Bad Science

Dr Gillian McKeith PhD

I’m going to push the boat out here, and suggest that since you’ve bought this book you may already be harbouring some suspicions about multi-millionaire pill entrepreneur and clinical nutritionist Gillian McKeith (or, to give her full medical title: Gillian McKeith).

She is an empire, a prime-time TV celebrity, a best-selling author. She has her own range of foods and mysterious powders, she has pills to give you an erection, and her face is in every health food store in the country. Scottish Conservative politicians want her to advise the government. The Soil Association gave her a prize for educating the public. But to anyone who knows even the slightest bit about science, she is a joke.

The most important thing to recognise is that there is nothing new here. Although the contemporary nutritionism movement likes to present itself as a thoroughly modern and evidence-based enterprise, the food-guru industry, with its outlandish promises, moralising and sexual obsessions, goes back at least two centuries.

Like our modern food gurus, the historical figures of nutritionism were mostly enthusiastic lay people, and they all claimed to understand nutritional science, evidence and medicine better than the scientists and doctors of their era. The advice and the products may have shifted with prevailing religious and moral notions, but they have always played to the market, be it puritan or liberal, New Age or Christian.

Graham crackers are a digestive biscuit invented in the nineteenth century by Sylvester Graham, the first great advocate of vegetarianism and nutritionism as we would know it, and proprietor of the world’s first health food shop. Like his descendants today, Graham mixed up sensible notions – such as cutting down on cigarettes and alcohol – with some other, rather more esoteric, ideas which he concocted for himself. He warned that ketchup and mustard, for example, can cause ‘insanity’.

I’ve got no great beef with the organic food movement (even if its claims are a little unrealistic), but it’s still interesting to note that Graham’s health food store – in 1837 – heavily promoted its food as being grown according to ‘physiological principles’ on ‘virgin unvitiated soil’. By the retro-fetishism of the time, this was soil which had not been ‘subjected’ to ‘over-stimulation’ … by manure.

Soon these food marketing techniques were picked up by more overtly puritanical religious zealots like John Harvey Kellogg, the man behind the cornflake. Kellogg was a natural healer, anti-masturbation campaigner, and health food advocate, promoting his granola bars as the route to abstinence, temperance and solid morals. He ran a sanatorium for private clients, using ‘holistic’ techniques, including Gillian McKeith’s favourite, colonic irrigation.

Kellogg was also a keen anti-masturbation campaigner. He advocated exposing the tissue on the end of the penis, so that it smarted with friction during acts of self-pollution (and you do have to wonder about the motives of anyone who thinks the problem through in that much detail). Here is a particularly enjoyable passage from his Treatment for Self-Abuse and its Effects (1888), in which Kellogg outlines his views on circumcision:

The operation should be performed by a surgeon without administering an anesthetic, as the brief pain attending the operation will have a salutary effect upon the mind, especially if it be connected with the idea of punishment. In females, the author has found the application of pure carbolic acid to the clitoris an excellent means of allaying the abnormal excitement.

By the early twentieth century a man called Bernard Macfadden had updated the nutritionism model for contemporary moral values, and so became the most commercially successful health guru of his time. He changed his Christian name from Bernard to Bernarr, because it sounded more like the roar of a lion (this is completely true), and ran a successful magazine called Physical Culture, featuring beautiful bodies doing healthy things. The pseudoscience and the posturing were the same, but he used liberal sexuality to his advantage, selling his granola bars as a food that would promote a muscular, thrusting, lustful lifestyle in that decadent rush that flooded the populations of the West between the wars.

More recently there was Dudley J. LeBlanc, a Louisiana Senator and the man behind Hadacol (‘I had’da call it something’). It cured everything, cost $100 a year for the recommended dose, and to Dudley’s open amazement, it sold in millions. ‘They came in to buy Hadacol,’ said one pharmacist, ‘when they didn’t have money to buy food. They had holes in their shoes and they paid $3.50 for a bottle of Hadacol.’

LeBlanc made no medicinal claims, but pushed customer testimonials to an eager media. He appointed a medical director who had been convicted in California of practising medicine with no licence and no medical degree. A diabetic patient almost died when she gave up insulin to treat herself with Hadacol, but nobody cared. ‘It’s a craze. It’s a culture. It’s a political movement,’ said Newsweek.

It’s easy to underestimate the phenomenal and enduring commercial appeal of these kinds of products and claims throughout history. By 1950 Hadacol’s sales were over $20 million, with an advertising spend of $1 million a month, in 700 daily papers and on 528 radio stations. LeBlanc took a travelling medicine show of 130 vehicles on a tour of 3,800 miles through the South. Entry was paid in Hadacol bottle tops, and the shows starred Groucho and Chico Marx, Mickey Rooney, Judy Garland, and educational exhibitions of scantily clad women illustrating ‘the history of the bathing suit’. Dixieland bands played songs like ‘Hadacol Boogie’ and ‘Who Put the Pep in Grandma?’.

The Senator used Hadacol’s success to drive his political career, and his competitors, the Longs – descended from the Democrat reformer Huey Long – panicked, launching their own patent medicine called ‘Vita-Long’. By 1951 LeBlanc was spending more in advertising that he was making in sales, and in February of that year, shortly after he sold the company – and shortly before it folded – he appeared on the TV show You Bet Your Life with his old friend Groucho Marx. ‘Hadacol,’ said Groucho, ‘what’s that good for?’ ‘Well,’ said LeBlanc, ‘it was good for about five and a half million dollars for me last year.’

The point I am making is that there is nothing new under the sun. There have always been health gurus selling magic potions. But I am not a consumer journalist, and I don’t care if people have unusual qualifications, or sell silly substances. McKeith is, for me, very simply a menace to the public understanding of science. She has a mainstream prime-time television nutrition show, yet she seems to misunderstand not nuances, but the most basic aspects of biology, things that a schoolchild could put her straight on.

I first noticed Dr Gillian McKeith when a reader sent in a clipping from the Radio Times about her first series on Channel 4. McKeith was styled, very strikingly, as a white-coated academic and scientific authority on nutrition, a ‘clinical nutritionist’, posing in laboratories, surrounded by test tubes, and talking about diagnoses and molecules. She was also quoted here saying something a fourteen-year-old doing GCSE biology could easily have identified as pure nonsense: recommending spinach, and the darker leaves on plants, because they contain more chlorophyll. According to McKeith these are ‘high in oxygen’ and will ‘really oxygenate your blood’. This same claim is repeated all over her books.

Forgive me for patronising, but before we go on you may need a little refresher on the miracle of photosynthesis. Chlorophyll is a small green molecule which is found in chloroplasts, the miniature factories in plant cells that take the energy from sunlight and use it to convert carbon dioxide and water into sugar and oxygen. Using this process, called photosynthesis, plants store the energy from sunlight in the form of sugar (high in calories, as you know), and they can then use this sugar energy to make everything else they need: like protein, and fibre, and flowers, and corn on the cob, and bark, and leaves, and amazing traps that eat flies, and cures for cancer, and tomatoes, and wispy dandelions, and conkers, and chillies, and all the other amazing things that the plant world has going on.

Meanwhile, you breathe in the oxygen that the plants give off during this process – essentially as a byproduct of their sugar manufacturing – and you also eat the plants, or you eat animals that eat the plants, or you build houses out of wood, or you make painkiller from willow bark, or any of the other amazing things that happen with plants. You also breathe out carbon dioxide, and the plants can combine that with water to make more sugar again, using the energy from sunlight, and so the cycle continues.

Like most things in the story the natural sciences can tell about the world, it’s all so beautiful, so gracefully simple, yet so rewardingly complex, so neatly connected – not to mention true – that I can’t even begin to imagine why anyone would ever want to believe some New Age ‘alternative’ nonsense instead. I would go so far as to say that even if we are all under the control of a benevolent God, and the whole of reality turns out to be down to some flaky spiritual ‘energy’ that only alternative therapists can truly harness, that’s still neither so interesting nor so graceful as the most basic stuff I was taught at school about how plants work.

Is chlorophyll ‘high in oxygen’? No. It helps to make oxygen. In sunlight. And it’s pretty dark in your bowels: in fact, if there’s any light in there at all then something’s gone badly wrong. So any chlorophyll you eat will not create oxygen, and even if it did, even if Dr Gillian McKeith PhD stuck a searchlight right up your bum to prove her point, and your salad began photosynthesising, even if she insufflated your guts with carbon dioxide through a tube, to give the chloroplasts something to work with, and by some miracle you really did start to produce oxygen in there, you still wouldn’t absorb a significant amount of it through your bowel, because your bowel is adapted to absorb food, while your lungs are optimised to absorb oxygen. You do not have gills in your bowels. Neither, since we’ve mentioned them, do fish. And while we’re talking about it, you probably don’t want oxygen inside your abdomen anyway: in keyhole surgery, surgeons have to inflate your abdomen to help them see what they’re doing, but they don’t use oxygen, because there’s methane fart gas in there too, and we don’t want anyone catching fire on the inside. There is no oxygen in your bowel.

So who is this person, and how did she come to be teaching us about diet, on a prime-time television show, on a national terrestrial channel? What possible kind of science degree can she have, to be making such basic mistakes that a schoolkid would spot? Was this an isolated error? A one-off slip of the tongue? I think not.

Actually, I know not, because as soon as I saw that ridiculous quote I ordered some more McKeith books. Not only does she make the same mistake in numerous other places, but it seems to me that her understanding of even the most basic elements of science is deeply, strangely distorted. In You Are What You Eat (p.211) she says: ‘Each sprouting seed is packed with the nutritional energy needed to create a full grown healthy plant.’

This is hard to follow. Does a fully grown, healthy oak tree, a hundred feet tall, contain the same amount of energy as a tiny acorn? No. Does a fully grown, healthy sugarcane plant contain the same amount of nutritional energy – measure it in ‘calories’ if you like – as a sugarcane seed? No. Stop me if I’m boring you, in fact stop me if I’ve misunderstood something in what she’s said, but to me this seems like almost the same mistake as the photosynthesis thing, because that extra energy to grow a fully grown plant comes, again, from photosynthesis, where plants use light to turn carbon dioxide and water into sugar and then into everything else that plants are made of.

This is not an incidental issue, an obscure backwater of McKeith’s work, nor is it a question of which ‘school of thought’ you speak for: the ‘nutritional energy’ of a piece of food is one of the most important things you could possibly think of for a nutritionist to know about. I can tell you for a fact that the amount of nutritional energy you will get from eating one sugarcane seed is a hell of a lot less than you’d get from eating all the sugarcane from the plant that grew from it. These aren’t passing errors, or slips of the tongue (I have a policy, as it were, of not quibbling on spontaneous utterances, because we all deserve the chance to fluff): these are clear statements from published tomes.

Watching McKeith’s TV show with the eye of a doctor, it rapidly becomes clear that even here, frighteningly, she doesn’t seem to know what she’s talking about. She examines patients’ abdomens on an examination couch as if she is a doctor, and confidently announces that she can feel which organs are inflamed. But clinical examination is a fine art at the best of times, and what she is claiming is like identifying which fluffy toy someone has hidden under a mattress (you’re welcome to try this at home).

She claims to be able to identify lymphoedema, swollen ankles from fluid retention, and she almost does it right – at least, she kind of puts her fingers in roughly the right place, but only for about half a second, before triumphantly announcing her findings. If you’d like to borrow my second edition copy of Epstein and de Bono’s Clinical Examination (I don’t think there were many people in my year at medical school who didn’t buy a copy), you’ll discover that to examine for lymphoedema, you press firmly for around thirty seconds, to gently compress the exuded fluid out of the tissues, then take your fingers away, and look to see if they have left a dent behind.

In case you think I’m being selective, and only quoting McKeith’s most ridiculous moments, there’s more: the tongue is ‘a window to the organs – the right side shows what the gallbladder is up to, and the left side the liver’. Raised capillaries on your face are a sign of ‘digestive enzyme insufficiency – your body is screaming for food enzymes’. Thankfully, Gillian can sell you some food enzymes from her website. ‘Skid mark stools’ (she is obsessed with faeces and colonic irrigation) are ‘a sign of dampness inside the body – a very common condition in Britain’. If your stools are foul-smelling you are ‘sorely in need of digestive enzymes’. Again. Her treatment for pimples on the forehead – not pimples anywhere else, mind you, only on the forehead – is a regular enema. Cloudy urine is ‘a sign that your body is damp and acidic, due to eating the wrong foods’. The spleen is ‘your energy battery’.

So we have seen scientific facts – very basic ones – on which Dr McKeith seems to be mistaken. What of scientific process? She has claimed, repeatedly and to anyone who will listen, that she is engaged in clinical scientific research. Let’s step back a moment, because from everything I’ve said, you might reasonably assume that McKeith has been clearly branded as some kind of alternative therapy maverick. In fact, nothing could be further from the truth. This doctor has been presented, consistently, up front, by Channel 4, her own website, her management company and her books as a scientific authority on nutrition.

Many watching her TV show quite naturally assumed she was a medical doctor. And why not? There she was, examining patients, performing and interpreting blood tests, wearing a white coat, surrounded by test tubes, ‘Dr McKeith’, ‘the diet doctor’, giving diagnoses, talking authoritatively about treatment, using complex scientific terminology with all the authority she could muster, and sticking irrigation equipment nice and invasively right up into people’s rectums.

Now, to be fair, I should mention something about the doctorate, but I should also be clear: I don’t think this is the most important part of the story. It’s the funniest and most memorable part of the story, but the real action is whether McKeith is capable of truly behaving like the nutritional science academic she claims to be.

And the scholarliness of her work is a thing to behold. She produces lengthy documents that have an air of ‘referenciness’, with nice little superscript numbers, which talk about trials, and studies, and research, and papers … but when you follow the numbers, and check the references, it’s shocking how often they aren’t what she claimed them to be in the main body of the text, or they refer to funny little magazines and books, such as Delicious, Creative Living, Healthy Eating, and my favourite, Spiritual Nutrition and the Rainbow Diet, rather than proper academic journals.

She even does this in the book Miracle Superfood, which, we are told, is the published form of her PhD. ‘In laboratory experiments with anaemic animals, red-blood cell counts have returned to normal within four or five days when chlorophyll was given,’ she says. Her reference for this experimental data is a magazine called Health Store News. ‘In the heart,’ she explains, ‘chlorophyll aids in the transmission of nerve impulses that control contraction.’ A statement that is referenced to the second issue of a magazine called Earthletter. Fair enough, if that’s what you want to read – I’m bending over to be reasonable here – but it’s clearly not a suitable source to reference that claim. This is her PhD, remember.

To me this is cargo-cult science, as Professor Richard Feynman described it over thirty years ago, in reference to the similarities between pseudoscientists and the religious activities on a few small Melanesian islands in the 1950s:

During the war they saw aeroplanes with lots of good materials, and they want the same thing to happen now. So they’ve arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head as headphones and bars of bamboo sticking out like antennas – he’s the controller – and they wait for the aeroplanes to land. They’re doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn’t work. No aeroplanes land.

Like the rituals of the cargo cult, the form of McKeith’s pseudo-academic work is superficially correct: the superscript numbers are there, the technical words are scattered about, she talks about research and trials and findings – but the substance is lacking. I actually don’t find this very funny. It makes me quite depressed to think about her, sitting up, perhaps alone, studiously and earnestly typing this stuff out.

Should you feel sorry for her? One window into her world is the way in which she has responded to criticism: with statements that seem to be, well, wrong. It’s cautious to assume that she will do the same thing with anything that I write here, so in preparation for the rebuttals to come, let’s look at some of the rebuttals from the recent past.

In 2007, as has been noted, she was censured by the MHRA for selling a rather crass range of herbal sex pills called Fast Formula Horny Goat Weed Complex, advertised as having been shown by a ‘controlled study’ to promote sexual satisfaction, and sold with explicit medicinal claims. They were illegal for sale in the UK. She was ordered to remove the products from sale immediately. She complied – the alternative would have been prosecution – but her website announced that the sex pills had been withdrawn because of ‘the new EU licensing laws regarding herbal products’. She engaged in a spot of Europhobic banter with the Scottish Herald newspaper: ‘EU bureaucrats are clearly concerned that people in the UK are having too much good sex,’ she explained.

Nonsense. I contacted the MHRA, and they said: ‘This has nothing to do with new EU regulations. The information on the McKeith website is incorrect.’ Was it a mistake? ‘Ms McKeith’s organisation had already been made aware of the requirements of medicines legislation in previous years; there was no reason at all for all the products not to be compliant with the law.’ They went on. ‘The Wild Pink Yam and Horny Goat Weed products marketed by McKeith Research Ltd were never legal for sale in the UK.’

Then there is the matter of the CV. Dr McKeith’s PhD is from Clayton College of Natural Health, a nonaccredited correspondence course college, which unusually for an academic institution also sells its own range of vitamin pills through its website. Her masters degree is from the same august institution. At current Clayton prices, it’s $6,400 in fees for the PhD, and less for the masters, but if you pay for both at once you get a $300 discount (and if you really want to push the boat out, they have a package deal: two doctorates and a masters for $12,100 all in).

On her CV, posted on her management website, McKeith claimed to have a PhD from the rather good American College of Nutrition. When this was pointed out, her representative explained that this was merely a mistake, made by a Spanish work experience kid who posted the wrong CV. The attentive reader may have noticed that the very same claim about the American College of Nutrition was also in one of her books from several years previously.

In 2007 a regular from my website – I could barely contain my pride – took McKeith to the Advertising Standards Authority, complaining about her using the title ‘doctor’ on the basis of a qualification gained by correspondence course from a nonaccredited American college: and won. The ASA came to the view that McKeith’s advertising breached two clauses of the Committee of Advertising Practice code: ‘substantiation’ and ‘truthfulness’.

Dr McKeith sidestepped the publication of a damning ASA draft adjudication at the last minute by accepting – ‘voluntarily’ – not to call herself ‘doctor’ in her advertising any more. In the news coverage that followed, McKeith suggested that the adjudication was only concerned with whether she had presented herself as a medical doctor. Again, this is not true. A copy of that draft adjudication has fallen into my lap – imagine that – and it specifically says that people seeing the adverts would reasonably expect her to have either a medical degree, or a PhD from an accredited university.

She even managed to get one of her corrections into a profile on her in my own newspaper, the Guardian: ‘Doubt has also been cast on the value of McKeith’s certified membership of the American Association of Nutritional Consultants, especially since Guardian journalist Ben Goldacre managed to buy the same membership online for his dead cat for $60. McKeith’s spokeswoman says of this membership: “Gillian has ‘professional membership’, which is membership designed for practising nutritional and dietary professionals, and is distinct from ‘associate membership’, which is open to all individuals. To gain professional membership Gillian provided proof of her degree and three professional references.”’

Well. My dead cat Hettie is also a ‘certified professional member’ of the AANC. I have the certificate hanging in my loo. Perhaps it didn’t even occur to the journalist that McKeith could be wrong. More likely, in the tradition of nervous journalists, I suspect that she was hurried, on deadline, and felt she had to get McKeith’s ‘right of reply’ in, even if it cast doubts on – I’ll admit my beef here – my own hard-won investigative revelations about my dead cat. I mean, I don’t sign my dead cat up to bogus professional organisations for the good of my health, you know. It may sound disproportionate to suggest that I will continue to point out these obfuscations for as long as they are made, but I will, because to me, there is a strange fascination in tracking their true extent.

Although perhaps I should not be so bold. She has a libel case against the Sun over comments it made in 2004. The Sun is part of a large, wealthy media conglomerate, and it can protect itself with a large and well-remunerated legal team. Others can’t. A charming but obscure blogger called PhDiva made some relatively innocent comments about nutritionists, mentioning McKeith, and received a letter threatening costly legal action from Atkins Solicitors, ‘the reputation and brand-management specialists’. Google received a threatening legal letter simply for linking to – forgive me – a fairly obscure webpage on McKeith. She has also made legal threats to an excellently funny website called Eclectech for featuring an animated cartoon of her singing a silly song at around the time she was on Fame Academy.

Most of these legal tussles revolve around the issue of her qualifications, but such things shouldn’t be difficult or complicated. If anyone wanted to check my degrees, memberships or affiliations, they could call up the institutions concerned and get instant confirmation: job done. If you said I wasn’t a doctor, I wouldn’t sue you; I’d roar with laughter.

But if you contact the Australasian College of Health Sciences (Portland, Oregon), where McKeith has a ‘pending diploma in herbal medicine’, they say they can’t tell you anything about their students. If you contact Clayton College of Natural Health to ask where you can read her PhD, they say you can’t. What kind of organisations are these? If I said I had a PhD from Cambridge, US or UK (I have neither, and I claim no great authority), it would only take you a day to find it in their library.

These are perhaps petty episodes. But for me the most concerning aspect of the way she responds to questioning of her scientific ideas is exemplified by a story from 2000, when Dr McKeith approached a retired Professor of Nutritional Medicine from the University of London. Shortly after the publication of her book Living Food for Health, John Garrow wrote an article about some of the bizarre scientific claims Dr McKeith was making, and his piece was published in a fairly obscure medical newsletter. He was struck by the strength with which she presented her credentials as a scientist (‘I continue every day to research, test and write furiously so that you may benefit …’ etc.). He has since said that he assumed – like many others – that she was a proper doctor. Sorry: a medical doctor. Sorry: a qualified, conventional medical doctor who attended an accredited medical school.

In this book McKeith promised to explain how you can ‘boost your energy, heal your organs and cells, detoxify your body, strengthen your kidneys, improve your digestion, strengthen your immune system, reduce cholesterol and high blood pressure, break down fat, cellulose and starch, activate the enzyme energies of your body, strengthen your spleen and liver function, increase mental and physical endurance, regulate your blood sugar, and lessen hunger cravings and lose weight’.

These are not modest goals, but her thesis was that they were all possible with a diet rich in enzymes from ‘live’ raw food – fruit, vegetables, seeds, nuts, and especially live sprouts, which are ‘the food sources of digestive enzymes’. She even offered ‘combination living food powder for clinical purposes’, in case people didn’t want to change their diet, and explained that she used this for ‘clinical trials’ with patients at her clinic.

Garrow was sceptical of her claims. Apart from anything else, as Emeritus Professor of Human Nutrition at the University of London, he knew that human animals have their own digestive enzymes, and any plant enzyme you eat is likely to be digested like any other protein. As any Professor of Nutrition, and indeed many GCSE biology students, could tell you.

Garrow read McKeith’s book closely, as have I. These ‘clinical trials’ seemed to be a few anecdotes about how incredibly well her patients felt after seeing her. No controls, no placebo, no attempt to quantify or measure improvements. So Garrow made a modest proposal in a fairly obscure medical newsletter. I am quoting it in its entirety, partly because it is a rather elegantly written exposition of the scientific method by an eminent academic authority on the science of nutrition, but mainly because I want you to see how politely he stated his case:

I also am a clinical nutritionist, and I believe that many of the statements in this book are wrong. My hypothesis is that any benefits which Dr McKeith has observed in her patients who take her living food powder have nothing to do with their enzyme content. If I am correct, then patients given powder which has been heated above 118°F for twenty minutes will do just as well as patients given the active powder. This amount of heat would destroy all enzymes, but make little change to other nutrients apart from vitamin C, so both groups of patients should receive a small supplement of vitamin C (say 60mg/day). However, if Dr McKeith is correct, it should be easy to deduce from the boosting of energy, etc., which patients received the active powder and which the inactivated one.

Here, then, is a testable hypothesis by which nutritional science might be advanced. I hope that Dr McKeith’s instincts, as a fellow-scientist, will impel her to accept this challenge. As a further inducement I suggest we each post, say, £1,000, with an independent stakeholder. If we carry out the test, and I am proved wrong, she will of course collect my stake, and I will publish a fulsome apology in this newsletter. If the results show that she is wrong I will donate her stake to HealthWatch [a medical campaigning group], and suggest that she should tell the 1,500 patients on her waiting list that further research has shown that the claimed benefits of her diet have not been observed under controlled conditions. We scientists have a noble tradition of formally withdrawing our publications if subsequent research shows the results are not reproducible – don’t we?

Sadly, McKeith – who, to the best of my knowledge, despite all her claims about her extensive ‘research’, has never published in a proper ‘Pubmed-listed’ peer-reviewed academic journal – did not take up this offer to collaborate on a piece of research with a Professor of Nutrition. Instead, Garrow received a call from McKeith’s lawyer husband, Howard Magaziner, accusing him of defamation and promising legal action. Garrow, an immensely affable and relaxed old academic, shrugged this off with style. He told me, ‘I said, “Sue me.” I’m still waiting.’ His offer of £1,000 still stands.

But there is one vital issue we have not yet covered. Because despite the way she seems to respond to criticism or questioning of her ideas, her illegal penis pills, the unusually complicated story of her qualifications, despite her theatrical abusiveness, and the public humiliation pantomime of her shows, in which the emotionally vulnerable and obese cry on television, despite her apparently misunderstanding some of the most basic aspects of GCSE biology, despite doling out ‘scientific’ advice in a white coat, despite the dubious quality of the work she presents as somehow being of ‘academic’ standard, despite the unpleasantness of the food she endorses, there are still many who will claim: ‘You can say what you like about McKeith, but she has improved the nation’s diet.’

This is not to be shrugged off lightly. Let me be very clear, for I will say it once again: anyone who tells you to eat more fresh fruit and vegetables is all right by me. If that was the end of it, I’d be McKeith’s biggest fan, because I’m all in favour of ‘evidence-based interventions to improve the nation’s health’, as they used to say to us in medical school.

Let’s look at the evidence. Diet has been studied very extensively, and there are some things that we know with a fair degree of certainty: there is reasonably convincing evidence that having a diet rich in fresh fruit and vegetables, with natural sources of dietary fibre, avoiding obesity, moderating one’s intake of alcohol, cutting out cigarettes and taking physical exercise are protective against things such as cancer and heart disease.

Nutritionists don’t stop there, because they can’t: they have to manufacture complication, to justify the existence of their profession. These new nutritionists have a major commercial problem with the evidence. There’s nothing very professional or proprietary about ‘Eat your greens,’ so they have had to push things further. But unfortunately for them, the technical, confusing, overcomplicated, tinkering interventions that they promote – the enzymes, the exotic berries – are very frequently not supported by convincing evidence.

That’s not for lack of looking. This is not a case of the medical hegemony neglecting to address the holistic needs of the people. In many cases the research has been done, and has shown that the more specific claims of nutritionists are actually wrong. The fairy tale of antioxidants is a perfect example. Sensible dietary practices, which we all know about, still stand. But the unjustified, unnecessary overcomplication of this basic dietary advice is, to my mind, one of the greatest crimes of the nutritionist movement. As I have said, I don’t think it’s excessive to talk about consumers paralysed with confusion in supermarkets.

But it’s just as likely that they will be paralysed with fear. They may have a bad reputation for paternalism, but it’s hard to picture any doctor in the past century using McKeith’s consultation methods as a serious tactic for inducing lifestyle change in his patients. With McKeith we see fire and brimstone hailing down until her subjects cry on national television: a chocolate gravestone with your name on it in the garden; a shouty dressing-down in public for the obese. As a posture it is as seductive as it is telegenic, it has a sense of generating movement; but if you drag yourself away from the theatricality of souped-up recipe and lifestyle shows on telly, the evidence suggests that scare campaigns may not get people changing their behaviour in the long term.

What can you do? There’s the rub. The most important take-home message with diet and health is that anyone who ever expresses anything with certainty is basically wrong, because the evidence for cause and effect in this area is almost always weak and circumstantial, and changing an individual person’s diet may not even be where the action is.

What is the best evidence on the benefits of changing an individual person’s diet? There have been randomised controlled trials, for example – where you take a large group of people, change their diet, and compare their health outcomes with another group – but these have generally shown very disappointing results.

The Multiple Risk Factor Intervention Trial was one of the largest medical research projects ever undertaken in the history of mankind, involving over 12,866 men at risk of cardiovascular events, who went through the trial over seven years. These people were subjected to a phenomenal palaver: questionnaires, twenty-four-hour dietary recall interviews, three-day food records, regular visits, and more. On top of this, there were hugely energetic interventions which were supposed to change the lives of individuals, but which by necessity required that whole families’ eating patterns were transformed: so there were weekly group information sessions for participants – and their wives – individual work, counselling, an intensive education programme, and more. The results, to everyone’s disappointment, showed no benefit over the control group (who were not told to change their diet). The Women’s Health Initiative was another huge randomised controlled trial into dietary change, and it gave similarly gave negative results. They all tend to.

Why should this be? The reasons are fascinating, and a window into the complexities of changing health behaviour. I can only discuss a few here, but if you are genuinely interested in preventive medicine – and you can cope with uncertainty and the absence of quick-fix gimmicks – then may I recommend you pursue a career in it, because you won’t get on telly, but you will be both dealing in sense and doing good.

The most important thing to notice is that these trials require people to turn their entire lives upside down, and for about a decade. That’s a big ask: it’s hard enough to get people signed up for participating in a seven-week trial, let alone one that lasts seven years, and this has two interesting effects. Firstly, your participants probably won’t change their diets as much as you want them to; but far from being a failing, this is actually an excellent illustration of what happens in the real world: individual people do not, in reality, change their diets at the drop of a hat, alone, as individuals, for the long term. A dietary change probably requires a change in lifestyle, shopping habits, maybe even what’s in the shops, how you use your time, it might even require that you buy some cooking equipment, how your family relates to each other, change your work style, and so on.

Secondly, the people in your ‘control group’ will change their diets too: remember, they’ve agreed voluntarily to take part in a hugely intrusive seven-year-long project that could require massive lifestyle changes, so they may have a greater interest in health than the rest of your population. More than that, they’re also being weighed, measured, and quizzed about their diet, all at regular intervals. Diet and health are suddenly much more at the forefront of their minds. They will change too.

This is not to rubbish the role of diet in health – I bend over backwards to find some good in these studies – but it does reflect one of the most important issues, which is that you might not start with goji berries, or vitamin pills, or magic enzyme powders, and in fact you might not even start with an individual changing their diet. Piecemeal individual life changes – which go against the grain of your own life and your environment – are hard to make, and even harder to maintain. It’s important to see the individual – and the dramatic claims of all lifestyle nutritionists, for that matter – in a wider social context.

Reasonable benefits have been shown in intervention studies – like the North Karelia Project in Finland – where the public health gang have moved themselves in lock, stock and barrel to set about changing everything about an entire community’s behaviour, liaising with businesses to change the food in shops, modifying whole lifestyles, employing community educators and advocates, improving healthcare provision, and more, producing some benefits, if you accept that the methodology used justifies a causal inference. (It’s tricky to engineer a control group for this kind of study, so you have to make pragmatic decisions about study design, but read it online and decide for yourself: I’d call it a ‘large and promising case study’.)

There are fairly good grounds to believe that many of these lifestyle issues are, in fact, better addressed at the societal level. One of the most significant ‘lifestyle’ causes of death and disease, after all, is social class. To take a concrete example, I rent a flat in London’s Kentish Town on my modest junior medic’s salary (don’t believe what you read in the papers about doctors’ wages). This is largely a white, working-class area, and the adult male life expectancy is about seventy years. Two miles away, in Hampstead, where the millionaire entrepreneur Dr Gillian McKeith PhD owns a large property, surrounded by other wealthy middle-class people, male life expectancy is almost eighty years. I know this because I have the Annual Public Health Report for Camden open on my kitchen table right now.

The reason for this phenomenal disparity in life expectancy – the difference between a lengthy and rich retirement, and a very truncated one indeed – is not that the people in Hampstead are careful to eat goji berries and a handful of Brazil nuts every day, thus ensuring they’re not deficient in selenium, as per nutritionists’ advice. That’s a fantasy, and in some respects one of the most destructive features of the whole nutritionist project, graphically exemplified by McKeith: it’s a distraction from the real causes of ill health, but also – do stop me if I’m pushing this too far – in some respects, a manifesto of right-wing individualism. You are what you eat, and people die young because they deserve it. They choose death, through ignorance and laziness, but you choose life, fresh fish, olive oil, and that’s why you’re healthy. You’re going to see eighty. You deserve it. Not like them.

Back in the real world, genuine public health interventions to address the social and lifestyle causes of disease are far less lucrative, and far less of a spectacle, than anything a Gillian McKeith – or, more importantly, a television commissioning editor – would ever dream of dipping into. What prime-time TV series looks at food deserts created by giant supermarket chains, the very companies with which these stellar media nutritionists so often have their lucrative commercial contracts? Who puts the issue of social inequality driving health inequality onto our screens? Where’s the human interest in prohibiting the promotion of bad foods, facilitating access to healthier foods by means of taxation, or maintaining a clear labelling system?

Where is the spectacle in ‘enabling environments’ that naturally promote exercise, or urban planning that prioritises cyclists, pedestrians and public transport over the car? Or in reducing the ever-increasing inequality between senior executive and shop-floor pay? When did you ever hear about elegant ideas like ‘walking school buses’, or were stories about their benefits crowded out by the latest urgent front-page food fad news?

I don’t expect Dr Gillian McKeith, or anyone in the media, to address a single one of these issues, and neither do you: because if we are honest with ourselves we understand that these programmes are only partly about food, and much more about salacious and prurient voyeurism, tears, viewing figures and vaudeville.

Dr McKeith puts a cabbie straight

Here is my favourite Dr McKeith story, and it comes from her own book, Living Food for Health. She is in a cab, and the driver, Harry, has spotted her. He tries to spark up a friendly conversation by suggesting that fish contains more omega oils than flax. Dr McKeith disputes this: ‘Flax seeds contain far greater levels of the healthy oils (omega-3 and omega-6) in a properly balanced and assimilable form.’ When Harry disagrees, she replies: ‘What do you mean, you disagree? Have you spent years conducting clinical research, working with patients, lecturing, teaching, studying the omega oils in flax, obtaining worldwide data, compiling one of the largest private health libraries on the planet, and writing extensively on the topic? Are you a scientist, a biochemist, a botanist, or have you spent a lifetime studying food and biochemistry as I have done? Where is your scientific authority?’ Harry responds that his wife is a doctor, a gynaecologist. ‘Is she a food specialist or nutritional biochemist as well?’ demands Dr McKeith. ‘Um, ah, well, no, but she is a doctor.’

I am not a food specialist, nor am I a nutritional biochemist. In fact, as you know, I claim no special expertise whatsoever: I hope I can read and critically appraise medical academic literature – something common to all recent medical graduates – and I apply this pedestrian skill to the millionaire businesspeople who drive our culture’s understanding of science.

Flax seeds contain large amounts of fibre (along with oestrogenic compounds), so they’re not very ‘assimilable’, as Dr McKeith asserts, unless you crush them, in which case they taste foul. They’re sold as a laxative in doses of 15g, and you will need a lot of the stuff, partly because there’s also a problem with the form of omega oils in them: flax contains a short-chain plant form, and these must be converted in your body to the long-chain animal forms which may be beneficial (called DHA and EPA). When you account for the poor conversion in the body, then flax seeds and fish contain roughly the same amounts of omega oil.

We must also remember that we live not in a laboratory, but in the real world. It’s very easy to eat 100g of mackerel – if this were a completely different kind of book I’d be giving you my kedgeree recipe right now – whereas I would suggest that it’s slightly trickier to get a tablespoon of flax seed into you. Parsley, similarly, is a rich source of vitamin C, but you’re not going to eat an orange-sized lump of the stuff. As for Dr McKeith’s further claim that flax is ‘properly balanced’, I don’t know if she means spiritually or biologically, but fish is much higher in omega-3, which most people would say is better.

More importantly, why is everyone talking about omega-3? On to the next chapter.

Interestingly, Macfadden’s food product range was complemented by a more unusual invention of his own. The ‘Peniscope’ was a popular suction device designed to enlarge the male organ which is still used by many today, in a modestly updated form. Since this may be your only opportunity to learn about the data on penis enlargement, it’s worth mentioning that there is, in fact, some evidence that stretching devices can increase penis size. Gillian McKeith’s ‘Wild Pink’ and ‘Horny Goat Weed’ sex supplement pills, however, sold for ‘maintaining erections, orgasmic pleasure, ejaculation … lubrication, satisfaction, and arousal’, could claim no such evidence for efficacy (and in 2007, after much complaining, these seedy and rather old-fashioned products were declared illegal by the Medicines and Healthcare Products Regulatory Agency, or MHRA). I mention this only because, rather charmingly, it means that Macfadden’s Peniscope may have a better evidence base for its claims than either his own food products or McKeith’s Horny Goat penis pills.