
<150 mg/dl

23. EFFECT OF EXCESS FAT INTAKE
Overweight & obesity.
↑LDL-C & triglycerides in blood →atherosclerosis & CHD.
Diabetes mellitus type II & gall bladder stones.
Repeated heating of vegetable oils (USFA) →transformation into SFA
“junk foods with repeated frying of oils”.
Margarinewhich is trans-FA (hydrogenated saturated vegetable oils) & promotes
CVD as it ↑ LDL-C & ↓ HDL-C despite it does not contain cholesterol. Butter
contains cholesterol & SFA but it ↑ both LDL-C & HDL-C.

24. PROTEINS:
Proteins are formed
of amino acids
(C.H.O.N. atoms).

25. SOURCES OF PROTEIN (TYPES OF PROTEINS):
Complete proteins:
Contain the essential amino
acids.
Animal foods as meat, fish,
milk, eggs.
Incomplete proteins:
Not contain all the essential
amino acids & contain the
other non-essential amino
acids.
Vegetable foods as cereals,
legumes, peanuts.

26. PROTEIN REQUIREMENTS/DAY:
Adult
•0.8 gm/kg BW
Infant & Child
•2-3 gm/kg BW
Pregnant
•2-3 gm/kg BW
Lactating
•3 gm/kg BW

27. Reference
protein
It is an ideal
protein
Contains all the
essential A.A. in
optimal amounts
for human's
nutrition.
Fully digestible
& utilizable by
the body.
Examples:
human milk &
hen's egg.

28. FUNCTIONS OF PROTEINS
Bodybuilding&growth(formation,maintenanceand
repairofcells).
Formationofessentialcomponents:hormones,
enzymes,immunecells,immunoglobulins&
hemoglobin.
Regulationoffluidmovementofbloodbycontrolof
osmoticpressure.
Regulationofacid-basebalance(controlmovement
ofchemicalionsin&outofthecells).
Productionofenergy:1gram→4kcals.

29. DEFICIENCY OF PROTEINS:
In children:
growth
retardation,
wasting
(Kwashiorkor).
Nutritional
oedema.
Impaired
immunity &
more
susceptibility
to infections.
General muscle
weakness &
poor wound
healing.
Apathy &
depression.

30. WATER
Functions of Water:
Aids in digestion,
absorption, circulation
& excretion processes.
Serves as a solvent for
body constituents & as
a medium for all
chemical reactions in
the body.
Carries nutrients to &
waste products from
cells as a part of the
blood.
Regulates body
temperature.
Involves with
lubrication of the
moving parts in the
body.
Water requirements: “Adults : 1ml/K.cal., Infants: 1.5 ml/K.cal”.

32. Vitamins
•Essentialcompoundsthatcan’t
bemanufacturedbythebody
insufficientamount&haveto
besuppliedbyfood.
•Classifiedinto:
Water-soluble vitamins:
VitaminsBgroup&Vitamin
C.
Fat-soluble vitamins:
VitaminsA,D,K,E.
“Absorbedfromtheintestine
withthedietaryfatthroughthe
lymphaticsystem&storedin
liver&notexcretedinurine”.
Minerals (essential elements)
•Inorganicelements
•Classifiedinto:
Majorminerals:ascalcium
phosphorus,sodium,chlorine,
potassium,magnesiumand
sulpher.
Traceelements:asiron,zinc,
iodine,selenium,manganese,
chromiumandcopper.

33. Fat-sol. Vit. & sources Functions Deficiency
Vit.A(Retinol)
-Precursor:carotene
In:Liver,Butter,eggyolk,Darkgreenleafy
vegetables,Deepyellow&orangevegetables
andfruits
-Constituent of visual
purple.
-Necessary for growth and
reproduction
-Nightblindness.
-Xerophthalmia
keratomalacia.
-Roughdryskin.
-Retardedgrowth.
Vit.D.:
-[Ergocalciferol(D
2)]-[Cholecalciferol(D
3)]
-7-dehyrocholesterol (in skin)
-formed by U.V.R in the skin
In:-Cod liver oil -egg yolk -fish with bones
(salmon)
-Promotesabsorptionof
calcium&phosphorus.
-Favorsdepositionof
calciuminbones.
-Reducesexcretionof
phosphorusinurine.
-Rickets (children).
-Osteomalacia(adults)
-Osteoporosis.
Vit. E (Tocopherol):
Whole grain cereals, Legumes, nuts, fish, Green
leafy vegetables
-Antioxidant
-Hemopoiesis (protects
RBCs from haemolysis)
-Anemia in premature
infants
-RBCs hemolysis
Vit. K (Mendione):
Dark green leafy vegetables, Egg yolk, cheese,
Green tea
-Synthesized by intestinal bacteria
-Formation of
prothrombin and other
clotting factors.
-Hemorrhage

34. Vit.B
1(Thiamin):
Wholegrains-yeast-Organmeats-
legumes
-Helpsincarbohydratemetabolism
-Promotesgoodfunctioningofnervous
systemandothersystems.
-Beri-Beri.
-Polyneuritis.
Vit.B
2(Riboflavin):
Wholegrains,yeast-Organmeats,
eggs,milk,milkproducts,greenleafy
vegetables
Helpsinmetabolismofcarbohydrates,
proteinsandfats.
-Angularstomatitis.
-Cheilosis-Cataract
-Tongueinflammation
Vit.B
3(Niacin):
Wholegraincereals-Legumes,yeast-
meat,meatorgans
-Carbohydratemetabolism -Pellagra
-Depression
Vit.B
12(Cobalamin):
Animalsourceproteinonlyas:meat,
milk,eggs.
-HbSynthesis&FormationofRBCs.
-Folicacidmetabolism
-Megaloblasticanemia
-Neuritis
Folicacid(Folacin):
Darkgreenleafyvegetables,legumes,
wholegraincereals,meats,eggs
-FormationofRBCs -Megaloblasticanemia
-Neuraltubedefect.
Vit.C(ascorbicacid):
Citrusfruits,tomatoes,strawberries,
greenleafyvegetables,greenpeppers,
broccoli
-Antioxidant-Woundhealing
-Collagentissueformation-Iron
absorption.
-Connectivetissuesofbloodvessels
-Scurvy-Anemia
-Swollen& bleeding
gums

35. Major minerals Functions Deficiency
Calcium(Ca
++
):Milk–milkproducts
-greenleafyvegetables-sardines,
salmonwithbones
-Bone and teathformation
-Aids in blood coagulation
-Helps in muscles contractions
-Aids in enzymatic functioning
-Rickets-Osteomalacia
-Osteoporosis-Poorblood
Clotting
Phosphorus(P
3-
):Milk–milk
products–eggyolk–meat–nuts–
legumes–wholegrains
-Bone and teeth formation
-Energy metabolism
-Aids in acid-base balance
-Fragilebones-Stiffjoints
Potassium(K
+
):Banana,orange,
apricots,carrots,potatoes–meats,
milk,milkproducts-legumes,
molasses,tea
-Musclescontractions
-Keyroleinacid-basebalance
-Aidsinenzymaticreactions
-↓heartrate -bone
fragility
Sodium (Na
+
):(Insodium
chloride)Commonsalt,naturallyin
vegetablesandmilk
-Maintenanceofacid-basebalance
-Controlofmusclecontractions
-disturbedmuscleaction
(musclecramps)
Magnesium(Mg
++
):Darkgreenleafy
vegetables-wholegrains,nuts-bran-
banana–apricots-seafoods-tea–
coffee
-Boneandteethformation
-Proteinsynthesis&lipidmetabolism
-Regulatesheartbeats
-C.N.S.problem,as:confusion,
apathy,hallucinations-
Arrhythmia
-Cramps -Tremors

36. Minerals “Trace elements” Functions Deficiency
Iron(Fe
+++
):
Haemesources:liver,redmeat
Nonhaemesource:Darkgreenleafy
vegetables,legumes,wholegrains,
molasses,driedfruits
-Essentialforformationof
haemoglobin(inRBCs)
-Partofenzymesandproteins.
-Irondeficiency
anemia
Selenium(Se):Meat,eggs,liver,
wholegraincereals,seafoods,garlic
-Antioxidant-↓cancerrisk
-PlaysaroleinpreventionofHIV
replication
-Playsakeyroleinimmunesystem
Iodine(I
-
):Fishinsalt,water,
vegetablesgrowniniodine-richsoil
-Regulatesenergymetabolismasa
partofthyroidhormone
-Endemicgoiter
-Cretinism.
Zinc(Zn
++
):Wholegrains,wheat
germ,liver,yeast,seafoods,milk
-Growth&reproduction
-Immunity,neurologicalfunctions
&smellacuity.
-Retardedgrowth&
sexualmaturation
Copper(Cu
++
):Shellfish,liver,nuts,
whilegrains,chocolates
-Information&survivalofRBCs
-Inlipidmetabolism
-Anemia
-CNSproblems
Chromium(Cr
+++
):Liver,whole
grainscheese,legumes,yeast
-Activateenzymaticaction
-Enhancesremovalofglucosefrom
blood
-CNSproblems
-DMaggravation

37. PHYTOCHEMICALS

38. Theseare1000ormorenewlyrecognizednon-nutritive
plantchemicalsneithervitaminsnormineralsandhave
diseasepreventiveeffects.

39. FUNCTIONS OF PHYTOCHEMICALS
•Flavonoids(apples & green tea): ↓cancer lung risk.
Lycopene(tomatoes & pepper): ↓cancer prostate risk
“antioxidant effect 2 times as powerful as vit.A”.
Antioxidant & Anti-
cancer:
•Reduce menopausal symptoms, osteoporosis and cancer
risk.
Hormonal &
Enzymatic
stimulation effect
•Grapes, nuts, rosemary, tea, whole grains, legumes and
soybeans.
Anti-inflammatory &
Anti-blood clotting
effect
•Green tea. ↓ LDL-C & ↑ HDL-C