大学英语四级改革适用（阅读）模拟试卷53（共215题）

大学英语四级改革适用（阅读）模拟试

卷53（共9套）

（共215题）

大学英语四级改革适用（阅读）模拟试

卷第1套

一、词汇理解（本题共70题，每题1.0分，共70分。）

There'saworldpapershortage.There'sanationalboule[Cl],andwe're

runningoutofrawmaterialsliketimberandtin-orsothepaperssay.Well,I'vejust

emptiedmyshoppingbasketaftermy[C2]shoppingtripanditwasfullof

thingsmadefromthese[C3]materials.HalfofwhatI'dboughtIthrewawayat

once;allthoseunnecessarypaperbags,plasticbags,fresh[C4]paperandold

newspaperstheyputthefoodinnowadays.Modernpackagingmakesshoppingcleaner

andmoreconvenient,butatwhat[C5]?Everytimeyouthrowawayapaper

bagyou'rethrowingawaypartofatree—andtreesdon'tgrow[C6]!Atthisrate

(heresoonwon'tbeanytreesleft,andthenwhatshallwedo?Perhapswe'lllearntodo

whatmymotherdid.Sheusedtokeepastoreofpaperbagsinakitchen[C7]

andusethemagainandagainforhershopping.Mostgoodsweresold[C8]

inthosedays.Andtheshopkeeperweighedouttheamountyouwanted.Of

course,liquidgoodshavealwaysbeen[C9]inbottlesorcans,butwhycan'twe

usethemmorethanonce?Ifwe[CIO]allourbottleswewouldsaveontheraw

materialsandenergyneededtomakenewones.It'stimewcstartedtothinkseriously

aboutthegrowingshortageofrawmaterialsintheworldtoday.AdrawerB.seldomC.

weeklyD.reusedE.costF.verifyG.overnightH.wrappingI.enclosedJ.looseK.sold

LshortageM.scarceN.partialO.ban

1、[Cl]

标准答案：L

知识点解析：此处应为名词。结合上一句提到的papershortage和本句中说到的

runningoutofrawmaterials,可以推断空白处应为“缺乏”之义，故答案为shortage<>

2、[C2]

标准答案：c

知识点露析：此处应为形容词。很多外国人通常每周购物一次，这个从本句中第二

个分句itwasfullofthings可见一斑，因此weekly最合适。值得注意的是，weekly

虽然以ly结尾，但它是形容词而不是副词。

3、[C3]

标准答案：M

知识点解析：此处应为形容词。本句中的ihese一词提示这些材料是上两句中说到

的比较缺乏的物资，因此本题答案为scarce。

4、[C4]

标准答案：H

知识点解析：此处应为形容词。本句中unnecessary等词及定语从句theyputthe

foodin提示了本句中列举的都是包装材料，因此本题答案为wrappingo

5、[C5]

标准答案：E

知识点解析：此处应为名词，作介词at的宾语。从上下文的内容可以推断，cost一

词最适合。atwhatcost意为“以什么代价

6、[C6]

标准答案：G

知识点解析：此处应为副词，作grow的状语。根据上下文，该句应指树不会长得

很快，词库中只有overnight合适。don'tgrowovernight意为“不会一夜之间长成”。

7、[C7]

标准答案：A

知识点解析：此处应为名词。根据前文keepastore为paperbags等内容,可以推断

该词是指收藏纸袋的地方，所以draws是本题答案。

8、[C8]

标准答案：J

知识点解析：此处应为副词或形容词，作wcrcsold的状语。根据下一句所述店家

可以按你要的量称给你，可以推断该句应指商品的售卖模式，因此空白处最合适的

单词是looseobesoldloose意为"零卖

9、[C9]

标准答案：K

知识点解析：由前面的havebeen可知此处应为动词的过去分词形式。对比上文可

知，本句提到的是液体商品的包装方法和销售模式与上文提到的其他商品不同，因

此该词应表“包装”或“销售”之义，词库中只有sold最合适。

10、[C10]

标准答案：D

知识点解析：由主句谓语动词wouldsave可知此处应为动词的过去式，充当从句的

谓语。本句是一个虚拟语气句，根据上文的usethemmorethanonce,可得出答案

为reusedo

二、长篇阅读（本题共10题，每题L0分，共10分。）

EvergladesNationalParkA）WhcnmanypeoplethinkofFlorida,imagesofsandy

coastlinesorthemeparkridescometomind.ButaboutanhoursouthofMiamiliesa

naturalwildernessdifferentfromanywhereelseintheUnitedStates.EvergladesNational

Parkisthelargestsubtropicalwildernessinthecountry.Theparkishometoseveralrare

andendangeredspecies.Itisalsothethirdlargestnationalparkinthelowerforty-eight

states,afterDeathValleyandYellowstone.Morethanonemillionpeoplevisitthe

Evergladeseachyear.B）TheEvergladesisconsideredoneofthegreatbiological

wondersoftheworld.Theexpansivewetlandsstretchacrossmorethansixhundred

thousandheciares（公顷）.IlisaplacewhereplantsandanimalsfromtheCaribbeanSea

shareanecosystemwithnativeNorthAmericanspecies.Unlikemostothernational

parks,EvergladesNationalParkwascreatedtoprotectanecosystemfromdamage.The

Evergladesishometothirty-sixspeciesthatareconsideredthreatenedorprotected.They

includetheFloridapanther,theAmericancrocodileandtheWestIndianmanatee.In

addition,morethanthreehundredfiftybirdspeciesandthreehundredspeciesoffresh

andsaltwaterfishlivewithinthepark.TheEvergladesisalsohometofortyspeciesof

mammals（哺乳动物）andfiftyreptile（爬行动物）species.C）Exoticplantscanalsobe

foundintheEverglades.Theyincludewhatissaidtobethelargestgrowthofmangrove

treesinthewesternhalfoftheworld.Gumbo-limbotrees,knownfortheirpeelingred

skin,stranglerfigsandroyalpalmsarealsoamongthearea'splantlife.TheEvergladesis

alsohometothecountry'slargestlivingmahoganytree.Sawgrassgrowsinsomeareasof

thepark.Becareful—itisverysharp,withteethjustlikeasaw.Itcangrowuptofour

meterstall.Withaboutoneandone-halfmetersofrainfalleachyear,plantsandtrees

neverstopgrowingintheEverglades.D）Thedry,winterseasonisthefavoriteofmost

visitors,wheninsectslikemosquitoesarelessofaproblem.Therainyseasonlastsfrom

JunetoNovember.TherearemanywaystoexploretheEverglades.Visitorscouldsee

AmericancrocodileswhilehikingtheAnhingaTrail.TheEvergladesistheonlyplaceon

Earthwherefreshwatercrocodilesandsaltwatercrocodilesliveinthesamearea.Visitors

usingcanoesorairboatsarclikelytoseelargegroupsofwadingbirdslikethewoodstork

orgreatblueheron.ItisevenpossibletoseeflamingosintheEverglades.Thisspring,

EvergladesNationalParklaunchedavisitationprogramtowhatwasonceahighly

restrictedmilitarybase.Parkofficialsareworkingtorecoveramissilebaseusedinthe

1960s.ThebaseplayedaPartInthenucleartensionsbetweentheUnitedStatesandthe

SovietUnion.E）ThegovernmentbuilttheFloridabaseshortlyafterthediscoveryof

Sovietmissilesaboutthreehundredkilometersaway,ontheislandofCuba.Tensions

werehighduringtheCubanmissilecrisis.ButmissilesstoredattheAmericanbasewere

neverfired.Thebasewasclosedandallmissileequipmentwasremovedinthe1970s.

Todayonlythebuildingsremain.Thisyear,thehistoricareahadmanyvisitors,including

formerAmericanservicememberswhorememberthemissilecrisis.Theparkhopesto

offermoretripsnextspring,tohelpsupportthehistoryforthosewholivedthroughitand

forfuturegenerations.F)ExpcrtssaychangestotheEvergladesarcthreateningseveral

differentkindsofwildlife.TheysaythethreatsarearesultofactionstheUnitedStates

governmentbeganmorethanfiftyyearsago,andsettlersbeganevenearlier.The

NationalParkServicesaysearlycolonialsettlersandlanddevelopersthoughtthe

Evergladeshadlittlevalue.Thesettlershadplanstoremovewaterfromtheareaandin

the1880sdevelopersbegandiggingdraincanals.Atthetime,theydidnotunderstandthe

complexityoftheEverglades'ecosystem.Asaresult,theywerenotpreparedforallthe

workandcausedenvironmentalproblems.Theecosystem,however,wasabletosurvive.

G)Evenlargereffortstodrainthewetlandscontinuedbetween1905and1910.Large

areaswerechangedtofannland.Thisledtoincreaseddevelopment,withmorepeople

movingtotheEvergladesandalsomorevisitors.Morechangescamein1948,when

CongressapprovedtheCentralandSouthFloridaProject.Aspartoftheplan,theArmy

CorpsofEngineersbuiltroads,canalsandwater-controlsystemsthroughoutSouth

Florida.Theaimoftheprojectwastoprovidewaterandfloodprotectionfordeveloped

areasandagriculture.Workersbuiltahugesystemofwaterwaysandpumpingstationsto

controltheoverflowofLakeOkeechobee,northoftheEverglades.Today,fiftypercent

ofsouthFlorida'searlywetlandareasnolongerexistPopulationsofwadingbirdshave

beenreducedbyninetypercentWholepopulationsofanimalsareindangerof

disappearing.Theendangeredcreaturesincludethemanatee,theMiamiblackheadsnake,

thewoodstorkandtheFloridapanther.II)Inrecentyears,environmentalexpertshave

learnedaboutthedamagetotheEverglades.Theysaythenaturalbalanceofplantsand

animalshasbeendestroyed.Recently,theObamaadministrationpromisedthreehundred

sixtymilliondollarstopayforEvergladesrestorationthisyear.Theadministrationis

alsoaskingthatCongressapproveanadditionaltwohundredseventy-eightmillion

dollarsfornextyear.Themoneywillhelptosupportprojectsapprovedbythe

governmentnineyearsago.TheprojectsincludeimprovingwetlandsinthePicayune

StrandinSouthwestFloridaandrepairstoLakeOkeechobee'sdam.Untilnow,thestate

ofFloridahasspentthemostmoneyontheproject.I)Anotherthreatbiologistshavebeen

battlingforyearsintheEvergladesisthearea'spopulationofBurmesepythons(large

snakes).Officialsbelievetherearcasmanyasonehundredfiftythousandoftheselarge

snakesintheEverglades.Butthesnakesareaforeignspecies,nativetoSoutheastAsia

OwnersofpythonslefttheirunwantedsnakesintheEvergladesyearsago.Biologistssay

adultpythonsareabletoeatsmalldeerandbobcats.Whenpythonsarefoundinthe

Everglades,theyareoftenkilled.Scientistsarenowexperimentingwithotherwaysto

removethesnakes,includingtrappingmethodsandofferingpaymentstohunters.The

futureoftheEvergladesisnotclear.However,effortstoprotecttheareaarecontinuing

sothatpeoplefromallovertheworldmaycontinuevisitingthisbiologicaltreasure.

11EffortstoprotecttheareawouldbecontinuedthoughthefutureofEvergladesisstill

unknown.

标准答案：I

知识点解析：根据题目信息词TheWureoflheEverglades可定位到I段，该段产数

第2句的isnotclear对应题目的isstillunknown,接着最后一句用however表示转

折，这与题目though引导的让步状语从句语义相同。

12、Inordertoprovidewaterandfloodprotectionfordevelopedareasandagriculture,

theCongressapprovedtheCentralandSouthFloridaPioject.

标准答案：G

知识点解析：根据关键词theCentralandSouthFloridaProject,可直接定位到G

段，该段第4句指出国会通过了这个项目，第6句的Theaimof…was则表明该项

目的目的：为了给开发的地区和农业提供水利和防洪，结合这两句为题目意思，故

选G。

13^TheSovietUnionplacedmissilesontheislandofCubaduringtheCubanmissile

crisis.

标准答案：E

知识点解析：根据题目中的Cubanmissilecrisis等词定位到E段。该段第1句提

到，美国政府在古巴岛上发现了苏联的导弹，这意味着苏联将导弹部署到了古巴岛

上，因此，E段为本题出处。

14、WithanecosystemofplantsandanimalsbothfromCaribbeanSeaandNorth

American,EvergladesNationalParkaimsatprotectinganecosystemfromdamage.

标准答案：B-J^

知识点解析：根据题目中的CaribbeanSea,NorthAmerican可定位到B段。该段第

3句讲到，这里来自加勒比海的动植物与北美本土的物种共享一个生态，题目

With...American与此意思一一致；题目的aimsat…第4句与原文wascreated

to…的语义一致。

15、ThereareonlytenpercentofwadingbirdsstillexistingintheEverglades.

标准答案：G

知识点解析：文章在D段和G段都有提到wadingbirds,其中G段倒数第3句表明

涉水鸟的数量已经减少了90%,这与题目中的现存的涉水鸟只有10%内容相同，

因此，G段为本题出处c

16、TheBurmesepythonsareasnakespeciesthatoriginatedfromSoutheastAsia.

标准答案：I

知识点解析：根据题干中的Burmesepythons等词定位到I段，该段第3句中的

nativelo意为“来自于...”，题目中的originatedfrom与此同义，故选I。

17、MostpeopleprefertovisittheEvergladesinwinter.

标准答案：D-

知识点解析：根据选项中表示季节的winter定位到D段。该段首句的winterseason

isthefavoriie表明冬天去Everglades的人最多，很明显，D为本题答案。

18、TheecosystemoftheEvergladeswasfirstthreatenedbyactionsofcolonialsettlers.

标准答案：F

知识点解析：根据题目中的ecosystem,threat及settlers可定位到F段。该段第2

句提到美国政府和早期移民的活动都对theEverglades的生态造成了威胁，其中移

民的活动所造成的威胁比美国政府来得更早。题目中的wasfirstthreatenedby与这

里的说法一致。

19、LocatedinthesouthofMiami,EvergladesNationalParkisthelargestsubtropical

wildnessintheUS.

标准答案：A

知识点解析：根据题R关键词largestsubtropicalwildness定位到A段。该段第2句

表明其距离迈阿密南部有一小时车程，与题目的locatcdin…语义相同，A段第3

句的内容与题目主干一致，故选A。

20>VisitorstotheEvergladesneedtomindthesawgrassbecauseitmaycutthem.

标准答案：C

知识点解析：根据题干中的sawgrass可定位到C段，该段倒数第3句中的sharp和

saw等词表明saw-grass像锯齿一样锋利，游客应小心以防被划伤，故本题选C。

三、仔细阅读（本题共10题，每题1.0分，共10分。）

Sexprejudicesarebasedonandjustifiedbytheideology（意识形态）thatbiologyis

destiny（命运）.Accordingtotheideology,basicbiologicalandpsychologicaldifferences

existbetweenthesexes.Thesedifferencesrequireeachsextoplayaseparaterolein

sociallife.Womenaretheweakersex-bothphysicallyandemotionally.Thus,theyare

naturallysuitedmuchmoresothanmen,totheperformanceofdomesticduties.A

woman'splace,undernormalcircumstances,iswithintheprotectiveenvironmentofthe

home.Naturehasdeterminedthatwomenplaycare-takerroles,suchaswifeandmother

andhomemaker.Ontheotherhandmenarebestsuitedtogooutintothecompetitive

worldofworkandpolitics,whereseriousresponsibilitiesmustbetakenon.Menarcto

betheproviders;womenandchildrenare"dependents1'.Theideaalsoholdsthatwomen

whowishtoworkoutsidethehouseholdshouldnaturallyfillthesejobsthatareinline

withthespecialcapabilitiesoftheirsex.Itisthusappropriatefbrwomen,notmen,tobe

employedasnurses,socialworkers,elementaryschoolteachers,householdhelpers,and

clerksandsecretaries.Thesepositionsaresimplyanextensionofwomen'sdomesticrole.

Informaldistinctionsbetween"women'swork"and"men'swork"inthelaborforce,

accordingtotheideology,aresimplyafunctionalreflectionofthebasicdifferences

betweenthesexes.Finally,theideologysuggeststhatnaturehasworkedherwillin

anothersignificantway.Forthehumanspeciestosurviveovertime,itsmembersmust

regularlyreproduce.Thus,womenmust,whetheralhomeorinthelaborforce,makethe

mostoftheirphysicalappearance.Sogoestheideology.Itis,ofcourse,nottruethat

basicbiologicalandpsychologicaldifferencesbetweenthesexesrequireeachtoplay

sex-definedrolesinsociallife.Thereismuchevidencethatsexrolesvaryfromsocietyto

society,andthoseroledifferencesthatdoexistarelargelylearned.Buttothedegree

peopleactuallybelievethatbiologyisdestinyandthatnatureintendedformenand

womentomakedifferentcontributionstosociety,sex-definedroleswillbeseenastotally

acceptable.

21、"Biologyisdestiny"inthefirstsentencemeansthat.

A、biologicaldifferencesdeterminesexroles

B、one'ssexisdeterminedbeforehis/herbirth

C^humancannotcontroltheirownfate

D、humanbeingscan'tchangetheirsex

标准答案：A

知识点解析：根据第1句可知，这个说法应与本句开头的sexprejudices相关，另

外，第2、3句是对“biologyisdestiny”这种意识形态的解释，对比四个选项，只有

选项A是与“性别偏见”有关的，因此是正确答案。

22、Jobssuchasnursingandteachingarcconsideredsuitabletorwomenbecause.

A、womenarephysicallyandemotionallyweaker

B、menarenotsuitedforsuchjobs

C>suchjobsgrowoutoftheirpositioninthehome

D、distinctionsaremadebetween"women'swork"and"men'swork”

标准答案：C

知识点解析：根据第2段第3句，可知选项C是本句说法的近义替换。本题最具

干扰性的是选项A,该选项出现在第1段。用于解释为何女性更适合承担家庭内的

责任，因此，它并不是针对本题的直接原因，故不能选。

23、Theauthormostprobablybelievesroledifferencesexistbecause.

A、therearebiologicalandpsychologicaldifferencesbetweenthesexes

B、menandwomencanmakedifferentcontributionstosociety

C、menandwomenmustsurviveincooperation

D、menandwomenacquirethemfromtheircultures

标准答案：D

知识点解析：根据第3段结尾句可以推断出答案。选项A并非是作者的观点，选

项B颠倒了因果关系，选项C虽然是事实但并非此问题的原因。

24、Whichofthefollowingcansumupthemainideaofthewholepassage?

A、isBiologyDestiny?

B、AnImportantIdeology.

C>DifferencesbetweentheSexes.

D、SexRoles.

标准答案：D

知识点解析：通读全文可知.本文讨论了男女两种性别的不同社会角色。本题最具

干扰性的是选项A,事实上，作者并没有对“biologyisdestiny（生理决定命运）”这一

观点提出质疑，只是客观地陈述这一观点，故选项A不对。选项B不够准确，意

义太模糊，选项C只是本文讨论的一部分。

25、Theauthorlooksatsex-definedroleswith.

A、enthusiasticapproval

B、partialacceptance

C、strongdisagreement

D^bittercriticism

标准答案：B

知识点解析：文章第3段倒数第2句是一个以It引导的主语从句，虽然这句话表明

sex-definedroles这种观点不正确.但最后一段却表明作者在某种程度上接受这种

说法，对照这两方面的态度，可见作者对sex-defincdroles既不完全赞成，也不完

全反对，由此可推断B为正确选项。

Sixyearsago,aMiamiwomanwalkingthroughthehallofanofficebuildingcasually

noticedtwomenstandingtogelhei.Severalminutesafteiherleaving,themenmuidcicd

apersonworkinginthebuilding.Policeinvestigatorsdeterminedthatthewomanwasthe

onlywitnesswhohadseenthetwosuspects,andcouldpossiblydescribethem.Inan

interviewwithpolice,hermemoryofthemenproveddisappointinglyunclear.Several

dayslater,psychologistRonaldP.Fisherwasbroughtintoobtainamorecomplete

accountfromthewoman.Fisher'sinterviewproducedabreakthrough（突破）一thewoman

reportedaclearpictureofoneofthesuspects.Shethenrecalledseveraldetailsabouthis

appearances.Thisinformationgavepoliceimportantleadsthatenabledthemtoarrestthe

suspectsandclosethecase.PoliceinvestigatorssoughtthehelpfromFisherbecauseof

hisrichknowledgeinconductingtheso-calledcognitive（认知的）interview,akindof

memory-rebuildingprocess.Initsoriginalform,thecognitiveinterviewfocuseson

guidingwitnessesthroughfourgeneralrecallingtechniques:thinkingaboutphysical

surroundingsandpersonalfeelingsthatexistedatthetimeofpastevents,reporting

everythingthatconiestomindaboutthoseeventsnomatterhowbrokenorunconnected,

retellingeventsinavarietyoftimeorders,beginningtoend,endtobeginning,forwardor

backward,andadoptingdifferentperspectiveswhilerecallingevents.Usually,an

interviewerbeginsthecognitiveapproachbyencouragingthewitnesstotakeanactive

roleinrecallinginformationratherthangivinganswersonlytosomeoneelse'squestions.

Thewitnessfirstdescribeswhathappenedinhisorherownwords,withnointerviev/er

interruptions.Theinterviewerthengoesfurtherwithspecifictechniques,suchashaving

thewitnesstellthedetailsofwhathappenedfromdifferentperspectives.Experiments

withpolicedetectivestrainedinthisdemandinginterviewmethodfindthattheyget

nearly50%moreinformationfromwitnessesthanbeforetraining,whileerrorrates

remainaboutthesame.

26、Whatisthepurposeofthispassage?

A、Togiveanaccountofamurdercaseinanoffice.

B、ToexplainwhyFisherwasinvitedtoapoliceinterview.

C、Todescribehowcognitivemethodhelpsthewomantorecall.

D、Togivethereadersanideaofcognitiveinterview.

标准答案：D

知识点解析：全文的关健词thecognitiveinterview（theinterview）虽然并未在文章一

开头就出现，但在以后的段落中反复出现，因此选项D能概括本文主题。选项A

是第1段涉及的内容，只是本文的引子；选项B是第2段所涉及的内容；选项C

是作者为了介绍cognitiveinterview而使用的例子，并非全文的目的。

27、Thecognitiveinterviewhelpedthewomantorecallmoreby.

A^strengtheninghermemory

B、givingherencouragement

C、rebuildinghermemory

D、givinghermoretime

标准答案：C

知识点解析：根据第3段第1句逗号后的结构可推断出答案。选项B在倒数第2段

第1句提及，但“鼓励”只是认知访谈的第一个步骤，所以不符合题意。选项A和D

文章没有提及。

28、Itcanbeinferredfromthepassagethatinacognitiveinterview,theinterviewer

mainlyplaysa.

A^directing

B、questioning

C、passive

D^secondary

标准答案：A

知识点解析：从第3段第1句提到的conducting和第2句中的guiding两个词看

来，可知认知访谈中访问者主要是引导受访者，也就是选项A。倒数第2段第1句

raiherlhan后的分句已说明受访者不只是回答问题，所以可以推断选项B错误。文

中虽有提及受访者要playanactiverole,但并不等于说访问者是被动或次要角色，

故选项C和D不对。

29、Whatisthekeypointofthecognitiveinterview?

A、Theinterviewershouldinterruptthewitnessfromtimetotime.

B、Thewitnessisencouragedtotakeanactiveroleinrecallinginformation.

C、Theinterviewshouldtakeplaceoutsidethepolicestation.

D^Thewitnessshouldrecalldetailsatthesceneoftheevent.

标准答案：B

知识点解析：文章第4段第1句明确指出了答案，选项A与该段第2句相悖，选

项C和D在文中并未提及。

30、Policetrainedinthecognitiveinterviewmethodcan.

A、getmoreinformationfromthewitnessthanbefore

B、decreasetheerrorrate

C^solvethecasesmorequickly

D、usethemethodmoreskillfullythanthepsychologists

标准答案：A

知识点解析：本题考查复合句的理解。最后一段是一个宾语从句，该宾语从句表明

选项A正确，而包含在宾语从句中的并列分句（由while连接）可证明选项B的信息

都不准确。选项C和D在文中都没有相关信息。

大学英语四级改革适用(阅读)模拟试

卷第2套

一、长篇阅读(本题共30题，每题7.0分，共30分。)

GettingThin-forGoodA)Justabouteveryonehasbeenonadietatonetimeoranother,

andmillionsofushavelearnedthattheweightweloseisalltooeasilyregained.Stillfew

peoplequestionthewisdomofdieting.Afterall,wereason,theworstthatcanhappenis

thatwellregaintheweightwc'vclost—thenwccansimplygoonadietagain.B)But

somenewresearchsuggeststhereisarisk:yo-yodietingmayseriouslydistortthebody's

weight-controlsystem.Themoredietsyougoon,theharderitmaybecometolose

weight.Evenworse,newevidenceindicatesthatrepeatedcyclesoflosingandgaining

weightmayraisetheriskofheartproblems.C)Thislastpossibilityisespecially

disturbing.Aspartofa25-yearstudythatmonitored1,959men,researchersatthe

UniversityofTexasSchoolofPublicHealthinHoustonreportedinMarch1987thatthe

menshowinglargeup-and-downweightchangeshadtwicetheriskofheartdiseaseas

thosewithonlysmallchangesinweight.OnepaperfromtheFramingham(Mass.)Hcait

Study,whichhasmonitoredmorethan5,000peoplefor40years,alsoprovidestroubling

information:peoplewholosttenpercentoftheirbodyweighthadabout20percent

reductioninriskofheartdisease-butpeoplewhogained10percentraisedtheriskby30

percent.Thesenumbersfurthersuggestthatgoingfrom150to135pounds,andbackto

150again,couldleaveyouwithahigherheart-diseaseriskthanyoustartedwith.

D)Whcnyoucutcaloricsandloseweight,yourbodywillprotectitselfbyreducingyour

basalmetabolicrate(BMR).Thisisthemeasureoftheenergyusedforroutinefunctions

suchasbreathingandcellrepair—roughly60to75percentoftheenergyconsumedby

thebody.Duringseveredieting,yourBMRdropswithin24hoursandcandeclineafull

20percentwithintwoweeks.Thismetabolicdeclineisonereasondietersoftenreacha

steadyunchangingperiod,andfindthatthesamecaloricintakewhichmeltedpounds

earliernowproducesnoweightloss.E)Thebodyadaptstodietinginotherways.The

enzymelipoproteinlipase(脂肪酶),achemicalinthebody,whichcontrolshowmuchfat

isstoredinfatcell,maybecomemoreactiveinsomeoverweightpeopleaftertheyhave

lostweight.Thatwouldmakethebodymoreefficientalfatstorage-exactlywhatthe

dieterdoesn'twant.Andthischange,likethedropinBMR,maybepartofthereason

dietersfrequentlyregaintheirlostweight.F)Myinterestintheyo-yoproblembeganin

1982,whenmycolleaguesThomasWaddenandAlbenStunkardandIwere

experimentingwithvery-low-caloriediets-800caloriesorfewerperday.Wehopedthat

patientsinourcliniccouldloselargeamountsofweightrapidly,thenkeeptheweight

losswithabehavior-modificationprogram.G)Wefound,however,thatsomepeoplelost

weightrapidly,someslowly;somelostforawhileandthenstoppedlosing.Onewoman,

Marie,begantheprogramat230pounds,reducedto192pounds,andthen"hitawall",

eventhoughshestayedonherdietandwalkedtwomilesaday.Marie,likemanyothers

inourprogram,hadbeenayo-yodieter,andtheytendedtohavethemostdifficultyin

losingweight.H)Toseeifsuchdietingcouldreallychangethebodythisway,other

researchersandIbegantostudyweightchangesinanimals.Wefedagroupofratsa

high-fatdietuntiltheybecameobese.Thenwechangedtheirdietsrepeatedlytomake

themloseweight,regain,loseagainandregainagain.I)Theresultsweresurprising.The

firsttimetheratslostweight,ittook21daysfbrthemtogofromobesetonormalweight.

Ontheirseconddiet,ittook46days,eventhoughtheratsconsumedexactlyasmany

calories.J)Witheachyo-yo,itbecameeasierfortheratstoregain.Afterthefirstdiet,

theytook46daystobecomeobeseagain;aftertheseconddiet,theytookonly14days.In

otherwordsonthesecondyo-yocycle,ittookmorethantwiceaslongtoloseweight,

andonlyone-thirdaslongtoregainit.K)Surprised,ourgroupcontactedHarvardsurgeon

GeorgeBlackburn,apioneerintheuseolvery-low-caloriediets.Blackburnandhis

colleaguesreviewedtherecordsof140dieterswhohadbeenthroughtheirweight-control

clinic,hadlostweightandregainedit-andhadreturnedforasecondtry.Therecords

showedthedietershadlostanaverageof2.3poundsaweekthefirsttime,butonly1.3

poundsaweekthesecondtime.L)FouryearsagowebegantheWeightCyclingProject,

amajorstudythatincludessomeofthecountry1sleadingobesityresearchers.Wcknow

thatpeoplewholoseweightbydietingonlyandwithoutanexerciseprogramcanlosea

considerableamountofmuscle.Buithen,iftheygainweightback,theymayregainless

muscleandmorefat.Whilethereasonisn'tclear,itmaybeeasierforthebodytopulfat

onthantorebuildlostmuscle.We'reaskingifyo-yodietersmaylosefatfromonepartof

thebodyandregainitelsewhere.Forinstance,accordingtoourpreparatorystudiesin

animals,theycouldmovefattotheabdomen.Andresearchshowsthatabdominalfai

raisestheriskofheartdiseaseanddiabetesmorethanfataroundthehipsandthighsdoes.

M)Noncofthismeansthatdietingisineffectiveorfoolish.Forthosewhoarc20percent

ormoreoverweight,therearegoodreasonstoreduce:successfulweightlosscanlower

bloodpressureandcholesterol,helpcontrolbloodsugarindiabeticsandenablepeopleto

feelbetteraboutthemselves.Butthenewresearchdoessuggestthatdietingmustbe

takenseriouslybypeopleatanyweight.N)Italsomeansthatdietingaloneisnotthebest

waytoweightcontrol.Whenaweight-lossprogramincludesexercise,youlosemorefat

andlessmuscle,andyou'renotlikelytogaintheweightback.Thatrsbecauseexercise

mayhelpresistthephysiologicalchangesthattendtocomefromyo-yodieting.O)Given

thepotentialrisksofyo-yodieting,anyonewhodietsshouldbeespeciallycarefulnotto

gaintheweightback.Beforeyoudiet,askyourselfhov/determinedyouare;thenset

reasonablegoals.P)Permanentweightlossshouldbethemaingoal,soselectaprogram

thatwillhelpyouchangeyourlife-style.Becarefulofpopulardietprogramsdesigned

forrapidweightlossandfilledwithsenselesstricks,suchasgoingonandoffadiet,

eating"magic"foodsandsoon.Aprogramshouldfocusonsensiblechangesinnutrition

andlife-style.Thebest