Malcolm教授课件 MAFIC-10 2014 Energy exp

1ENERGYEXPENDITURE1WHATISIT?HOWDOWEMEASUREIT?2DEFINITIONSBEEBASALENERGYEXPENDITURETEETOTALENERGYEXPENDITUREBMRBASALMETABOLICRATERMRRESTINGMETABOLICRATETEFTHERMICEFFECTOFFOODSPECIFICDYNAMICACTIONPOSTPRANDIALTHERMOGENESISDIETINDUCEDTHERMOGENESISEEEXERCISEENERGYEEENERGYOFEXERCISEEEPAENERGYEXPENDEDDUETOPHYSICALACTIVITYNEATNON-EXERCISEACTIVITYTHERMOGENESISSPONETANEOUSACTIVITYTHERMOGENESISRQRESPIRATORYQUOTIENTRERRESPIRATORYEXCHANGERATIOFQFOODQUOTIENT3ENERGYEXPENDITUREISHEATPRODUCTION(THERMOGENESIS)ORsinceATPsynthesisiscoupledtooxygenconsumptionENERGYEXPENDITUREISOXYGENCONSUMPTION4MethodstoEstimateTEEandEEPA•Directorindirectcalorimetry•Activitymonitors•DoublyLabeledWater5Methodstomeasureenergyexpenditureinhumans:.DirectCalorimetryMeasureheatlossesfromthebody-problem-heatstoredinbody,slowresponsetime-Usedirectcalorimeter6ANTOINELAVOSIER(METROPOLITANMUSEUMOfART,NY)THEFATHEROFMODERNCHEMISTRYANDNUTRITIONNousn’avonsplusbesoindesSavantsnidesChimistes!”7LAVOISIER&LAPLACE–DIRECTCALORIMETRY(1776/77)“Lavieestdoncunecombustion”8DirectCalorimetry•measureofheatproduction•“direct”measureofenergyexpenditure•requiresaclosedcircuit,i.e.room•subjectsmustliveincalorimeteratleast23hours/day910CHOCO2FATH20PROTEINUREAOXYGENHEAT11IndirectCalorimetry•canassessindividualcomponentsofenergyexpenditure:»energyexpenditureatrest»duringactivities»aftermeals•candeterminewhatfuelsarebeingoxidized-bydeterminingRQ(respiratoryquotient)(urea=protein)-CO2produced/O2used12OxidationofFuelsC6H12O6+6O26CO2+673kcalRQ=CO2pdced/O2used=6/6=15.01kcal/LO22(C55H106O6)+157O2110CO2+106H20+16,357RQ=110/157=0.7014.65kcal/LO213IndirectCalorimetryMethod•Heatreleasebychemicalprocessesinthebodycanbeindirectlycalculatedfromtherateofoxygenconsumption.-oxidativephosphorylationcoupledtoATPsynthesis-rateofATPutilization=overallsubstrateoxidation(andthereforeO2consumption)–butbewareofRQ14Methodsforindirectcalorimetry-Mouthpiece,DouglasBag-Hoodsystem(restingsubject)-Wholeroom15LAVOISIER–INDIRECTCALORIMETRYFig.?3AdairCrawfordbuiltthefirstrespirationcalorimeterchamberforsimultaneousmeasurementofgasexchangeandheatproduction(1788)ce:cross-refsrefid=bib10bib19[10,19]/ce:cross-refs.LikeLavoisier,Crawfordconstructedathr...DavidC.FrankenfieldNutritionVolume26,Issue102010939-9501718IndirectCalorimetry19202122RUTGERSEQUINECENTERINDIRECTCALORIMETRYWHILEONTHETREADMILL23CALORIMETRYDISRUPTIONOFEVERYDAYLIFE(beingobserved)MOUTHPIECEorinaSMALLROOMorHOODDOUGLASBAGRESTRICTEDMOVEMENT?24Pedometers/Acceleromters•UsepredictionequationtoestimateTEEbasedongender,weight,andsometimesage.•Usemovement,coupledwithBMRprediction,toestimateTEE.•Cheapandgoodforlargestudies.•Generallynotreliable(±10-20%).25CALORIMETRYDISRUPTIONOFEVERYDAYLIFE(beingobserved)MOUTHPIECEorinaSMALLROOMorHOODDOUGLASBAGRESTRICTEDMOVEMENT?ACTIVITYMONITORSaccurarcy–movementrestrictions–beingobserved26DoublyLabeledWater•Usestableisotopes,extraneutrons)•Hydrogen-1Deuterium-HD2O•Oxygen-16OH2O18•Safe,non-toxic,useinchildrentoelderly,portable(generally)•ValidforTEEandbreastfeedingestimates•Expensive,forwaterandanalyses18227DoublyLabeledWaterBODYWATERPOOL2829DoublyLabeledWater30Lossofisotope(%ofinitial)18OD-MeasuretheratioofDto18Ointheurine(massspectroscopy)-thedifferenceintherateoflossoftheisotopesisequaltotherateofCO2productionDAYS073312H18OCO2productionDifferencebetweenlossofDeuteriumandOxygen-18islarge322H18OCO2productionDifferencebetweenlossofDeuteriumandOxygen-18issmall.33EstimatingTEEwithStableIsotopesHumanbodyis____%water?Therefore,wecancalculatehowmuchleantissueabodyhasifweknowtheamountofwater.34BodyCompositionwithDLWTotalBodyWaterCalculationsTBW(moles)=((ddose-dtap)/(dpost-dpre))x(WA/18.02a)whereW=Amountofwater(grams)usedtodilutethedose,A=Amountofdose(grams)administeredtosubject,a=amountofdose(grams)dilutedforanalysis.TBW(kg)=TBW(moles)x18.02/1000g/kg35BodyCompositionwithDLWLeanBodyMassLBM(kg)=TBW(kg)/0.72FatMassFatMass(kg)=BodyWeight(kg)-LBM(kg)36UseofDoublyLabeledWater•Assessmentoftotal,free-livingenergyexpenditure(evenwildanimals)•Estimateofbodycomposition•Estimateofdailyphysicalactivity,onlywhencombinedwithestimateofRMRusingpredictionequationsorindirectcalorimetry.372H2Odose-to-mothertechnique•Themotherconsumesanaccuratelyweigheddose(30g)D2O•TheD2Omixeswiththemother’sbodywater•ThebabyconsumesD2Oinitsmother’smilk•Salivaissampledfromthemotherandfromthebabyfor2weeks38DoublylabelledwaterallowsyoutoassessTEE•Totalenergymetabolism(TEE)overaperiodofaweek:–includesactivity(EEx)–includesfidgeting–includesTEF–includesRMR•But.Can’tgetindividualcomponents,onlytotalEE.39UnderreportingofenergyintakedietrecordsvsdoublylabelledwaterFFQfoodfrequencyquestionnaire24HR24hrecallDDWdoublylabeledwaterLissneratal2007IJO31,95641Socanaskquestionssuchas:•Howmanycaloriesdoobeseexpendvs.lean•Howmuchfooddoyouneedtosupplytoarmytroopsonpatrol.•Howmanycaloriesdofirefightersuse•Howmanycaloriesdoesalionuse•IfyoualsomeasureorcalculateRMR,•AndyouestimateormeasureTEF,•canestimate:ABOVEBASALEE(=activity)