IsBreakfastReallytheMostImportantMealoftheDay?
A) Alongwitholdclassicslike "carrotsgiveyounightvision" and "Santadoesn'tbringtoystomisbehavingchildren", oneofthemostwell-wornphrasesoftiredparentseverywhereisthatbreakfastisthemostimportantmealoftheday. Manyofusgrowupbelievingthatskippingbreakfastisaseriousmistake, evenifonlytwothirdsofadultsintheUKeatbreakfastregularly, accordingtotheBritishDieteticAssociation, andaroundthree-quartersofAmericans.
B) "Thebodyusesalotofenergystoresforgrowthandrepairthroughthenight," explainsdietspecialistSarahElder. "Eatingabalancedbreakfasthelpstoupourenergy, aswellasmakeupforproteinandcalciumusedthroughoutthenight." Butthere'swidespreaddisagreementoverwhetherbreakfastshouldkeepitstopspotinthehierarchy (等级) ofmeals. Therehavebeenconcernsaroundthesugarcontentofcerealandthefoodindustry'sinvolvementinpro-breakfastresearch -- andevenoneclaimfromanacademicthatbreakfastis "dangerous".
C) What'sthereality? Isbreakfastanecessarystarttothedayoramarketingtacticbycerealcompanies? Themostresearchedaspectofbreakfast(andbreakfast-skipping) hasbeenitslinkstoobesity. Scientistshavedifferenttheoriesastowhythere'sarelationshipbetweenthetwo. InoneUSstudythatanalysedthehealthdataof 50,000 peopleoversevenyears, researchersfoundthatthosewhomadebreakfastthelargestmealofthedayweremorelikelytohavealowerbodymassindex (BMI) thanthosewhoatealargelunchordinner. Theresearchersarguedthatbreakfasthelpsreducedailycalorieintakeandimprovethequalityofourdiet -- sincebreakfastfoodsareoftenhigherinfibreandnutrients.
D) Butaswithanystudyofthiskind, itwasunclearifthatwasthecause -- orifbreakfast-skipperswerejustmorelikelytobeoverweighttobeginwith. Tofindout, researchersdesignedastudyinwhich 52 obesewomentookpartina 12-weekweightlossprogramme. Allhadthesamenumberofcaloriesovertheday, buthalfhadbreakfast, whiletheotherhalfdidnot. Whattheyfoundwasthatitwasn'tbreakfastitselfthatcausedtheparticipantstoloseweight: itwaschangingtheirnormalroutine.
E) Ifbreakfastaloneisn'taguaranteeofweightloss, whyistherealinkbetweenobesityandbreakfast-skipping? AlexandraJohnstone, professorofappetiteresearchattheUniversityofAberdeen, arguesthatitmaysimplybebecausebreakfast-skippershavebeenfoundtobelessknowledgeableaboutnutritionandhealth. "Therearealotofstudiesontherelationshipbetweenbreakfasteatingandpossiblehealthoutcomes, butthismaybebecausethosewhoeatbreakfastchoosetohabituallyhavehealth-enhancingbehaviourssuchasregularexerciseandnotsmoking," shesays.
F) A 2016 reviewof 10 studieslookingintotherelationshipbetweenbreakfastandweightmanagementconcludedthereis "limitedevidence" supportingorrefuting (反驳) theargumentthatbreakfastinfluencesweightorfoodintake, andmoreevidenceisrequiredbeforebreakfastrecommendationscanbeusedtohelppreventobesity.
G) ResearchesfromtheUniversityofSurreyandUniversityofAberdeenarehalfwaythroughresearchlookingintothemechanismsbehindhowthetimeweeatinfluencesbodyweight. Earlyfindingssuggestthatabiggerbreakfastisbeneficialtoweightcontrol. Breakfasthasbeenfoundtoaffectmorethanjustweight. Skippingbreakfasthasbeenassociatedwitha 27% increasedriskofheartdisease, a 21% higherriskoftype 2 diabetesinmen, anda 20% higherriskoftype 2 diabetesinwomen. Onereasonmaybebreakfast'snutritionalvalue -- partlybecausecerealisfortified (增加营养价值) withvitamins. Inonestudyonthebreakfasthabitsof 1,600 youngpeopleintheUK, researchersfoundthatthefibreandmicronutrientintakewasbetterinthosewhohadbreakfastregularly. TherehavebeensimilarfindingsinAustralia, Brazil, CanadaandtheUS.
H) Breakfastisalsoassociatedwithimprovedbrainfunction, includingconcentrationandlanguageuse. Areviewof 54 studiesfoundthateatingbreakfastcanimprovememory, thoughtheeffectsonotherbrainfunctionswereinconclusive. However, oneofthereview'sresearchers, MaryBethSpitznagel, saysthereis "reasonable" evidencebreakfastdoesimproveconcentration -- therejustneedstobemoreresearch. "Lookingatstudiesthattestedconcentration, thenumberofstudiesshowingabenefitwasexactlythesameasthenumberthatfoundnobenefit," shesays. "Andnostudiesfoundthateatingbreakfastwasbadforconcentration."
I) What'smostimportant, someargue, iswhatweeatforbreakfast. High-proteinbreakfastshavebeenfoundparticularlyeffectiveinreducingthelongingforfoodandconsumptionlaterintheday, accordingtoresearchbytheAustralianCommonwealthScientificandIndustrialResearchOrganisation. WhilecerealremainsafirmfavouriteamongbreakfastconsumersintheUKandUS, arecentinvestigationintothesugarcontentof'adult'breakfastcerealsfoundthatsomecerealscontainmorethanthree-quartersoftherecommendeddailyamountoffreesugarsineachportion, andsugarwasthesecondorthirdhighestingredientincereals.
J) Butsomeresearchsuggestsifwe'regoingtoeatsugaryfoods, it'sbesttodoitearly. Onestudyrecruited 200 obeseadultstotakepartina 16-week-longdiet, wherehalfaddeddesserttotheirbreakfast, andhalfdidn't. Thosewhoaddeddessertlostanaverageof 40 poundsmore -- however, thestudywasunabletoshowthelong-termeffects. Areviewof 54 studiesfoundthatthereisnoconsensusyetonwhattypeofbreakfastishealthier, andconcludedthatthetypeofbreakfastdoesn'tmatterasmuchassimplyeatingsomething.
K) Whilethere'snoconclusiveevidenceonexactlywhatweshouldbeeatingandwhen, theconsensusisthatweshouldlistentoourownbodiesandeatwhenwe'rehungry. "Breakfastismostimportantforpeoplewhoarehungrywhentheywakeup," Johnstonesays. "Eachbodystartsthedaydifferently -- andthoseindividualdifferencesneedtoberesearchedmoreclosely," Spitznagelsays. "Abalancedbreakfastisreallyhelpful, butgettingregularmealsthroughoutthedayismoreimportanttoleavebloodsugarstablethroughtheday, whichhelpscontrolweightandhungerlevels," saysElder. "Breakfastisn'ttheonlymealweshouldbegettingright."
36. Accordingtooneprofessor, obesityisrelatedtoalackofbasicawarenessofnutritionandhealth.
37. Somescientistsclaimthatpeopleshouldconsumetherightkindoffoodatbreakfast.
38. Opinionsdifferastowhetherbreakfastisthemostimportantmealoftheday.
39. Ithasbeenfoundthatnotcatingbreakfastisrelatedtotheincidenceofcertaindiseasesinsomecountries.
40. Researchersfounditwasachangeineatinghabitsratherthanbreakfastitselfthatinducedweightloss.
41. Tokeeponeselfhealthy, eatingbreakfastismoreimportantthanchoosingwhattoeat.
42. Itiswidelyconsideredwrongnottoeatbreakfast.
43. Moreresearchisneededtoprovethatbreakfastisrelatedtoweightlossorfoodintake.
44. Pecoplewhoprioritisebreakfaststendtohavelowercaloriebuthighernutritionalintake.
45. Manystudiesrevealthateatingbreakfasthelpspeoplememoriseandconcentrate.