浙江工商大学食品营养学教案(教学第一章)课件

Chapter1

FoodChoicesandHumanHealthChapter1

FoodChoicesandHuma1Food:medically,anysubstancethatthebodycantakeinandassimilatethatwillenableittostayaliveandtogrow;thecarrierofnourishment;socially,amorelimitednumberofsuchsubstancesdefinedasacceptablebyeachculture.Nutritionthestudyofthenutrientsinfoodsandinthebody;sometimesalsothestudyofhumanbehaviorsrelatedtofood.Dietthefoods(includingbeverages)apersonusuallyeatsanddrinks.Food:medically,anysubstance2Nutrientscomponentsoffoodthatareindispensabletothebody'sfunctioning.Theyprovideenergy,serveasbuildingmaterial,helpmaintainorrepairbodyparts,andsupportgrowth.Thenutrientsincludewater,carbohydrate,fat,protein,vitamins,andminerals.Malnutritionanyconditioncausedbyexcessordeficientfoodenergyornutrientintakeorbyanimbalanceofnutrients.Nutrientorenergydeficienciesareclassedasformsofundernutrition;nutrientorenergyexcessesareclassedasformsofovernutrition.Nutrientscomponentsoffoodt3ALifetimeofNourishmentYourbodyrenewsitsstructurescontinuously,andeachdayitbuildsalittlemuscle,bone,skin,andblood,replacingoldtissueswithnew.Itmayalsoaddalittlefat,ifyouconsumeexcessfoodenergy(calories),orsubtractalittle,shouldyouconsumelessthanyourequire.Inthiswaysomeofthefoodyoueattodaybecomespartof"you"tomorrow.ALifetimeofNourishmentYour4ALifetimeofNourishmentThebestfoodforyou,then,isthekindthatsupportsthegrowthandmaintenanceofstrongmuscles,soundbones,healthyskin,andsufficientbloodtocleanseandnourishallpartsofyourbody.Thismeansyouneedfoodthatprovidesnotonlyenergybutalsosufficient'nutrients,'thatis,enoughwater,carbohydrates,fat,protein,vitamins,andminerals.Ifthefoodsyoueatprovidetoolittleortoomuchofanynutrienttoday,yourhealthmaysufferjustalittle.It'thefoodsyoueatprovidetoolittleortoomuchofoneormorenutrientseverydayforyears,then,bythetimeyouareold,youmaywellsufferseverediseaseeffects.ALifetimeofNourishmentThe5ALifetimeofNourishment

Thenutrientsinfoodsupportgrowth,maintenance,andrepairofthebody.Deficiencies,excesses,andimbalancesofnutrientsbringonthediseasesofmalnutrition.ALifetimeofNourishmentT6HowPowerfulIsaNutritiousDietinPreventingDiseases?Yourchoiceofdietprofoundlyinfluencesyourlong-termhealthprospects.Onlytwocommonlifestylehabitsaremoreinfluential:smokingandothertobaccouse,andexcessivedrinkingofalcohol.Manyolderpeoplesufferfromdebilitatingconditionsthatcouldhavebeenlargelypreventedhadtheyknownthenutritionprinciplesthatweknowtodayandappliedthoseprinciplesthroughouttheirlives.HowPowerfulIsaNutritiousD7malnutritionjustdescribed,butalsootherdiseases,especiallythechronicdiseasesheartdisease,diabetes,somekindsofcancer,dentaldisease,adultboneloss,andothers.Weshouldhastentosaythatalthoughdietcanpowerfullyinfluencethesediseases,theycannotbepreventedbyagooddietalone;theyaretosomeextentdeterminedbyaperson'sgeneticconstitution,activities,andlifestyle?Withintherangesetbyyourinheritance,however,thelikelihoodthatyouwilldevelopthesediseasesisstronglyinfluencedbyyourfoodchoices.malnutritionjustdescribed,b8Nutritionprofoundlyaffectshealth.

GeneticsandIndividualityChoiceofdietinfluenceslong-termhealth,withintherangesetbygeneticinheritance.Nutritionhasnoinfluenceonsomediseasesbutiscloselylinkedtoothers.Nutritionprofoundlyaffectsh9浙江工商大学食品营养学教案(第一章)课件10Chronicdiseases.chronicdiseaseslong-durationdegenerativediseasescharacterizedbydeteriorationofthebodyorgans;examplesincludeheartdisease,cancer,anddiabetes.Anemiaisabloodconditioninwhirlredbloodcellsareinadequateorimpaired,andsocannotmeettheoxygendemandsofthebody.Moreabouttheanemiaofsickle-celldiseaseinChapter6;iron-deficiencyanemiaisdescribedinChapter8Chronicdiseases.chronicdise11WithhigherconcentrationofHbS(eg.SCD)andlowoxygenlevels,HbSformspolymersinsideredbloodcells.HbSpolymerscauseredbloodcellstoform“sickle”shapes.Sickleshapedredbloodcellshavedecreasedabilitytotravelthroughbloodvesselswhich,inturn,mayclogbloodvesselsinorgansandleadtolossoftissuefunction.SickleCellNormalCellWithhigherconcentrationofH12WhyBothertoBeActive?Person’sdailyfoodchoicecanpowerfullyinfluencethelong-termhealth,butthecombinationofnutritionwithphysicalactivityismorepowerfulstill.Peoplewhoareactivemayreceivethesebenefits:WhyBothertoBeActive?13Reducedriskofcardiovasculardiseases.Reducedriskofsometypesofcancer(especiallyofthecolonorbreast).Improvedmentaloutlookandlessenedlikelihoodofdepression.Improvedmentalfunctioning.Feelingofvigor.Feelingofbelonging--thefunandcompanionshipofsports.Reducedriskofcardiovascular14

Strongself-imageandself-confidence.Reducedbodyfatnessandincreasedleantissue.Greaterbonedensityand,thus,lessenedriskorreducedseverityofbonediseaselaterinlife.Sound,beneficialsleep.Amoreyouthfulappearance,healthyskin,andimprovedmuscletone.

Strongself-imageandself-co15

Fasterwoundhealing.Improvementoreliminationofmenstrualcramping.Improvedresistancetocoldsandinfection.Fasterwoundhealing.16LifestyleChoicesOtherlifestylechoicesbesidepeople’schoiceofwhatfoodstoeat,alsoaffecttheirhealth.Tobaccoandalcoholuseandothersubstanceabusecanallbedestructiveofhealth.Personallifechoices,suchasuseoftobaccooralcoholorstayingphysicallyactive,alsoaffecthealthforthebetterorworse.LifestyleChoicesOtherlifest17浙江工商大学食品营养学教案(第一章)课件18

TheHumanBodyandItsFoodAsyourbodyliveseachday,itmovesandworks,andtomovesorworks,itmustuseenergy.Theenergythatfuelsthebody’sworkcomesindirectlyformthesunbywayofplants.sunplantanimalyouSolarenergyfruitsgrainsvegetables

TheHumanBodyandItsFoodA19TheNutrientsinFoodsTheNutrientsinFoods20Figure1-2MaterialsofFoodandtheHumanBody

Foodsandthehumanbodyaremadeofthesamematerials.

Figure1-2MaterialsofFoo21Foodsuppliesenergyandnutrients.Themostvitalnutrientiswater.Theenergyyieldingnutrientsarecarbohydrates,fats(lipids),andprotein.Thehelpernutrientsarevitaminsandminerals.Foodenergyismeasuredincalories;foodandnutrientquantitiesareoftenmeasuredingrams.CalorievaluesofenergynutrientsCarbohydrate4cal/g17kJ/gFat(lipid)9cal/g38kJ/gProtein4cal/g17kJ/gFoodsuppliesenergyandnutri22caloriesunitsofenergy.Strictlyspeaking,theunitusedtomeasuretheenergyinfoodsisakilocalorie(kcalorie,orCalorie):itistheamountofheatenergynecessarytoraisethetemperatureofakilogram(aliter)ofwater1degreeCelsius.caloriesunitsofenergy.Stri23Energy-yieldingnutrients:Thenutrientsthebodycanuseforenergy.Theymayalsosupplybuildingblocksforbodystructures.CarbohydrateFatProteinEssentialnutrients:Thenutrientsthebodycannotmakeforitself(orcannotmakefastenough)fromotherrawmaterial;nutrientsthatmustbeobtainedfromfoodtopreventdeficiencies.浙江工商大学食品营养学教案(第一章)课件24CanIForgoFoodandLiveJustonsupplements?

supplementspills,liquids,orpowdersthatcontainpurifiednutrientsorotheringredients(seeChapter7).elementaldietsdiets

composedofpurifiedingredientsofknownchemicalcomposition;intendedtosupplyallessentialnutrientstopeoplewhocannoteatfoods.CanIForgoFoodandLiveJust25WhatAretheNonnutrientsandPhytochemicalsThatIHearaboutintheNews?Foodscontaincompoundsotherthannutrients,thephytochemicals,thatgivethemtheirtastes,aromas,colors,andothercharacteristics.Somephytochemicalsarebelievedtoplayrolesindiseaseprevention.WhatAretheNonnutrientsand26Thescienceofnutrition

IftheScientistsDon'tKnow,HowCanI!Everyonestampedesforoatbran,redwine,orfishoilbasedontoday'snewsthattheseproductsaregoodforhealth.Thentomorrow'snewsreports,"Itisn'ttrueafterall,"andeveryonedropsoatbran,redwine,orfishoilandtakesupthenextcraze.Meanwhile,bewilderedconsumerscomplaininfrustration,"Thosescientistsdon'tknowanything."Thescienceofnutrition

Ift27Intruth,though,itisascientistsbusinessnottoknow.Scientistsobtainfactsbysystematicallyaskingquestions--that'stheirjob.Thentheyconductexperimentsdesignedtotestforvariouspossibleanswers(seeFigure1-3andTable1-4onthenextpage).Intruth,though,itisascie28Whentheyhaveruledoutsomepossibilitiesandfoundevidenceforothers,theysubmittheirfindings,nottothenewsmedia,buttoboardsofreviewerscomposedofotherscientistswhotrytopickthefindingsapart.Ifthereviewersconsidertheconclusionstobewellsupportedbytheevidence,theyendorsetheworkforpublication,notinthenewsmedia,butinscientificjournalswherestillotherscientistscanreadit.Whentheyhaveruledoutsome29Figure1-3ResearchDesignFigure1-3ResearchDesign30浙江工商大学食品营养学教案(第一章)课件31ScientificChallenge

Onceanewfindingispublished,itisstillonlypreliminary.Oneexperimentdoesnot"prove"or"disprove"anything.Thenextstepisforotherscientiststoattempttoduplicateandsupporttheworkofthefirstresearchersortochallengethefindingbydesigningexperimentstorefuteit.ScientificChallengeOnceane32

CanITrusttheMediatoDeliverNutritionNews?Thenewsmediaarehungryfornewfindings,andreportersoftenlatchontoideasfromthescientificlaboratoriesbeforetheyhavebeenfullytested.Orareporterwholacksastrongunderstandingofsciencemaymisunderstandcomplexscientificprinciples)Totellthetruth,sometimesscientistsgetexcitedabouttheirfindings,too,andleakthemtothepressbeforetheyhavebeenthrougharigorousreviewbythescientists'peers.Asaresult,thepublicisoftenexposedtolate-breakingnutritionnewsstoriesbeforethefindingsarefullyconfirmed.Then,whenthehypothesisbeingtestedfailstoholduptoalaterchallenge,consumersfeelbetrayedbywhatissimplythenormalcourseofscienceatwork.TheConsumerCornerofferssometipsforevaluatingnewsstoriesaboutnutrition.CanITrusttheMediatoDeli33Scientistsuncovernutritionfactsbyexperimenting.Singlestudiesmustbereplicatedbeforetheirfindingscanbeconsideredvalid.Newnutritionnewsisnotalwaystobebelieved;establishednutritionnewshasstooduptothetestoftime.Scientistsuncovernutrition34ThechallengeofChoosingFood

Thevarietyoffoodstochoosefrom

ThechallengeofChoosingFoo35Table1-4Glossaryoffoodtypesbasicfoodsmilkandmilkproducts;meatsandsimilarfoodssuchasfishandpoultry;vegetables,includingdriedbeansandpeas:fruits;andgrains.Thesefoodsaregenerallyconsideredtoformthebasisofanutritiousdiet.Alsocalledwholefoods.enrichedfoodsandfortifiedfoodsfoodstowhichnutrientshavebeenadded.Ifthestartingmaterialisawhole,basicfoodsuchasmilkorwholegrain,theresultmaybehighlynutritious.Ifthestartingmaterialisaconcentratedformofsugarorfat,theresultmaybelessnutritious.Table1-436functionalfoodsatermthatreflectsanattempttodefineasagroupthefoodsknowntopossessnutrientsornonnutrientsthatmightlendprotectionagainstdiseases.However,allnutritiousfoodscansupporthealthinsomeways..naturalfoodsatermthathasnolegaldefinition.nutraceuticalatermwithnolegalorscientificmeaning,butsometimesusedtorefertofoods,nutrients,ordietarysupplementsbelievedtohavemedicinaleffects(seeChapter11).Oftenusedtosellunnecessaryorunprovedsupplements.functionalfoodsatermthatr37fastfoodsrestaurantfoodsthatareavailablewithinminutesaftercustomersorderthem--traditionally,hamburgers,frenchfries,andmilkshakes;morerecently,saladsandothervegetabledishesaswell.Thesefoodsmayormaynotmeetpeople'snutrientneedswell,dependingontheselectionsmadeandontheenergyallowancesandnutrientneedsoftheeaters.fastfoodsrestaurantfoodsth38organicfoodsunderstoodtomeanfoodsgrownwithoutsyntheticpesticidesorfertilizers.Inchemistry,however,allfoodsaremademostlyoforganic(carbon-containing)compounds.(SeeChapter14'sConsumerCornerfordetails.)

partitionedfoodsfoodscomposedofpartsofwholefoods,suchasbutter(frommilk),sugar(frombeetsorcane),orcornoil(fromcorn).Panicfoodsunderstoodtome39processedfoodsfoodssubjectedtoanyprocess,suchasmilling,alterationoftexture,additionofadditives,cooking,orothers.Dependingonthestartingmaterialandtheprocess,aprocessedfoodmayormaynotbenutritious.staplefoodsfoodsusedfrequentlyordaily,forexample,rice(intheFarEast)orpotatoes(inIreland).Ifwellchosen,thesefoodsarenutritious;certainly,cessedfoodsfoodssubjecte40Anutritiousdietfollowsthea,b,c,m,vprinciples:~adequacy~balance~caloriecontrol~moderation~varietyWhatExactlyIsaNutritiousDiet?AnutritiousdietfollowstheW41Anutritiousdiethasfivecharacteristics.Oneisadequacy:thefoodsprovideenoughofeachessentialnutrient,fiber,andenergy.Anotherisbalance:thechoicesdonotoveremphasizeonenutrientorfoodtypeattheexpenseofanother.Thethirdiscaloriecontrol:thefoodsprovidetheamountofenergyyouneedtomaintainappropriateweight--notmore,notless.Thefourthismoderation:thefoodsdonotprovideexcessfat,salt,sugar,orotherunwantedconstituents.Thefifthisvariety:thefoodschosendifferfromonedaytothenext.Anutritiousdiethasfivecha42adequacythedietarycharacteristicofprovidingalloftheessentialnutrients,fiber,andenergyinamountssufficienttomaintainhealthandbodyweight.balancethedietarycharacteristicofprovidingfoodsofanumberoftypesinproportiontoeachother,suchthatfoodsrichinsomenutrientsdonotcrowdoutofthedietfoodsthatarerichinothernutrients.Alsocalledproportionality.caloriecontrolcontrolofenergyintake;afeatureofasounddietplan.moderationthedietarycharacteristicofprovidingconstituentswithinsetlimits,nottoexcess.varietythedietarycharacteristicofprovidingawideselectionoffoodstheoppositeofmonotony

adequacythedietarycharacter43KEYPOINTAwell-planneddietisadequateinnutrients,isbalancedwithregardtofoodtypes,offersfoodenergythatmatchesenergyexpendedinactivity,ismoderateinunwantedconstituents,andoffersvariety.Foodsofhighnutrientdensityformthefoundationofsuchadiet.KEYPOINTAwell-planneddiet44nutrientdensity

ameasureofnutrientsprovidedpercalorieoffood.nutrientdensity45浙江工商大学食品营养学教案(第一章)课件46SelfCheckquestions1.Studiesofwholepopulationsthatrevealcorrelationsbetweendietaryhabitsanddiseaseincidencearereferredtoas:erventionstudiesc.laboratorystudiesd.epidemiologicalstudies2.Energy-yieldingnutrientsincludeallofthefollowingexcept:tein3.Organicnutrientsincludeallofthefollowingexcept:tein

SelfCheckquestions1.Studi474.Oneofthecharacteristicsofanutritiousdietisthatitprovidesnoconstituentinexcess.Thisprincipleofdietplanningiscalled:a.adequacyb.balancec.moderationd.variety5.Asliceofpeachpiesupplies357calorieswith48unitsofvitaminA;onelargepeachprovides42caloriesand53unitsofvitaminA.Thisisanexampleof:a.caloriecontrolb.nutrientdensityc.Varietyd.essentialnutrients6.Heartdiseaseandcancerareduetogeneticcauses,anddietcannotinfluencewhethertheyoccur.TF4.Oneofthecharacteristics48Controversy1IDENTIFYINGVALIDNUTRITIONINFORMATIONControversy149Chapter1

FoodChoicesandHumanHealthChapter1

FoodChoicesandHuma50Food:medically,anysubstancethatthebodycantakeinandassimilatethatwillenableittostayaliveandtogrow;thecarrierofnourishment;socially,amorelimitednumberofsuchsubstancesdefinedasacceptablebyeachculture.Nutritionthestudyofthenutrientsinfoodsandinthebody;sometimesalsothestudyofhumanbehaviorsrelatedtofood.Dietthefoods(includingbeverages)apersonusuallyeatsanddrinks.Food:medically,anysubstance51Nutrientscomponentsoffoodthatareindispensabletothebody'sfunctioning.Theyprovideenergy,serveasbuildingmaterial,helpmaintainorrepairbodyparts,andsupportgrowth.Thenutrientsincludewater,carbohydrate,fat,protein,vitamins,andminerals.Malnutritionanyconditioncausedbyexcessordeficientfoodenergyornutrientintakeorbyanimbalanceofnutrients.Nutrientorenergydeficienciesareclassedasformsofundernutrition;nutrientorenergyexcessesareclassedasformsofovernutrition.Nutrientscomponentsoffoodt52ALifetimeofNourishmentYourbodyrenewsitsstructurescontinuously,andeachdayitbuildsalittlemuscle,bone,skin,andblood,replacingoldtissueswithnew.Itmayalsoaddalittlefat,ifyouconsumeexcessfoodenergy(calories),orsubtractalittle,shouldyouconsumelessthanyourequire.Inthiswaysomeofthefoodyoueattodaybecomespartof"you"tomorrow.ALifetimeofNourishmentYour53ALifetimeofNourishmentThebestfoodforyou,then,isthekindthatsupportsthegrowthandmaintenanceofstrongmuscles,soundbones,healthyskin,andsufficientbloodtocleanseandnourishallpartsofyourbody.Thismeansyouneedfoodthatprovidesnotonlyenergybutalsosufficient'nutrients,'thatis,enoughwater,carbohydrates,fat,protein,vitamins,andminerals.Ifthefoodsyoueatprovidetoolittleortoomuchofanynutrienttoday,yourhealthmaysufferjustalittle.It'thefoodsyoueatprovidetoolittleortoomuchofoneormorenutrientseverydayforyears,then,bythetimeyouareold,youmaywellsufferseverediseaseeffects.ALifetimeofNourishmentThe54ALifetimeofNourishment

Thenutrientsinfoodsupportgrowth,maintenance,andrepairofthebody.Deficiencies,excesses,andimbalancesofnutrientsbringonthediseasesofmalnutrition.ALifetimeofNourishmentT55HowPowerfulIsaNutritiousDietinPreventingDiseases?Yourchoiceofdietprofoundlyinfluencesyourlong-termhealthprospects.Onlytwocommonlifestylehabitsaremoreinfluential:smokingandothertobaccouse,andexcessivedrinkingofalcohol.Manyolderpeoplesufferfromdebilitatingconditionsthatcouldhavebeenlargelypreventedhadtheyknownthenutritionprinciplesthatweknowtodayandappliedthoseprinciplesthroughouttheirlives.HowPowerfulIsaNutritiousD56malnutritionjustdescribed,butalsootherdiseases,especiallythechronicdiseasesheartdisease,diabetes,somekindsofcancer,dentaldisease,adultboneloss,andothers.Weshouldhastentosaythatalthoughdietcanpowerfullyinfluencethesediseases,theycannotbepreventedbyagooddietalone;theyaretosomeextentdeterminedbyaperson'sgeneticconstitution,activities,andlifestyle?Withintherangesetbyyourinheritance,however,thelikelihoodthatyouwilldevelopthesediseasesisstronglyinfluencedbyyourfoodchoices.malnutritionjustdescribed,b57Nutritionprofoundlyaffectshealth.

GeneticsandIndividualityChoiceofdietinfluenceslong-termhealth,withintherangesetbygeneticinheritance.Nutritionhasnoinfluenceonsomediseasesbutiscloselylinkedtoothers.Nutritionprofoundlyaffectsh58浙江工商大学食品营养学教案(第一章)课件59Chronicdiseases.chronicdiseaseslong-durationdegenerativediseasescharacterizedbydeteriorationofthebodyorgans;examplesincludeheartdisease,cancer,anddiabetes.Anemiaisabloodconditioninwhirlredbloodcellsareinadequateorimpaired,andsocannotmeettheoxygendemandsofthebody.Moreabouttheanemiaofsickle-celldiseaseinChapter6;iron-deficiencyanemiaisdescribedinChapter8Chronicdiseases.chronicdise60WithhigherconcentrationofHbS(eg.SCD)andlowoxygenlevels,HbSformspolymersinsideredbloodcells.HbSpolymerscauseredbloodcellstoform“sickle”shapes.Sickleshapedredbloodcellshavedecreasedabilitytotravelthroughbloodvesselswhich,inturn,mayclogbloodvesselsinorgansandleadtolossoftissuefunction.SickleCellNormalCellWithhigherconcentrationofH61WhyBothertoBeActive?Person’sdailyfoodchoicecanpowerfullyinfluencethelong-termhealth,butthecombinationofnutritionwithphysicalactivityismorepowerfulstill.Peoplewhoareactivemayreceivethesebenefits:WhyBothertoBeActive?62Reducedriskofcardiovasculardiseases.Reducedriskofsometypesofcancer(especiallyofthecolonorbreast).Improvedmentaloutlookandlessenedlikelihoodofdepression.Improvedmentalfunctioning.Feelingofvigor.Feelingofbelonging--thefunandcompanionshipofsports.Reducedriskofcardiovascular63

Strongself-imageandself-confidence.Reducedbodyfatnessandincreasedleantissue.Greaterbonedensityand,thus,lessenedriskorreducedseverityofbonediseaselaterinlife.Sound,beneficialsleep.Amoreyouthfulappearance,healthyskin,andimprovedmuscletone.

Strongself-imageandself-co64

Fasterwoundhealing.Improvementoreliminationofmenstrualcramping.Improvedresistancetocoldsandinfection.Fasterwoundhealing.65LifestyleChoicesOtherlifestylechoicesbesidepeople’schoiceofwhatfoodstoeat,alsoaffecttheirhealth.Tobaccoandalcoholuseandothersubstanceabusecanallbedestructiveofhealth.Personallifechoices,suchasuseoftobaccooralcoholorstayingphysicallyactive,alsoaffecthealthforthebetterorworse.LifestyleChoicesOtherlifest66浙江工商大学食品营养学教案(第一章)课件67

TheHumanBodyandItsFoodAsyourbodyliveseachday,itmovesandworks,andtomovesorworks,itmustuseenergy.Theenergythatfuelsthebody’sworkcomesindirectlyformthesunbywayofplants.sunplantanimalyouSolarenergyfruitsgrainsvegetables

TheHumanBodyandItsFoodA68TheNutrientsinFoodsTheNutrientsinFoods69Figure1-2MaterialsofFoodandtheHumanBody

Foodsandthehumanbodyaremadeofthesamematerials.

Figure1-2MaterialsofFoo70Foodsuppliesenergyandnutrients.Themostvitalnutrientiswater.Theenergyyieldingnutrientsarecarbohydrates,fats(lipids),andprotein.Thehelpernutrientsarevitaminsandminerals.Foodenergyismeasuredincalories;foodandnutrientquantitiesareoftenmeasuredingrams.CalorievaluesofenergynutrientsCarbohydrate4cal/g17kJ/gFat(lipid)9cal/g38kJ/gProtein4cal/g17kJ/gFoodsuppliesenergyandnutri71caloriesunitsofenergy.Strictlyspeaking,theunitusedtomeasuretheenergyinfoodsisakilocalorie(kcalorie,orCalorie):itistheamountofheatenergynecessarytoraisethetemperatureofakilogram(aliter)ofwater1degreeCelsius.caloriesunitsofenergy.Stri72Energy-yieldingnutrients:Thenutrientsthebodycanuseforenergy.Theymayalsosupplybuildingblocksforbodystructures.CarbohydrateFatProteinEssentialnutrients:Thenutrientsthebodycannotmakeforitself(orcannotmakefastenough)fromotherrawmaterial;nutrientsthatmustbeobtainedfromfoodtopreventdeficiencies.浙江工商大学食品营养学教案(第一章)课件73CanIForgoFoodandLiveJustonsupplements?

supplementspills,liquids,orpowdersthatcontainpurifiednutrientsorotheringredients(seeChapter7).elementaldietsdiets

composedofpurifiedingredientsofknownchemicalcomposition;intendedtosupplyallessentialnutrientstopeoplewhocannoteatfoods.CanIForgoFoodandLiveJust74WhatAretheNonnutrientsandPhytochemicalsThatIHearaboutintheNews?Foodscontaincompoundsotherthannutrients,thephytochemicals,thatgivethemtheirtastes,aromas,colors,andothercharacteristics.Somephytochemicalsarebelievedtoplayrolesindiseaseprevention.WhatAretheNonnutrientsand75Thescienceofnutrition

IftheScientistsDon'tKnow,HowCanI!Everyonestampedesforoatbran,redwine,orfishoilbasedontoday'snewsthattheseproductsaregoodforhealth.Thentomorrow'snewsreports,"Itisn'ttrueafterall,"andeveryonedropsoatbran,redwine,orfishoilandtakesupthenextcraze.Meanwhile,bewilderedconsumerscomplaininfrustration,"Thosescientistsdon'tknowanything."Thescienceofnutrition

Ift76Intruth,though,itisascientistsbusinessnottoknow.Scientistsobtainfactsbysystematicallyaskingquestions--that'stheirjob.Thentheyconductexperimentsdesignedtotestforvariouspossibleanswers(seeFigure1-3andTable1-4onthenextpage).Intruth,though,itisascie77Whentheyhaveruledoutsomepossibilitiesandfoundevidenceforothers,theysubmittheirfindings,nottothenewsmedia,buttoboardsofreviewerscomposedofotherscientistswhotrytopickthefindingsapart.Ifthereviewersconsidertheconclusionstobewellsupportedbytheevidence,theyendorsetheworkforpublication,notinthenewsmedia,butinscientificjournalswherestillotherscientistscanreadit.Whentheyhaveruled