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Intermittent Fasting & Calorie Restriction. Can they help me live longer? Lose weight? by Zoë Harcombe
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Introduc7on
everyotherday;ordoing this everyfew days or acoupleofdaysaweekandsoon.
A recent UK TV programme (Monday 6th August 2012) has generated much interest about Calorie Restricon and Intermient Fa s ng . T he p ro gra mm e wa s a H or iz on documentary, by Michael Mosley, called "Eat, Fast and Live Longer"1 (The comma is very important!) The programme won't be on BBC iplayerforeverandpeople outside the UKcan't get iplayer, so let's hope YouTube copies stay upforawhile 2. Otherpeople havepostedthe programme in parts on YouTube so do try pu[ngin theprogrammetle ifthe links inthe referencenotesnolongerwork.
) The frequency with which IFis done is the final variant.This is driven toanextentby (2)- an every other day restricon is obviously repeated every other day. However someone canchooseto fast for betweenone and a few days everyweek,everymonth,everyquarteror asdesired.
Quickdefini7ons Let's just differenate between the twoterms beforewegoanyfurther: Calorie Restricon(CR)is longterm restricon of calories below that neededon a daily basis by a person.As a generalrule, CR involves an approximate 30%calorie deficit fromthedaily requirement. IntermientFasng(IF)shouldbe,as the name suggests,fasng(eangnothing)forperiodsof me e ve ry n ow a nd a ga in . H ow ev er , Intermient Fasng has come to mean many differentthings.Threethingscanvary: 1) Fasng does not necessarily mean eang nothing (drinking only water). Fasng is now taken to mean either eang nothing or eang substanallyless than the recommendedintake (25% of the recommendeddailycalorie intake servesasacommonguide). 2) ThelengthofmeforwhichIFisundertaken canvary. Some regimes have a 3-5 day literal fast (water only - or a cup-a-soup, as we will see). Otheropons include fasng/eang lile
The permutaons of 1, 2 and 3 make for n um er ou s o p on s a va il ab le t o p eo pl e interested in Intermient Fasng. Should anyone choose to do IF, they may be well advised to develop their own plan, taking the oponmostlikelytoworkforthemfromfasng vs. eang lile,how long the fast will beand howoenitwillbeundertaken.
ProgrammeSynopsis Just in case you can't see the Horizon programme, or if you don't have an hour to spare - here's a synopsis of the documentary. The synopsis also serves as an excellent introducon to the whole topic of Calorie Restricon and Intermient Fasng - Mosley has goneto the leadinginstuons and metthe keyresearchers in these fields andthis is a great placetostart: Michael Mosley is a great narratorandan 'upfor-it'guy.Ifyouhaveseenotherprogrammes ofhis forHorizon(TheTruthaboutexercise3,10 things youshould knowabout losingweight4), Mosleydoes the experiments himself,has blood takenandgets toldhowmuchofhis bodyisfat (toomuchbasically!) The programme opens with Mosley meeng 101 year old Fauja Singh who is running the London Marathon5. Mosley notes that 7,000 people in their 50s are running the London marathonand7peopleover80.Singhtookup
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running in his 80s. Singh puts his longevity down to eang 'child-sized' porons. This hypothesisisnotchallenged. Mo sl ey no tes that "c learl y genes pl ay a significant part" in longevity and this needs emphasis atthis stage,as itis barelymenoned againthroughouttheprogramme. MosleyheadsofftoAmerica andnotes that life expectancy rose by "a remarkable six years" du ri ng "t he da rk es t ye ars o f t he Gr eat Depression"(1929-1933). Mosley notes thatit was at this me - back in th e 1930s - t hat nu tri on is ts a t Corn el l University first started looking at animal experiments with regard to longevity. They severely restricted how much some animals (rats) ate and found that they lived much longer. Clive McCay was the lead researcher and an arcle aboutthe studynoted thatsevere food restricon from just a+e r wea ning "delayed physical and sexual maturaon and led t o very l arge i ncreas es i n max imu m lifespan"6. Please not e how early Calorie Res tr ic o n wa s st art ed in li fe an d t he consequence for thegrowth ofthe rats -we'll comebacktothis. Washington University is the next port of call for Mosley, as he meets sciensts looking at Calorie Restricon and longevity in humans. Professor LuigiFontana isthe manwho greets Mosley at theuniversity.(Fontana looks like a middle distancerunner - very small and lean). The Washingtonteamarelookingatwhatthey admit is severe Calorie Restricon (CR) every single day.The researchers andparcipants try to get opmal nutrionfromthe lower intake and this is presented as "lots of fruit and vegetables." However, anyone who knows the nutrional content of food knows that animal
foods beat plant foods for protein, essenal fats,vitaminsandminerals7. We meet Joe/Joseph who, for a decade, has eaten approximately 1,900 calories a day. The USA recommended calorie intake for each gender by ageandacvity level was set outin the 2010 Dietary Guidelines for Americans8. If Joe is sedentary he is esmated to need approximately 2,000-2,200 calories per day; if he is moderately acvehe is esmatedtoneed 2,200-2,400calories perdayand,ifacve,he is esmatedtoneed2,400-2,800calories perday. Joeis happy to report that his brother weighs 100lbmorethanhe does.We seeJoe preparing breakfastin his kitchen- a mixingbowlsize of berries withapple peel added-he throws away the non-peel partofthe apple forits highsugar content. This may be sensible, but with 5.6 billion pounds of pescides used worldwide eachyear9, Joeshould worry about allaspects ofhealth. Mosley esmates that he personally has averaged around2,300 calories a day "quitea few of them doughnuts and burgers", he admits. Joe and Michael arebothin their50s. Wedon'tknowtheirheights,butJoeweighsin at134lbs (that is ny for a man and not very aracve if you don't mind a personal view) and Michael over 180lbs (they didn't give a precisenumberforMichael). They compete withtwotests thatwe candoat homeandthenabloodtestcomparison.Test oneis tostandonone legwith eyes closed for as longas possible.Michaelcan onlymanagea few seconds; Joe goes well past 30 seconds before they stop the test (do watch the different techniques though - Michael tries to hold his legup at theheight ofhis otherknee, Joebarelylishisfootoffthefloor).Thistests balance, which deteriorates with age and is usedhereas anindicatorofhow'old'someone
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is compared with the average fortheirage.The secondtest, theruler test, is fun andsimple - the two men hold their thumb and a finger slightly apart, with a ruler just above thegap. They then have to catch the ruler when it is dropped between their finger and thumb. At the age of 50 the ruler should be caught somewherearoundthefiveinchmark(theruler has the starng numbers at the top and the highestnumberontheruleratthe boom).Joe manages tograbit atthe four inchmarkand Michaelmanagedeight.Dotrytheseathome! The boys then go into Fontana's office to get their bloodtestresults.Fontana tells themthat Joe'sbodyfatis11.5%andMichael'sis27.1%. Looking at the full blood test results, Fontana thenstatescategorically "Joseph isn't goingto develop Cardio Vascular Disease (CVD). It's impossible to develop stroke, Myocardial infarconheartaack],heart failure."That'sa bit strong - "impossible" -really?! Mosley asks whatwouldhappento himifhe followedJoe's lifestyle. Fontana answers "In a year you are goingtobecured."Bitstrongagaininmyview. OfftotheUniversityofSouthernCaliforniaand Mosley meets Professor Valter Longo and a couple ofmice.One ofthemiceis quite special, as heholds the worldmouse longevity record. The bigmouse will live approximatelytwoyears and the smallerone about40%longer.The lile mouse is literally a fracon of the size of the 'normal'mouse -aboutonehalforone thirdof thevolume fromobservaon. Mosley narrated that thelilemouse has"incredibly lowlevels ofa growth hormonecalledInsulin-likeGrowth Factorand itseems IGF1is a keyfactorlinking calorierestriconwithlongevity." Mosley then introduces the extremely rare condion of Laron syndrome (suffered by approximately 300 people worldwide). Longo met some people in remote parts of Ecuador
withthecondionandtheyreach barely upto Longo's belly buon in height. People with Laron syndrome also have exceponally low levels ofIGF1 -hencethe impairedgrowth(as with lile mouse). They also seem to be "virtually immune"to diabetes and cancer. The programme actually doesn't menon longevity in relaon to these Ecuadorian villagers. The implicaon is clearly that the avoidance of major killers, such as diabetes and cancer, means that people with Laron syndrome live longer, but the programme doesn't claim this and otherevidence suggeststhatthis is not the case. "Unlike dwarfmice,however,people with Laron syndromedonotseemtoexperienceincreased longevity" is a statement from an arcle in whichLongowasinvolved10. Mosley's voiceover states: "Our bodies are constantly in 'go-go' mode. Our cells driven to divide byIGF1.Butwhen IGF 1levelsdropour cells shiinto a completelydifferentmode.The body slows producon of newcells and starts repairingexisngonesinstead.DNAdamageis morelikelyto getfixedand that's whythe mice and thevillagers are protectedfromage related diseases." Mosley connues: "It turns out that there's somethinginthe foodweeatthataffectshow much IGF1ourbodies produce.Thatsomething is protein. When we eat a lot of protein, our cells get lockedin 'go-go'mode." No evidence for protein being the precursor of IGF 1 is offeredbytheprogramme-thisissimplystated asfact. Mosley asks "So- howdoyoureduce yourIGF 1?""Studiesoncalorierestriconsuggestthat eanglesshelps butit's notenough.As well as cu[ng calories, you have to cut your protein
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intake."Again-noevidenceisofferedforthis asseron.
d ay . N ot e xa ct ly r ol e m od el n ut ri o na l behaviour.
Longo advises Mosley to try a 3.5 day fast, whichhe does(he actually hasa disgusng50 calorie cup-a-soup each day). Longo explains that even a 24 hour fast can reduce glucose levels andlevels ofIGF1.Mosley hadhis blood levels of IGF1 measured beforeand aer the fast. (Mosley had had his IGF 1 blood levels measured at 28 nanomoles/litre in the UK beforeleavingforAmerica).Thenormalhuman valueforIGF 1in America is approximately 215 ng/ml and Mosley is there or thereabouts before the fast. Aer the fast, Mosley's levels fall to approximately 115 ng/ml. (The UK/USA conversionfactorforIGF1is -to convertng/ml to nmol/L mulply by 0.131 and to convert nmol/Ltong/mldivideby0.131).
Mosley'sfinal desnaonwas Balmorewhere he metProfessor MarkMason attheNaonal Instute on Aging and another special mouse. The mouse is exploring a maze to try to rememberwherehe sawfood.Themice being studied are desned to develop Alzheimer's disease.Whenthese miceareputon a dietof feast days and fast days they live without obvious signsofAlzheimer's forsixmonths toa year longer than they would otherwise have done. Mosley likens this to humans ge[ng Alzheimer's atthe ageof80 ratherthan atthe ageof50.
Chicago is the next stop for Mosley and he meets Dr Krista Varady. Mosley has already decided that he doesn't ever want to do the fourdayfastagain.Varadyis studyingAlternate Day Fasng (ADF) with humans. Women have 400-500calorieseveryotherdayandmenhave 500-600 and the day in between the subjects are supposed to eat whatever they want. At about 39 minutes into theprogramme Varady bangs on about good and bad cholesterol, which loses the programme overall credibility. (Cholesterolischolesterol.Thereisnogoodor bad version. LDL and HDL are not even cholesterol-theyarelipoproteins). Varadyconcludedthatitdidn'tmaerifpeople had a lowfatora high fatdietonthe 'feed'day. The keything wasto have the very lowcalorie day. She also observed that, even though people had approximately 25% of normal calorie intake on the 'fast' day, they didn't compensate byhaving175%ofcalorie intake on the 'feed' day. Varady took Mosley to a drive through fast-food junk restaurant on the feed
When the mice eatwhatiswronglydescribedas a high fat diet they develop Alzheimer's much earlier.Masonsays"whenweputfructosein their drinkingwater,thathas a dramaceffect. The animals will have an earlier onset of the learning and memory problems - 3-4 months sooner."Mosleyequates thefructoseimpactto developingAlzheimer's in one's 30s or40's -not evenas late as the age of 50. Fructoseis, of course, sugar and zero fat content. Another commonerrorthatimpacts overall credibility of theprogramme. Mosley asks Mason what's going on. The brains of the fasng mouse showed that "sporadic bouts of hunger encourage new neurons to grow." The raonale is given by Mason in evoluonary terms that - if you're h un gr y, h av in g t he c og ni v e a bi li ty t o remember where you last saw food gives a survival advantage, so the fiest develop this and survive. I found this plausible but, as Masonhimselfsays,this needs tobe testedin humans. We cannot make assumpons from observaonsinmice.
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"Hunger really does make you sharper" says Mosley.He'sconvincedalready. Masonbelieves thatADF has beereffects on thebrainthana lower amountofdaily Calorie Restricon.This isbasedon his workwithmice and he again admits that this research now needstobeextendedtohumans. Mosley'sfinal experimentwas to trysomething recommended by Mason:five days ofnormal eang and two days at 600 calories a day. Mosley did this when hegotback tothe UK - aer firsthavinganotherIGF 1bloodtest.This one was even higher than his 28 nanomoles/ litre before he le for America. This suggests thatanybenefitofthe3.5dayfastdidnotlast. Aer five weeks on this 5/2 diet, Mosley had lost over a stone (measuring at 173.8lbs) and his body fat percentage had gone below 20%. IGF1haddroppedby50%.Mosleytalkedabout his reduconin total cholesterol and increase in 'good' cholesterol and his GP wife, of course, didn'tcorrecthim. That's the synopsis.Let's lookatthe logicofthe programmetoseewhatitmayormaynothave proven...
Logicoftheprogramme Q1) Has it been proven that lowering IGF 1 makeshumanslivelonger? No. The humans with Laron syndrome have "virtual immunity" from diabetes and cancer, butnoevidenceofdifferentlongevity.Noother human studywas referencedbytheprogramme (Iamnotawarethatoneexists)whereIGF1has been lowered in humans for a long enough period of me, against a comparator control group,tomeasurelongevity.
Q2) Has it been proven that Alternate Day F as n g ( AD F) r ed uc es h um an r is k o f Alzheimer's? No. Some mice have shown delayed cognive impairmentwithADFandacceleratedcognive impairmentwithfructoseintake.The impactof fructose needs to be isolatedfrom theimpact of ADF and the whole topic needs to be researchedinhumans. Q3)HasitbeenproventhattryingtolowerIGF 1, aer reaching normal growth maturity, increaseslongevityinhumans? N o. T ho se w it h L ar on s yn dr om e h av e substanally lower levels of IGF 1 from birth anddonotdeveloptoaveragehumanheight. Mice with severe Calorie Restricon post weaninghavesubstanallylowerlevels ofIGF1 anddonotdeveloptoaveragemousesize. Q4) Has it been proven that reducing protein intakereducesIGF1(notwithstandingthatthe programmehasnotprovenlongevityimpactof thisinhumans)? No. One subject (Mosley) fasted for 3.5 days and thus reduced calories, vitamins, minerals, carbohydrate, protein and fat simultaneously. Blood levels ofIGF1droppedinthisone subject at the endof the 3.5 day fast, as did glucose bloodlevels andas did probably bloodlevels of anymeasure. Q5) Has it beenproventhatfasng for a few daysreducesIGF1? In one subject in the short term, yes. In the same subject, in the medium/longer term, no (blood levels were above the original levels aerreturningtotheUK). Q6) Has it been proven that Alternate Day Fasng(ADF)impactsIGF1inhumans? No.Thiswasnottestedintheprogramme.
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Q7)HasitbeenproventhatCalorieRestricon everydayimpactsIGF1inhumans? No.Thiswasnottestedintheprogramme. Q8)Has itbeen proventhatfive days ofnormal eangfollowedbytwoverylowcaloriedaysa weekimpactsIGF1inhumans? Inonesubjectaerfiveweeks,yes. Whichtakes us backto:Q1)Has itbeenproven that loweringIGF 1makes humans livelonger? No. Myoverallconclusionthereforeis thatthis was aninteresngandenjoyableintroducontoa number of topics, but it proves virtually nothing.
Genes There's a topicI wantto briefly cover-someof youmay wish to do further research on this - andthat isthemenonof genecs early onin theprogramme. The ageofyourparents -especiallyyour same gender parent- can aidas a predictorof your longevity.Ourchildrenare likely tobe the first generaon that don't outlive their parents - a legacy of the obesity, diabetes, fake food, modern lifestyle.However, if youeat likeyour grandparents ate, you have a good chance of livinglongerthanyoursamegenderparent. Only three major studies have looked at the correlaon between longevity of parents and their children.The FraminghamStudywasone; The Longevity Study was another (also known as "Terman'sTermites"study) andtheAlameda CountyStudy.Ihave notreviewedthesestudies personally,butDrMichaelRoizenasks ifparent a nd o ffs pr in g l on ge vi ty c or re la t e a nd summarises thefindings asfollows inhis book TheRealAgeMakeover :
"Didthe twocorrelate?Yes,butminimally.Each study showed a minoreffect. TheFramingham Study, the most comprehensive of the three, found about a 6 percent correlaon between life span of the parents and life span of their offspring, meaning that many other factors affect longevity as well. If both your parents livedpasttheageofseventy-five,theoddsthat youwilllive pastseventy-fiveincrease tosome extent.Buttowhatextent? "Ifyouare a man andboth ofyourparents died beforethe ageof seventy-five, then yourReal Age (physiologic age) will be as much as 4.2 yearsolder.Ifyouareawoman,yourRealAge will be as much as 3.5 years older. If both parents livedpasttheage ofseventy-five,then your Real Age will be4.2 years younger ifyou are man, and 3.5 years younger if you are a woman. If no first-degree relave (parent, brother, sister) had breast, colon, or ovarian cancer diagnosed early, you are an addional 0.2toelevenyears youngerthanifyoursiblings or parents had those diagnoses. Some genec condions,such as beinga carrierofthe BRCA-1 breastcancergene,canmake your RealAge as much as 17 years older. This is one of the instances where genecs can make a big difference." I found this interesng, as I would have expected a stronger correlaon between life spanofparents and lifespanoftheir offspring. It just shows that lifestyle and environment remainsaveryimportantdeterminant. Let's now look at Calorie Restricon and I nt er mi e nt F as n g a wa y f ro m t he programme...
Background The work of the 1930s on Calorie Restricon precededandmay have inspired,someworkin
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the 1940s on IntermientFasng.A1945study called“Apparentprolongaonofthelifespanof ratsbyintermientfasng”byAntonJCarlson andFrederickHoelzel 11, references and builds uponMcCay's work.This arcle references one human experiment done by a man called Coronaro who lived from 1464 to 1566 and aributed his longevity to "rigid restricon of food intake."Carlson and Hoelzel recognisethat prolongedcalorie restriconis unlikelyto occur wh il e " su ffic ie nt p al at ab le f oo d i s ea si ly aainable". Thus they started to look at IntermientFasngas analternave to Calorie Restricon. They noted a study done in 1934 (Robertson, Ma rs to n a nd W al te rs " Th e i nfl uen ce o f i nt er mi e nt s t ar va o n a nd i nt e rm i e nt starvaon plus nucleicacid onthe growth and longevityofthe white mouse".)Inthis study,24 male and 24 female mice were fasted 2 successivedays in7(thisis interesng-it's the Mosley5/2).The averagelife span ofthefasted males was745 days while that of 24 controls was 712days (5% difference). Theaveragefor thefastedfemales was 819 days whilethat of 24 c ont ro l fe ma les w as 773 d ays (6 % difference). "The prolongaon of life was not regarded as significant by Robertson and his associates". The study reported that pepc erosion or ulceraon of the stomach and duodenumwas foundinsomemice (andyoung rats) aer single periods of starvaon of 36 hoursormore.Worthnong! Carlson and Hoelzel's own study improved in design by havingmicefrom the samelier in different study groups - a beer like-with-like comparison.Theirownstudycompared33rats allowed as much food as they wanted with groups of37,37and 30ratsthatwerefasted1 dayin 4,3and2,respecvely -fromthe ageof 42days.Theirresults showedthatthe apparent
life span was increased by the Intermient Fasng. The opmum interval for fasng appeared to be fasng 1 day in 3 and this increasedthelife spanofmales fromthe same lier about 20% and females from the same l i er a bo ut 1 5 %. H o we ve r, t he p re experimental condion of the individual rats was also found to be an important factor determiningthelifespans. The original work on Intermient Fasng and Calorie Restricon was therefore done from a longevityperspecve– can itmake animals live longer? Morerecentstudies arelookingatthe s am e i ss ue - l on ge vi ty . W e' ll t her ef or e concentrate on possible longevity benefits for now and look at possible benefits for weight lateroninthisarcle. A Calorie Restricon study has been done on the Rhesus monkey (startedin 1987)to usean animal closer to humans for a study subject. The studywas done bythe Naonal Instuteon Aging - one of the instuons visited by Mosley12. The monkeys were given a 30% calorie restricon. The interesng part of the conclusionformeis: "Wehave observedphysiological effects ofCR t hat paral lel rodent studies and may be predicveofanincreasedlifespan.Specifically, results from the NIAstudyhave demonstrated that CR decreases body weight and fat mass, improves glucoregulatory funcon, decreases bloodpressureandbloodlipids,anddecreases body temperature. Juvenile males exhibited delayed skeletal and sexual maturaon... Although81%ofthe monkeys inthe studyare sll alive,preliminary evidence suggests thatCR will have beneficial effects on morbidity and mortality." The studyis therefore observingimprovements in healthindicators and extrapolangtheseto
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predicted increased lifespan. Lower weight, decreased body temperature etc may extend life,butwedon'tasyetknowthisinprimates, let alone humans. Even if we find conclusive evidence-canhumans live in the modernworld day-aer-day consuming almost one third fewercaloriesthanweneed? Heilbronnand Ravussinreviewedthe literature av ai la bl e i n 2003 i n t he ar c le " Cal or ie restricon and aging: review of the literature and implicaonsforstudiesin humans."13 They concluded: "Calorie restricon(CR)extendslife span andretards age-relatedchronicdiseases in a variety of species, including rats, mice, fish, flies, worms, and yeast. The mechanism or mechanisms through which this occurs are unclear." The longest running scienfic study of CR in primates was begun at the University of Wisconsin in 1989. A recent publicaon from that study was called " Caloric restricon and aging: studies in mice and monkeys."14 As recently as 2009, study authors Anderson, Shanmuganayagam and Weindruch were sll s ta n g t ha t p os si bl e m ec ha ni sm s w er e unknown: "It is widely accepted that caloric restricon (CR) without malnutrion delays the onset of aging and extends lifespan in diverse animal models including yeast, worms, flies, and laboratoryrodents. The mechanismunderlying this phenomenon is sll unknown. We have hypothesized that a reprogramming of energy metabolismisakey eventin the mechanismof CR (That was Anderson and Weindruch's hypothesisin2007)..." I haveseenthis hypothesiselsewhere.The idea is that restricng food intake so substanally slows the animal's metabolism that this has direct benefit on longevity. Higamiet al. 2006
suggested that long term Calorie Restricon m ay d ow n r eg ul at e a pp ro xi ma te ly 5 0 inflammatory genes. This wouldbe a plausible andimportant pathway. Simpler explanaons are that thelower metabolism puts less strain onallsystems in the body-digesve,endocrine (hormones), circulatory, lymphac, immune systemand so on and that this alone enables thebodytofunconforlonger. The factremains thattherehas notyetbeena long-term,randomizedclinical trial ofCR orIFin humans,so wecannotknowwhetherornotCR or IF prolongs human life. I do not ancipate that such trials will be done involving Calorie Restricon, not least because I can’t think of many humans who could tolerate about one thirdof the foodintake thatthey needforany period of me. We have The Minnesota StarvaonExperiment15,butthis onlyinvolveda period of 24 weeks of calorie deprivaon – that’s not long term Calorie Restricon - and the outcomes for general well being in this importantstudywerenotgood. Some groups ofChrisans, Buddhists,or other people who eat relavely lile for religious reasons,maybetheclosestthatwecangetto observing prolonged periods of fasng or Calorie Restricon and the effect on humans. Anecdotally, we do see elderly monks and elders of communies (evidence of longevity), but this has not been quanfied in research, standardised against other comparator groups and there are so manyotherfactors to take into account with these groups of people that this cannotbe viewedas scienfic.Notleastthelack ofstress andhavingno mobile/ipad and email in such communies probably adds years to one’slife. Researchers at the Intermountain Medical Center inUtah reportedin2007andApril 2011 that fasng, (not eang and drinking only
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water), for24 hours may be linkedto a lower risk of heart disease and diabetes. The most recentstudywaspublishedinApril201116.The study was done overone 24hourperiod!In the s ec on d ( 20 11) s tu dy , t he s ub je ct s w er e monitored for another 24 hours as they returned to normal eang. Blood tests were takenand itwas found thattriglycerides,weight and blood glucose levels dropped during the fast - no surprise there. This was then extrapolated to conclude that a) this would connueifthisexperimentwererepeated(not eang for 24 hours) and b) that this would loweroverall riskofheartdisease anddiabetes. The 2011 study interesngly found that, as triglycerides fell so LDL andHDL increased(by 14%and6%respecvely)andtotalcholesterol increased. I don'tcare about bloodcholesterol levels,butnodoubtpeoplemeasuringthemdo. Human Growth Hormone also increased interesnginthecontextofIGF1above. Icanseesomelogicforanumberofwaysin which Intermient Fasng and/or Calorie Restriconcouldhavehealthbenefits: 1) Weknow thathighlevels of glucose in the bloodare dangerous –GaryTaubesandRobert Lusg even use the term “toxic”. The less we dumplots ofglucose into ourbloodstream,and theless oenwe do this,the beerthis has to be.I oenthink ofType 2Diabetes as the body saying“enough’s enough –I can’tcope withthis glucose/release insulin/get the balance just rightkindofchallengeanylonger–I’mpacking up.”Italso follows thatbynot over-workingthis mechanism, we will achieve benefits for our health. 2) Theliver,kidneys andheartgenerally willbe less taxed by someone eang less and/or less oen.They have lessto do andcan,arguably, perform other funcons more freely without havingto dealwithfoodall the me.(The liver
has approximately 500 funcons to perform within the body. I can see how it would appreciate a day off from metabolising food everynowandagain.) ) There is clearly an evoluonary argument that wewould not havebeen ableto eat the amountoffoodthatwe cananddo today and hence we have not evolved to eat with the regularity and quanty that we currently do. Oureangpaernwouldmoreaccuratelyhave beencalledIntermientEangin the past-the fasng would have been the status quo parcularlysoduringtheleanwinterperiods. 4) Muchemphasisis placedin literature onIF or CR that the food consumed must be highly nutrious to compensate for the reduced intake. Thisalone may havesome benefit.The CRperson whomMosleymet- Joseph- would be most unlikely to consume empty (sugar/ flour) calories and therefore another health benefitpathwaycouldbethatpeoplewhoeat less may eat beer. This does need to be measured against any loss of nutrients from reduced food intake. I have not seen any menonof this inthe IF/CRliterature,letalone a study thereof. If humans are following the Chicago/Dr Varady Alternate Day Fasng and havingburgers and chips onthe 'feed'dayand 600low fat/high carbohydrate calories on the 'fast' day, they will highly likely miss out on essenal fats, protein, vitamins and minerals. Therewill behealth consequencesof this that needtobefactoredin.
If someone wants to try CR or IF, I would recommendIFoverCR.LikeCarlsonandHoelzel from the 1940s, I don't think that prolonged Calorie Restricon is widely achievable while "sufficientpalatablefoodis easilyaainable".I also worry that CR is so similar to The Minnesota StarvaonExperiment thatI cannot see how a differentoutcomewouldensue.With
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CR, I would ancipate hunger, food obsession and anymodernhuman, livingfreely,woulddo whatthe Minnesotamenwouldhavedonehad they not been ‘imprisoned’ – eat, overeat and regain any lost weight andmore andlose any possiblehealthbenefits.
be loved; getenough sleepand have something thatgivesyourlifemeaningandpurpose.
Ifyou want to do IFbecause youthink it will makeyoulivelonger,Ihavethreethoughtsfor youtoconsider:
Just before we move on, in July 2012 I came a cro ss very in teres ng UK d at a f or li fe expectancyandhealthylifeexpectancy17:
1) There has not yet been a long-term, randomized clinical trialof CR or IFin humans, sowecannotyetknowwhetherornotCRorIF prolongshumanlife; 2) Any benefitsobservedin animals have been fromsucha youngage thatgrowth overall has beenstunted.a)I assume thatyouwouldrather be Arnie Schwarzenegger than Bob Hoskins in stature (although,interesngly,you mayfavour Kylie over Brigie Nielsen) and b) we do not know how much of the observed longevity is connected to the growth impairment. Either way-ifrodents have been observedto 'enjoy'a 5 -3 0% i nc re as ed l if e e xp ec ta nc y h av in g undergone CR or IF from post weaning, don't extrapolate this to you being fully grown and maybe in your 30s, 40s or even 70s and think that you can enjoy any such measurable extensioninlifeexpectancy. ) There are many other ways in which it is suggested that humans can enjoy a healthier life for longer, if not live longer. I would recommend that people achieve all of these beforestarngtocutbackonfoodintake-not leastwith the nutrional impactunexplored,let aloneknown.Thewidelyacceptedhealthgoals are:don'tsmoke;don'tdrinkexcessively;don't eat junk food; avoid trans fats; minimise exposure to chemicals and polluon; minimise stress;keep themind andbodyacve;love and
Notonlydo we needevidenceforanybenefitof CRand/orIF,ideallywewouldhaveanybenefit weighedupagainsttheseotherhealthmarkers sothatwecouldprioriseourgoals.
England Scotland Wales 2008-2010 averagelife expectancy 2007-2009 averagehealthy lifeexpectancy
Men
78.6
75.9
77.6
Women 82.6
80.4
81.8
Men
63.5
60.1
62.5
Women 65.5
63.5
62.8
The mostfascinang numbers ofall wereeven more regional than this - as thereport noted: "There was also considerable variaon in life expectancyat birthacross the English regions. Average life expectancy, formen and women, was highest in the South East (79.7 and 83.5 years respecvely) and lowest in the North West (77.0and 81.1years). At localarealevel across theUK, average lifeexpectancy at birth varied by 13.5 years for men (85.1 years in Kensington and Chelsea in London compared with 71.6 years in Glasgow City) and by 11.8 years for women (89.8 years compared with 78.0yearsforthesameareas)." IfyouwereborninKensingtonandChelsea,you have an incredible 13.5 years and 11.8 years advantage over your Glaswegian male and female comparatorsrespecvely. This reminds us that poverty and locaon also have a significant bearing on longevity and years of good health.So forgetstarvingand make sure thatyou'refemaleandborninaposhplace!
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Intermi3entFas7ng& WeightLoss Some of youmay beinterestedin starving for therestofyour life,totry toextendyourme on this planet by some unknown and immeasurable period of me, but, working in thefieldofobesity as I do,manyofus are just as,orevenmore,interestedinweightloss... HavingreadKeys'BiologyofHumanStarvaon (The Minnesota Starvaon Experiment),18 I'm notgoingtodiscussCalorieRestriconatallin this secon on weight loss. I have only seen evidence that even short to medium term aempts, let alone long term efforts, to connually create a calorie deficit result in weight gain to and then beyond the original starngweight.Thephysicalandpsychological effects ofsustained calorie deprivaon are well documented in this invaluable study: fague; hunger; depression; muscle wasng; hair loss; cognive impairment; inability to concentrate orfuncon;loss ofsexual desire;obsession;loss ofperspecve and so on.This is nota scenario anyone should consider embracing without readingthisgreatandcomprehensivestudy. Intermient Fasng may,however,have some benefitforthosetryingtoloseweight... Unlessyouareraidingthefridgeinthemiddle ofthe night, youarealreadyfasng while you are asleep. My husband, Andy, and I tend to have dinner around 6pm and have usually finished eang for the day on most days by 7pm.Occasionallywe'll havesome berries and/ or yoghurt aer the dog walk, at around 9.30pm, but we oen go from 7pm to 7am (aer the first dog walk of the day) without food. We aretherefore fasng for 12 hours a day, but wedon’t think of it asa fast – or a hardship–it’sjustbedme.
Michael Eadeshasdone an interesngblogon Intermient Fasng19 where he and his wife Mary have trialledfasng for24 hour periods. DrEades describes howthey seledona 6pm cut-off me sothat they didn’t eat from6pm one day to6pmthe next and thismeant that they could eat up to 6pm one day and aer 6pm on another day – thus never having a whole daywhen theyate nothing.This is a good ideaifyouwanttotrya24hourno-foodfast. DrEades makes references toratstudies where Intermient Fasng was taken to mean not eangonone dayand eangfreelyonthe next - i.e. Alternate Day Fasng. Eades states that the rats made up for the starvaon on the eang days, taking in a similar number of calories in total. I could not find evidence for such calorie 'restoraon' in literature that I reviewed. Thereis lilemenon inthis blogof anyimpact on weight experienced by the Eades. Theone relevant sentence says: “Over the period that we followed the various Intermient Fasng regimens we losta lile weightbecause,unlike the rodents, we couldn’t eat twice as much duringthe eangdays aswe wouldhave eaten werewenotfasng.” Mark Sisson also did a blog on Intermient Fasng20 and menoned his gym buddy, Syd, whofasts every Tuesday –he doesn’teataer d in ne r o n M on da y u n l b re ak fa st o n Wednesday. Art De Vany also recommends IntermientFasnganditisregularlydiscussed on Paleo forums,but,thereis lile in the wayof hard andfastrules and results.Youwon’tfind a “do this and this oen and this will happen.” This is onlytobeexpected –there is noformula forweightloss, full stop, sothere canbe none forthis‘tool’ inthe weight loss tool kit. Itwill sadlyhavetobesomethingthatsomeonetries forthemselvesandseesifitmakesadifference.
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Later in the same Dr.s Eades blog there is an interesngreference to a studypublishedin the MedicalHypothesis Journal inMarch 2006. Dr Laub experimented with an Intermient Fast whereby he and two colleagues ate whatever they wanted on non-fast days and consumed about 20-50% of their esmated daily energy requirements on the fasng days. Dr Eades notes themany health benefits,butthereis no menon of any impact on weight. How frustrang! Dr Laub refers to a 1957 paper where subjects were alternang between 900 and 2,300calories– averaging1,600calories – and maintaining weight. The subjects were elderly (in a residence for old people) and, again, many and various health benefits were noted, but only that weight was maintained. ThosetryingIntermientFasngforweightloss willwanttolose,notmaintain,weighthavingto starveeveryotherday.
intakeby about3,500calories to lose1lb offat, that means I’d lost just over 2lb of flab." He shouldhave made the conneconthatJoe,with his daily deficitof anywherebetween 200 and 700calories a day,should be losing between21 and 73lbs in fat alone each and every year (more ontopintermsofwaterand lean ssue). Given thatJoe has been doingthis fora decade, he should have been dead years ago! I share this point in theweight loss secon toremind people that the calorie formula is completely lackinginevidence22. 2) IntermientFasngOpon1:Afourdayfast, which is advised to be done every couple of months. This is what Mosley did and doesn't wanttodoagain-Idon'tblamehim.
CalorieRestric7on& Intermi3entFas7ngop7ons
) Intermient Fasng Opon 2: The Chicago team were looking at ADF - Alternate Day Fasng. The idea of this is that women have 400-500 calories a day and men 500-600 calories a day on the fasng day and you eat whatever you want on the 'feed' day. This sounds worryingly like binge/starve syndrome tome,otherwiseknownasbulimia.
There were four opons presented in the Horizonprogramme -oneforCalorieRestricon and three Intermient Fasng opons. These areagoodplacetostart:
4) IntermientFasngOpon3:The 5/2system - 5 normaldays eangand2 low calorie days with approximately600calories a day.This was theoponmostfavouredbyMosley.
1) CalorieRestriconwas whatJoewas doingin the Horizon programme - living on 1,900 caloriesa day. IfJoeweresedentary hewould have a deficit of approximately 200 calories a d ay, i f m od era tel y a c ve i t w ou ld b e approximately 400calories a dayandthedeficit would be approximately 700 calories a day if Joe is acve.Ina recentarcle21Mosleypledges his allegiance to the 3,500 calorie formula. Referring to his 3.5 days fast hesays: "At the end, I had missedout on about 7,500calories worthofmeals.Sinceyouneedtocutyourfood
Weightloss-backtobasics Whatwe wantto doistoachieveanypossible benefitsof Intermient Fasng without having to go to extremes. Let’s go back to basics, therefore,andthinkaboutwhatwe’retryingto achieve. We are trying to lose weight. This means that we are trying to break down triglyceride. We know that there are two circumstances inwhich this canbe done –the braincandemandthe glycerol (glucose)partof triglyceride for fuel and/or the body can
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demand the fatpartofthe triglycerideforfuel. We also know that breaking down triglyceride can(toall intentsand purposes) only bedone when there is insufficient glucose or glycogen available. If glucose is available, the brainand body will both use this preferenally for fuel. Hence,onThe HarcombeDiet®23,we runonlow glucose levels all the meandwedon’tgraze all day long, so that we have decent periods of me eachdaywhen ourbodycan burn ourown bodyfat. The well worn platude "eat less/do more" seems to havesome logic–surelyifwe justeat less the bodyhas to burnbodyfat.The body,of course, cananddoes adjust andus eang less willmostlikelyjustleadtothebodydoingless acvity and/or less basal metabolic acvity so that the eang less is just absorbed in doing less.We needtomake a demandonthebody’s need for fuel somehow, without thebody just doingless and/ortryingto getus to eatmore to compensate. So, wearetrying toget the body toburn fat. Theraonale would be– it’s one thing togive the body no reason not to burn fat – it’s anothertotrytoencourageittodoso.Note– not force, but encourage. We should always hold true the principle that we need to work with our body and never against it. It makes sense that our body will funcon beer if we can encourage our fat storing and fat burning mechanismto work well both ways. Clearly, in anyonewitha weight problem. thefat storing mechanism has been working well! The fat burningprocess has notbeenworkingsowell– especiallyif we have beencounngcalories and eangmorecarbohydrates. Thisis whereIntermientFasng may be able to deliver the biggest weight loss benefits, se[ng any health benefits aside for now. Havingthiskeymechanismworkingopmallyin
both direconscanonlybebeneficial forweight loss.Themorewecanencouragefatburningto occur, the more natural it should become for thebody.Wehavenoevidenceforthis,butthe logicissurelyclear. Thisis the thinkingbehindIntermientFasng and it has evoluon on its side. Remember MarkSisson’scharacter Grok? TheGrokfamily is usedin Primal Blueprint 24 todepict thecave family and how they wouldhave lived.The Grok family wouldundoubtedly have skipped meals andhadto go without food formanyandlong periods ofme.Ifglycogenis available the body will use this for energy. Ifit isn’t, the body is likely to make the person do less to compensate, but it can also draw on fat reserves if necessary. Grok’s body would have beenwelltunedtostoringand burningfat–his s ur vi va l d ep en de d o n i t. T he s ig ni fic an t difference between modern man and Grok is thatGrok had nochoice butto gowithoutfood forperiods ofme.Itis toughnottobeableto find fo od, but arguably toug her to be surroundedby foodandtohave to consciously not eat.
Howtofastintermi3ently Therearefive key thingsto thinkabout before you try Intermient Fasng in the context of tryingtoloseweight: 1)Ifitain’tbroke,don’tfixit.
Ifyou are currentlydoingwell withyourweight loss–sckwithwhatyou’redoing–don’tplay around with things like Intermient Fasng unlessyouneedto. 2) Youmusthavearegularbasefromwhichto start.
Itis crical thatyouhavehada periodofme w he re y ou e at r eg ul ar ly b ef or e t ry in g
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Intermient Fasng. The body needs to be in the state where itknows itgets regularhealthy fuelandbeworkingwithyoubeforeyoustart playingwiththerules. OnTheHarcombeDiet ®22,we makea point of ge[ngyouinto the habitofthree regularmeals a dayfora periodofme. Weoenquote the rule of thumb that it takes approximately 21 daystoformanewhabit,soweneedtoeat three regularmeals a dayforatleastthis length of me and ideally longer for your body to realisethat youareno longer calorie counng or bingeing and starving – you are regularly nourishingyourbodyandwithoutfail. At this point, your body is going to be fine missing the odd meal. Don’t miss a meal regularly – or thebody will adjust to thenew paern –butthe oddonehereorthereand the body won’t think you’ve gone back on some dadiet.Itmayslowyoudown a bit,butitwill justas likely use fatreserves–andthat’s what wewantittodo. ) You must have stable blood glucose levels beforeyoufast.
It is crical that your blood glucose level is stable beforetrying IntermientFasng.If you findthata porridge breakfastleaves youhungry latemorning,then thisis notthe idealmeal to havebeforetryingto skip a meal.Ifyouhavea carb breakfast and then decide to skip lunch, you may well have a blood glucose high very soon aer the porridge and then a blood glucose lowabout90-120minutes aer.Evena slight high and low may make your blood g lu co se l ev el i ns uffi ci en tl y s ta bl e t o t ry IntermientFasng.Skippingamealwhenyour blood glucose level is lowis nothealthyorlikely tobeachievable.You are likelytobe ina state oflow bloodglucose (hypoglycaemia)and your body willbecryingoutforfood.Youwill getall
the body’s symptoms of hypoglycaemia as it triestogetyoutoeat–shakyhands,irritability, can’t concentrate, thinking about food all the me,headaches,lightheaded feeling and soon. You have a low chanceof being ableto resist thisonslaughtfromthebody. As long as you skip a meal when your blood sugar is stable (e.g.miss lunchaer a saang egg and real bacon breakfast), there is no reason for you to have a hypoglycaemic episode. Do watch out for hungerearlier than normal fordinnerand make sure thatyou don’t get so hungry that youstarteang thewrong thingsbeforeyourhealthydinner. 4) Itis important not tomakethis regular,or thebodywilljustadjust.
If you always miss breakfast, the body just doesn’t kick start your metabolismfor theday unlyou break your overnight fast(that’s why it’s called break-fast). Intermient Fasng will workbestif/whenit happens naturally–ifyou trytoplan ityoumay makeitregular,you may compensate in advance if you think you are goingtomissameal.Ifyoufindyouhavebeen sobusythat it’s 2pmand you haven’thadlunch andyou don’t feel hungry(becauseyou hada greatbreakfast)– go withit andhave anearly and good dinner and you should have been burningfatduringtheday. Ifyou’re latehomefrom workandred– just go to bed early and don’t have a disturbed night’s sleep by eang too late and having to digestfoodwhileyou’retryingtosleep. 5) Itis importantto approach this with theright mindset.
This is why natural ‘it just happened’ meal skipping has got to be beer than planned missed meals. There will be a tendency to
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compensate in advanceandinretrospect ifthe missedmealismoreplanned. Intermient Fasng needs to come with a posive mindset– nota deprivedmindset.You needtobe thinking–this is a greatopportunity to encouragesome fat burning, not thinking – I’mgoingtobe hungryandfeel likeI’vemissed out. Ifyoufindthatyouareeangso muchmoreat other meals, just because you missed one, or you find that this starts reawakening an unhealthypreoccupaonwithfood,then thisis nothealthyforyou.Ifyou findthatitmakes you feel mentally alert and that you enjoy the occasionalfeelingofhungerandtheenhanced enjoymentof themeal thatfollows, this could beanewtoolinyourkitbag. If you want to try Intermient Fasng, I recommendskippingmeals,asandwhenitcan naturally be done andwhenyourblood glucose levels are stable and if you have the right mental approach to it and not in other circumstances.As a suggesonforhow oen– ifyouneedsomethingtokickstartyourweight loss, you may benefit from naturally skipping one or two meals a week. It’s another opportunitytogetyourbodytoburnfat.
Conclusions The studies into Intermient Fasng to date have been much more about health benefits than weight loss (and indeed the Calorie Re st ri c on s tu di es s ee m t o h av e b ee n exclusivelyfocused on health benefits).The fact remains that there has not yet been a longterm, randomized clinical trial of CR or IF in humans,so wecannotknowwhetherornotCR orIFprolongs human life (orachieves sustained weightloss).
Studies on animals have beenencouraging,but with thestrongcaveats thata)the experiments were started very young and growth was substanally impaired; b) the animals were containedandnotsubjecttothetemptaonsof 'free range' humans and c) themechanism by which any benefits may be occurring is not known. The Horizon programme suggested that IGF 1 may be thekeyfactorandthatprotein inturn may be the key determinant of IGF 1. The programmeprovedneither. We have suggested a number of plausible benefit pathways in this arcle: less strain on the systems of the body; reduced and/or less frequent consumpon of glucose/fructose (althoughthis canbeachievedwithoutfasng); beeraenonpaidtooverallnutrionwhile eanglessatmesetc. The Minnesota Experiment tells us thatCalorie Restricon-anapproximate30%caloriedeficit over a long period of me - is likely to have d e le t er i o u s e ff ec t s o n p h ys i ca l a n d p sy ch ol og ic al w el l b ei ng . I c ou ld n ot recommendthis personally. Joein the Horizon programmeand Victoria Beckhamappearto be rarebeingsinmanagingthis! T he re i s n o c on cl us iv e e vi de nc e t ha t Intermient Fasng has beenshownto havea sustained benefit for weight loss. However, thereis alogicthat encouraging thebody's fat burning mechanismto do its work will have a benefit. There may be other benefits, such as people feeling more inclined to eat beer overall when they are pu[ng quite a bit of effortintoaformofIFonoccasions. There areno set rules for Intermient Fasng and no agreementontheopmal opon.There is some logic that 5/2 will be easier (and therefore more likely to be adhered to) than
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AlternateDay Fasng.Fasngfor a fewdays at a me seems to be generally regarded as challenging,tosaythe least,bythosewhotryit. The opon chosen by the Eades and Mark Sisson's gymbuddy seems a good onefor a 24 hourfast- start aer dinner oneday andthen there isno whole daywhenno meal is eaten. The threevariables to considerforIntermient Fasngare: 1) How much food - none vs. approximately 500-600caloriesaday; 2) Howlongthis is donefor-days vs.24hours; and ) Howoen this isrepeated- everyotherday oralongerfasteveryfewmonths.
As with any newopon,you may like togeta pieceofpaperandwritedown the benefits on one side and the costs ontheother - for you personally and no oneelse. Benefits might be "I'll take the chance that this may benefit longevity" or "I quite like the discipline of skipping a couple of meals every now and again." Costs might be "I'm worried I'll start obsessing about food again" or "I may lose a daywhenIfast,asIcan'timagineworkingon anemptystomach."
the same way that type 2 diabetes is glucose intolerance for the body. Indeed, on the day thatIwaswringtheconclusionforthisarcle, the headlinesworldwidewere "Loseweight to beatdemena"25and"Obesity'badforbrain'by hastening cognive decline."26 Is there any plausible mechanism by which being obese or overweight per se can cause demena or cognive decline? I can't think of one. I can, however, think of how the incessant and substanal consumpon of carbohydrate/ glucose, when we have not evolved to eat in this way, cancause obesity and mental harm. So,whetheror not youIntermiently Fast,for opmal health keep sugars and things that breakdownintosugarsubstanallycurtailed,if notoutofyourlifealtogether. I hope that you've enjoyed this exploraon of Calorie Restricon, Intermient Fasng, health and weight loss. Well done Mr Mosley for ge[ng us thinking - that will keep the mind workingandhopefullyAlzheimer'satbay! ZoëHarcombe August2012
Ifthe costs outweigh the benefits,thinktwice.If the benefits outweigh the costs,the final step in theprocess is to see if theperceived benefits canbeobtainedviaanalternaveroute.Ifyou like the ideathat this may delay the onset of cognive decline (and who wouldn't)- canyou do mo re p uzz les ? l ea rn s om et hi ng n ew regularly?debate witha good'sparringpartner' whokeepsyouonyourtoes? That's justmindworks outs. For physicalthings thatyoucando-rememberthatAlzheimer'sis starngto be calledtype 3diabetes.It appears tobeglucoseintolerance for the braininmuch
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References. 1]
hp://www.bbc.co.uk/programmes/b01lxyzc
2]
hp://www.youtube.com/watch? v=Pfna7nV7WaM 3]
hp://www.youtube.com/watch? v=tyQSzx0oo 4] hp://www.zoeharcombe.com/2009/05/10things-you-should-know-about-losingweight-27-5-09/ 5]
hp://www.bbc.co.uk/programmes/ p00wzn5j 6]
hp://www.lef.org/magazine/ mag95/95dec2h.htm
ToddTucker,TheGreatStarvaConExperiment , publishedbySimon&Schuster,(2006). 16]
hp://www.eurekalert.org/pub_releases/ 2011-04/imc-sfr033111.php 17]
hp://www.nao.org.uk/publicaons/1213/ healthcare_across_the_uk.aspx 18]
AncelKeys,TheBiologyofHuman StarvaCon,MinnesotaUniversityPress,(1950). 19]
hp://www.proteinpower.com/drmike/ intermient-fasng/fast-way-to-beer-health/ 20]
hp://www.marksdailyapple.com/fasng/
21] 7]
hp://www.zoeharcombe.com/assets/ downloads/Farmers_Factsheet_3Nutrients_in _foods.pdf
hp://www.dailymail.co.uk/health/ arcle-2183677/Why-starvaon-diet-actuallygood--make-live-longer.html 22]
8]
hp://www.cnpp.usda.gov/Publicaons/ DietaryGuidelines/2010/PolicyDoc/ PolicyDoc.pdf (page14)
ZoëHarcombe,TheObesityEpidemic:What causedit?Howcanwestopit? Columbus Publishing(2010) 23]
9]
hp://www.ncbi.nlm.nih.gov/pmc/arcles/ PMC2946087/ 10]
hp://www.scienficamerican.com/ arcle.cfm?id=defecve-growth-gene-indwarfism
ZoëHarcombe,StopounCngalories& StartLosingWeight:TheHarcombeDiet . ColumbusPublishing(2008) 24]
hp://primalblueprint.com/products/ThePrimal-Blueprint.html 25]
11]
hp://jn.nutrion.org/content/ 31/3/363.short
hp://www.express.co.uk/posts/view/ 340955/Lose-weight-to-beat-demena 26]
12]
hp://www.ncbi.nlm.nih.gov/pubmed/ 12543259
hp://www.bbc.co.uk/news/ health-19323061
13]
hp://www.ncbi.nlm.nih.gov/pubmed/ 12936916 14]
hp://www.ncbi.nlm.nih.gov/pubmed/ 19075044 15]
hp://www.zoeharcombe.com/2009/12/ the-minnesota-starvaon-experiment/ AncelKeys,TheBiologyofHumanStarvaCon, MinnesotaUniversityPress,(1950).
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AbouttheAuthor ZoëHarcombeisanauthor,researcher,speaker andfounderofTheHarcombeDiet®.Shehas5 bookspublished: ‘Whydoyouovereat?Whenallyouwantisto beslim’;‘StopounCngalories&StartLosing weight:TheHarcombeDiet’;TheHarcombeDiet RecipeBook’;‘TheObesityEpidemic.What ausedit,Howcanwestopit?’and‘The HarcombeDietforMen:NomoreMrFatguy!’. Allherbooksandfurtherinformaonabouther workareavailableatZoeHarcombe.com.
AboutTheHarcombeDiet ® PROPlan TheHarcombeDiet®PROPlanisadietand nutrionsupportprogramforhealthandfitness professionalstousealongsidetheircurrent clientacvies.Itlicencesmemberstooperate asaffiliatesofTheHarcombeDiet®andtouse thisassociaoncommerciallyaspartofyour business.Membershipfeesareextremely compeveandyouwillalsoreceiveweekly digests,specialreports,diet&healthpsand fullaccesstoTheHarcombeDietClub.comwitha specialmembersforum. Pleasefindmoreinformaonat theharcombedietclub.com/proplan.
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