英语演讲稿:TED英语演讲稿：为什么节食减肥没效果？是英语演讲稿的经典，只要你仔细了解并细心体会其中的技巧，你一定能够做好一个完美的演讲！
简介：在美国，80%的女孩在她们10岁的时候便开始节食。神经学家sandraaamodt结合自己的亲身经历，讲述大脑是如何控制我们的身体的。节食减肥为何没效果?来听听她的说法吧!
threeandahalfyearsago,imadeoneofthebestdecisionsofmylife.asmynewyear'sresolution,igaveupdieting,stoppedworryingaboutmyweight,andlearnedtoeatmindfully.nowieatwheneveri'mhungry,andi'velost10pounds.
thiswasmeatage13,whenistartedmyfirstdiet.ilookatthatpicturenow,andithink,youdidnotneedadiet,youneededafashionconsult.(laughter)butithoughtineededtoloseweight,andwhenigaineditback,ofcourseiblamedmyself.andforthenextthreedecades,iwasonandoffvariousdiets.nomatterwhatitried,theweighti'dlostalwayscameback.i'msuremanyofyouknowthefeeling.
asaneuroscientist,iwondered,whyisthissohard?obviously,howmuchyouweighdependsonhowmuchyoueatandhowmuchenergyyouburn.whatmostpeopledon'trealizeisthathungerandenergyusearecontrolledbythebrain,mostlywithoutyourawareness.yourbraindoesalotofitsworkbehindthescenes,andthatisagoodthing,becauseyourconsciousmind--howdoweputthispolitely?--it'seasilydistracted.it'sgoodthatyoudon'thavetoremembertobreathewhenyougetcaughtupinamovie.youdon'tforgethowtowalkbecauseyou'rethinkingaboutwhattohavefordinner.
yourbrainalsohasitsownsenseofwhatyoushouldweigh,nomatterwhatyouconsciouslybelieve.thisiscalledyoursetpoint,butthat'samisleadingterm,becauseit'sactuallyarangeofabout10or15pounds.youcanuselifestylechoicestomoveyourweightupanddownwithinthatrange,butit'smuch,muchhardertostayoutsideofit.thehypothalamus,thepartofthebrainthatregulatesbodyweight,therearemorethanadozenchemicalsignalsinthebrainthattellyourbodytogainweight,morethananotherdozenthattellyourbodytoloseit,andthesystemworkslikeathermostat,respondingtosignalsfromthebodybyadjustinghunger,activityandmetabolism,tokeepyourweightstableasconditionschange.that'swhatathermostatdoes,right?itkeepsthetemperatureinyourhousethesameastheweatherchangesoutside.nowyoucantrytochangethetemperatureinyourhousebyopeningawindowinthewinter,butthat'snotgoingtochangethesettingonthethermostat,whichwillrespondbykickingonthefurnacetowarmtheplacebackup.
yourbrainworksexactlythesameway,respondingtoweightlossbyusingpowerfultoolstopushyourbodybacktowhatitconsidersnormal.ifyoulosealotofweight,yourbrainreactsasifyouwerestarving,andwhetheryoustartedoutfatorthin,yourbrain'sresponseisexactlythesame.wewouldlovetothinkthatyourbraincouldtellwhetheryouneedtoloseweightornot,butitcan't.ifyoudolosealotofweight,youbecomehungry,andyourmusclesburnlessenergy.dr.rudyleibelofcolumbiauniversityhasfoundthatpeoplewhohavelost10percentoftheirbodyweightburn250to400calorieslessbecausetheirmetabolismissuppressed.that'salotoffood.thismeansthatasuccessfuldietermusteatthismuchlessforeverthansomeoneofthesameweightwhohasalwaysbeenthin.
fromanevolutionaryperspective,yourbody'sresistancetoweightlossmakessense.whenfoodwasscarce,ourancestors'survivaldependedonconservingenergy,andregainingtheweightwhenfoodwasavailablewouldhaveprotectedthemagainstthenextshortage.overthecourseofhumanhistory,starvationhasbeenamuchbiggerproblemthanovereating.thismayexplainaverysadfact:setpointscangoup,buttheyrarelygodown.now,ifyourmotherevermentionedthatlifeisnotfair,thisisthekindofthingshewastalkingabout.(laughter)successfuldietingdoesn'tloweryoursetpoint.evenafteryou'vekepttheweightoffforaslongassevenyears,yourbrainkeepstryingtomakeyougainitback.ifthatweightlosshadbeenduetoalongfamine,thatwouldbeasensibleresponse.inourmodernworldofdrive-thruburgers,it'snotworkingoutsowellformanyofus.thatdifferencebetweenourancestralpastandourabundantpresentisthereasonthatdr.yonifreedhoffoftheuniversityofottawawouldliketotakesomeofhispatientsbacktoatimewhenfoodwaslessavailable,andit'salsothereasonthatchangingthefoodenvironmentisreallygoingtobethemosteffectivesolutiontoobesity.
sadly,atemporaryweightgaincanbecomepermanent.ifyoustayatahighweightfortoolong,probablyamatterofyearsformostofus,yourbrainmaydecidethatthat'sthenewnormal.
psychologistsclassifyeatersintotwogroups,thosewhorelyontheirhungerandthosewhotrytocontroltheireatingthroughwillpower,likemostdieters.let'scallthemintuitiveeatersandcontrolledeaters.theinterestingthingisthatintuitiveeatersarelesslikelytobeoverweight,andtheyspendlesstimethinkingaboutfood.controlledeatersaremorevulnerabletoovereatinginresponsetoadvertising,super-sizing,andtheall-you-can-eatbuffet.andasmallindulgence,likeeatingonescoopoficecream,ismorelikelytoleadtoafoodbingeincontrolledeaters.childrenareespeciallyvulnerabletothiscycleofdietingandthenbinging.
severallong-termstudieshaveshownthatgirlswhodietintheirearlyteenageyearsarethreetimesmorelikelytobecomeoverweightfiveyearslater,eveniftheystartedatanormalweight,andallofthesestudiesfoundthatthesamefactorsthatpredictedweightgainalsopredictedthedevelopmentofeatingdisorders.theotherfactor,bytheway,thoseofyouwhoareparents,wasbeingteasedbyfamilymembersabouttheirweight.sodon'tdothat.(laughter)
ileftalmostallmygraphsathome,buticouldn'tresistthrowinginjustthisone,becausei'mageek,andthat'showiroll.(laughter)thisisastudythatlookedattheriskofdeathovera14-yearperiodbasedonfourhealthyhabits:eatingenoughfruitsandvegetables,exercisethreetimesaweek,notsmoking,anddrinkinginmoderation.let'sstartbylookingatthenormalweightpeopleinthestudy.theheightofthebarsistheriskofdeath,andthosezero,one,two,three,fournumbersonthehorizontalaxisarethenumberofthosehealthyhabitsthatagivenpersonhad.andasyou'dexpect,thehealthierthelifestyle,thelesslikelypeopleweretodieduringthestudy.nowlet'slookatwhathappensinoverweightpeople.
theonesthathadnohealthyhabitshadahigherriskofdeath.addingjustonehealthyhabitpullsoverweightpeoplebackintothenormalrange.forobesepeoplewithnohealthyhabits,theriskisveryhigh,seventimeshigherthanthehealthiestgroupsinthestudy.butahealthylifestylehelpsobesepeopletoo.infact,ifyoulookonlyatthegroupwithallfourhealthyhabits,youcanseethatweightmakesverylittledifference.youcantakecontrolofyourhealthbytakingcontrolofyourlifestyle,evenifyoucan'tloseweightandkeepitoff.
dietsdon'thaveverymuchreliability.fiveyearsafteradiet,mostpeoplehaveregainedtheweight.fortypercentofthemhavegainedevenmore.ifyouthinkaboutthis,thetypicaloutcomeofdietingisthatyou'remorelikelytogainweightinthelongrunthantoloseit.
ifi'veconvincedyouthatdietingmightbeaproblem,thenextquestionis,whatdoyoudoaboutit?andmyanswer,inaword,ismindfulness.i'mnotsayingyouneedtolearntomeditateortakeupyoga.i'mtalkingaboutmindfuleating:learningtounderstandyourbody'ssignalssothatyoueatwhenyou'rehungryandstopwhenyou'refull,becausealotofweightgainboilsdowntoeatingwhenyou'renothungry.howdoyoudoit?giveyourselfpermissiontoeatasmuchasyouwant,andthenworkonfiguringoutwhatmakesyourbodyfeelgood.sitdowntoregularmealswithoutdistractions.thinkabouthowyourbodyfeelswhenyoustarttoeatandwhenyoustop,andletyourhungerdecidewhenyoushouldbedone.ittookaboutayearformetolearnthis,butit'sreallybeenworthit.iamsomuchmorerelaxedaroundfoodthanihaveeverbeeninmylife.ioftendon'tthinkaboutit.iforgetwehavechocolateinthehouse.it'slikealienshavetakenovermybrain.it'sjustcompletelydifferent.ishouldsaythatthisapproachtoeatingprobablywon'tmakeyouloseweightunlessyouofteneatwhenyou'renothungry,butdoctorsdon'tknowofanyapproachthatmakessignificantweightlossinalotofpeople,andthatiswhyalotofpeoplearenowfocusingonpreventingweightgaininsteadofpromotingweightloss.let'sfaceit:ifdietsworked,we'dallbethinalready.(laughter)
whydowekeepdoingthesamethingandexpectingdifferentresults?dietsmayseemharmless,buttheyactuallydoalotofcollateraldamage.atworst,theyruinlives:weightobsessionleadstoeatingdisorders,especiallyinyoungkids.intheu.s.,wehave80percentof10-year-oldgirlssaythey'vebeenonadiet.ourdaughtershavelearnedtomeasuretheirworthbythewrongscale.evenatitsbest,dietingisawasteoftimeandenergy.ittakeswillpowerwhichyoucouldbeusingtohelpyourkidswiththeirhomeworkortofinishthatimportantworkproject,andbecausewillpowerislimited,anystrategythatreliesonitsconsistentapplicationisprettymuchguaranteedtoeventuallyfailyouwhenyourattentionmovesontosomethingelse.
letmeleaveyouwithonelastthought.whatifwetoldallthosedietinggirlsthatit'sokaytoeatwhenthey'rehungry?whatifwetaughtthemtoworkwiththeirappetiteinsteadoffearingit?ithinkmostofthemwouldbehappierandhealthier,andasadults,manyofthemwouldprobablybethinner.iwishsomeonehadtoldmethatbackwheniwas13.
thanks.
(applause)