may state one servingcontains 110 calories, represents kilocalories. For example,afoodlabel calories, butinactuality thenumberreported On foodlabels,kilocalories (kcal)arecalled kilocalorie; one kilocalorie equals 1000 calories. in 1000-caloriemetricunits,knownas a unit offoodenergy.Thisenergyisexpressed of kilocalories.Theterm . You may have heard of calories instead temperature ofaliterwateronedegree the amountofenergyrequiredtoraise kilocalories (kcal).Akilocalorieisdefinedas The we consume is measured in excess energyisstoredinourbodiesasfat. energy burnedandconsumedbecause or toolittle.Weneedtofindabalancebetween energy forourbodiestofunction;nottoomuch our lives.Theideais to consume just enough energy, andthatamountchangesthroughout week. Eachpersonneedsadifferentamountof We useenergy24hoursaday,sevendays energy? with weeatprovidesus Did youknowthatthe Energy Equilibrium Energy Balance calorie referstoa the riseintemperature withathermometer. A dioxide andwater.The calorimetermeasures These reactionsresultin theformationofcarbon break, releasingenergy intheformofheat. the ,carbon andhydrogenbonds break downfood.Whenthefoodisheated in because itmimicsthemethodourbodyuses to potential energy.Thebombcalorimeterisused of energyanobjectpossiblyhasisknown as of potentialenergyinthefood.Theamount when food is burned, which provides an estimate bomb calorimetermeasurestheheatreleased food, scientistscanusea To findoutexactlyhowmanycaloriesarein approximately equalto0.25kilocalories. way tomeasurethesameitem.Onekilojouleis measurement ofkilojoules same askilocalories.Internationally,theenergy States useCalories(capitalized),whichisthe calories. However,foodlabelsintheUnited which meansthefoodreallycontains110,000 bomb calorimeter. A is used.Itanother

Energy Balance Energy Balance weight(numberofgram)bythekcalper To findthekcalinfoodyouneedmultiply of fatitwillhave(4x15)+(4x2)+(9x11)=167kcal. , 2gramsofprotein,and11 gram. For example if a food contains 15 of 4 kcalpergram,whilefatcontains9 and .Carbohydratesproteinscontain three macronutrients;carbohydrates,protein, based on content ofafoodistocalculatekilocalories Another methodusedtodeterminethecalorie Explorations Labofthischapter. more abouttheseunitsofenergyinthe 2700 caloriesor2.7kcalories.Youwilllearn the food is being burned, the food is around degrees Celsiusandto44while temperature of 100gwater changes from17 rises for 1gram of water. For example, if the calorie isequaltoeachdegreethetemperature macronutrient content. There are Food affect ourbodiesbasedontheircomposition! health. Let’sfindouthowdifferentfoodsmay healthy eatinghabitsisveryimportantforour Department of Agriculture (USDA). Practicing Try looking for sourcesfromtheUnited States eating, butchoosingtherightonemaybetricky. we canfindinformationaboutwhatshouldbe body. Therearemanydifferentsourcesinwhich minerals. We need these nutrients for a healthy nutrients intheformofprotein,vitamins,and with fatorsugar.Thesefoodshaveveryfew be lowincalories,thosecaloriesmayloaded very importantfor our health. While a food may Understanding thenutrientcontentoffoodsis grams by4kcalpergram(15x=60). the foodabovecanbefoundbymultiplying15 gram. Forexample,thekcalfromcarbohydratein 4. 3. 2. 1. Think AboutIt What isthedifferencebetweena How manykilocalorieswouldittaketoraise5litersofwater2degreesCelsius?______How manykilocalorieswouldittaketoraise10litersofwater1degreeCelsius?______The energyneededtoraise1literofwaterdegreeCelsiusisa______. kilocalorie andacalorie?

Energy Balance