The Diet Myth:The Real Science Behind What We Eat

Date Reviewed
April 1st 2016



You can make your 'own cheese', the 'ultimate selfie', with a swab from your armpit, navel and between your toes for an appropriate microbe sampling to apply to the milk.


And if you can get past this idea, the author, Tim Spector, a British professor of genetic epidemiology presents a subtle, comprehensive, imaginative, yet scientific look at a subject that many obsess over, their diet.


With occasional humorous turns of phrase, he doesn't preach pat fight-the-fat formulas for what to do. And in this age of rapidly advancing knowledge, this book may remain the 'bible' on the subject, longer than most.


One of the striking ideas presented is that “people who eat the same thing” are “not necessarily eating the same thing”. And that, he says, is because individuals have different biomes, different genes and different enzymes and hence a different rendering of food. Whether you pack on excess weight with fats or carbohydrates depends on genes and microbes.


And it is the focus on the micro biome as the central feature that is special about this treatment of the subject. Personal lifestyles, foods chosen and nutrition and properties of individual foods are like the branches on a tree for which the biome is the trunk.


And he follows this into such seemingly divergent considerations as natural childbirth versus caesarian section, early childhood doses of antibiotics and obsession with cleanliness. And he links this to such recently exploding conditions as food allergies and several other 'newly popular' diseases.


While personal lifestyle choices are not off the hook, there is some credence in my-body-made-it-happen-and-I-am-not-responsible. One of his most salient statements is “the diminution in our microbes and our processed, sugary, fatty diets have joined forces to produce the perfect obesity storm.” And dieting for weight loss is nearly as much of an epidemic as obesity. Concern over nutrition is a distant consideration.


Imbedded in his account, although not specifically indicated, is the human predisposition to latch onto something; a food, a practice, a medicine, a supplement that is good and beneficial in constrained doses and promote and consume it past the point of benefit to unnecessary and eventually harmful levels. Something basically beneficial may be over promoted and interpreted out of context.


A recurring theme is that “there is little good evidence of any health benefits or harm potential of any particular food.” So not surprisingly he doesn't advocate many as positive, but he will defend some of the maligned as not necessarily bad. Further, he says, that the difficulty to apply controlled food experiments to humans means that correlations and general observations have to suffice and these can result in misleading conclusions.


Diet prescriptions don't work the same on all people because of the unique factors responsible for rendering the food, says the author. Some work as promised for some, but not others, and some don't work for anybody.


However, those selling one-diet-fits-all are more focussed on the sale than the success of the diet, although success would help in future sales.


This illustrates how much the formulaic average is relied on. Spector points to the body mass index BMI yielded number used to determine what is right and wrong in people's weight/height relationship. Less than 25 is okay. He cited a rugby team where the average weight was 100 kg. and the BMI 29. People fearfully hesitated telling them that all were “overweight” and some “obese”. What was missing in the verdict was that their average fat percentage was 11, making them much leaner than average, rendering the BMI meaningless.


Near the end of the book, the author suggests the idea that future diets may be customized for each person based on biome and genetics combined with the modern ability to gather and organize huge volumes of data.


Most 'diets' are about losing weight in the progressively obese wealthy societies. One commentator answered the question 'why are diets so popular and numerous?”, with “that is because they don't work”. And the reduction in dieting suggest the public may be now buying into the idea, says Spector.

While Spector may allude to this, his tone is not so brazen. And while he doesn't paraphrase Jack Lalanne's “if man made it don't eat it” , he uses the similar “don't eat anything your great-grandmother's microbes wouldn't recognize as food” as he chastises modern processed foods.


A prominent exception, and maybe not really a processed food, are cheeses and yoghurts. The rationale here may be that they are made by microbes that are useful in food digestion for most people. And ingestion of these adds to the microbe complement of the biome.


On the other end, trans fats, a concoction of the processed food industry, is deemed to have only health diminishing qualities, whatever advantage they may provide the industry.


While he gently corrects innocently transmitted myths, he is more ruthless with the malevolent commercial claims based on poor and deliberately misleading 'science'.


And diversity of the human biome, composed of about 100 trillion tiny organisms weighing three to four pounds, is a foundation of human health.


As one might expect with somebody who continually investigates a subject, there are fewer firm declarations about individual foods, than are made by 'diet merchants' and 'diet seekers'.


The only food that is given much credibility as a silver bullet is extra virgin olive oil. Next in line here might be garlic followed by natural cheese and yoghurt, for their contribution to the biome. And he generally favours the diverse mix of the “Mediterranean diet”, which he admits he prefers.


He touches on many of the 'famous' diets and trends. One trend that is treated particularly unmercifully is the idea of exorcising 'toxins' form the body. He calls the idea “mumbo jumbo” with science rivalling bloodletting and leeches of the middle ages.


Spector says that a variety of colours in fresh, non processed foods, is a general indication of a balanced diet. This idea is reflected in the cover photo on the book, which includes chocolate, pasta, carrots, broccoli, cheese, bananas, peanuts, grapes and beef.


The water drinking mania, prescribing eight glasses of water daily for everybody, is dismissed but treated a little more gently. We survived the hunter gather stage “without taking a slug out of a water bottle every five minutes”.


Precis Portion


There is little criticism of vegetarians, but a little more concern about vegan-ism. While generally he advises much less red meat than is popular in Britain and the U.S., he comes down slightly favouring some meat “for health”. He suggests that vegetarians surprise their microbes with one steak a year.


Caffeine beverages and alcohol come out a little better than neutral in small amounts, up to four cups of coffee a day and one glass of wine. In both cases his support is based more on a predominance of anecdotal “evidence” than on a lot of rigorous science, which he doubts is possible.


And he points out that while fats, carbohydrates and proteins, have an expected 'normal' use in the body, that is not necessarily what happens in all cases. Ingestion of sugar may be a greater contributor to excess fat stores in bodies than either fat or carbohydrates. Eating cholesterol high foods doesn't mean one's cholesterol will be high. That could be determined by genes and microbes and how they work in the individual.


He mentions that Greeks living on the island of Crete as having among the highest fat diets in the world, but still one of the healthiest.


Cubans eat twice the sugar of Americans, yet are healthier. So even utilization of sugar is complicated. He says that dieting advice and official recommendations may not be wrong, but simplistic.


Diet action may be taken without appreciating that the body may make its own evolutionarily programmed adjustments in response and this is why most diets fail, he says. Many physicians and health experts don't appreciate the newly discovered layers of biological complexity. Counting calories in and calories out with exercise and cutting out some foods is a myth for losing weight, he says.


Environment may be only slightly more important than genes in energy expenditure, he adds.

This idea sees more resistance and infighting in health/medical professions than any other subject and much unsupported by science, he says. He terms 'failure to account for microbes', as the biggest gap in diet science.


Since the mid-20th century many businesses have fostered and capitalized on the mania to kill germs (microbes) although only a few are harmful and many crucial to our health. One significant void in modern health, and a contributor to obesity, is the decreasing variety of microbes in our guts, he says. Restricted diets may contribute to this. Intermittent fasting may help.


Hunter gatherers may have ingested 150 different ingredients a week, now that may be down to 20.


Obsession with poorly calculated and lack of discrimination in the nature of calories in diets doesn't help.


The genetic propensity to retain fat may have been an evolutionary defence against disease as well as famine.


The recent obesity crisis has generally seen the lean stay lean and the slightly chubby get obese, suggesting genetic factors along with environment.


There are indications that the obesity epidemic may hit Asian populations harder than Americans, he says.


He also points out that people may have genetic predispositions to 'packages' of tastes and the consequences of such.


Further there may be genetic inclination toward exercise, and how much of what kind is necessary is an idea in constant flux as well. Our bodies may adjust to exercise and not by losing weight. It is harder to get rid of fat than muscle. And while it remains beneficial to exercise, it is becoming clearer that exercise has less bearing on weight loss than previously believed. But also fitness has more bearing on health than obesity.


While there is no definitive conviction on the optimum amount of exercise, there is some consensus around 45-60 minutes per day. Here again microbes are likely involved and exercise increases biome richness.


He discusses fats, carbohydrates and protein. One of his early salient comments is “cholesterol has been wrongly framed as the arch-criminal it never was”. It is part of almost every cell in our body and 80 per cent is synthesized and only 20 per cent eaten. And on fat.... it makes up a third of our bodyweight and is indispensable. And consumers shouldn't reflexively grab the zero and low fat option without finding out more, he recommends. Treat the 'zero fat' sticker as a sign of processing not of health.


The French have much of their diet based on living things like cheese, yoghurt and wine. And usually a lot of fat in the first two, but only about one per cent is cholesterol. The U.S. FDA promotes industrial sterile cheese with little living bacteria. And full fat 'natural' cheese is now found to, by “observational epidemiological studies”, protect against heart disease.


Trans-fats constructed by and for the interests of the food industry are detrimental to health and are resisting elimination because of industry lobby. They may well still have a home in the 'fast foods'. As with other food choices, he doesn't proscribe them completely, but says only eat 'fast food' rarely and counter the effects with probiotic and high fibre foods.


One of the main knocks against processed foods, he says, is that 80 per cent are made up of four ingredients...corn, wheat, soy and meat. And these ingredients are bolstered by government subsidies combined with massive advertising leading to over consumption.


On the protein front, he points out that vegetarians and vegans can get a normal amount of protein, but have to eat more. Vitamin B12, zinc and iron are the vulnerabilities of no meat, and only a small amount of meat is required for this.


High protein diets to loose weight utilize protein and fat for energy and in the absence of carbohydrates, a more inefficient source, people lose weight, at least initially. In addition, these foods more readily produce satiation.


The vulnerability of the paleo diet, outside of its prohibitions on useful food, is that it doesn't take into account the change in humans, particularly their biome which adapts rapidly to new foods.


He points out that the modern human biome is less diverse than the past with some microbes possibly having gone extinct with pesticide and antibiotic use.


And sometimes people may live healthily on a restricted 'unhealthy' diet for a long period of time then with a sudden change in diet, that may not seem unhealthy, their health suffers. Here, says Spector, their microbes may have adjusted to the previous food, but not had sufficient time to adjust to the new diet.


Spector casts doubts on the universal benefit of refined soy protein, battling for health accolades in the North American and European market. He also suggests that gut microbes in this part of the world may not digest the food as well as in Asia.


Seaweed is another food, recently introduced, for which people in western countries may not yet have the microbes to properly digest. But here again our microbes can adapt.


Both of these may parallel adaptation to milk, not yet common in Asia. Spector is a proponent of dairy products, calling it a “slight health benefit and the cruder and less processed the better” and devotes a chapter to them. “The lactase gene mutation was a major event that allowed the gene to stay switched on permanently in adulthood.”


He launches his carbohydrate chapter with “sugar is the most dangerous drug of the times”. The components of sucrose (a carbohydrate) are glucose (natural fuel of our bodies) and fructose, the 'villain'.


And one of the villainous forms, besides the obvious soft drinks, are fruit juices with the countervailing components of fibre stripped. This fibre slows the absorption of sugar and allows time for marshalling of the desired microbes. And sugar is taking over from fat as the primary enemy. And the danger is disguised in food industry labelling.


Sugar has a propensity to interact with our 'fat' genes.


While the science seems quite convincing of the health dangers of sugar, governments have been reluctant to put limits on it and in the U.S. the corn-sugar lobby works against it. Denmark, however, has moved ahead aggressively. Worldwide, sugar is cheap and subsidized by taxpayers.


The health of the biome, he says is a function of diversity, which in turn is largely a function of diversity in foods eaten. As people age often biome diversity declines. Studies, he says, found that institutionalized and frail seniors usually have a less vigorous biome. Possibly it is both cause and effect.


Lack of complex carbohydrates from fresh fruits and vegetables may be an underlying cause. While humans have only 30 of their own enzymes to break down food, their microbes have over 6,000 to help with the job. Humans may have fewer enzymes now with cooked food, than they did surviving on raw food, he adds.


He discusses fasting and the first myth he identifies that breakfasts are compulsory. Fasting may improve biome diversity, he says. We should let our bodies decide mealtimes not dogma and guidelines.


He also chides the 'superfood' idea explaining that many natural foods are 'super-foods', but may not work in isolation, but in conjunction with other foods.


The average western diet, he says, is deficient in fibre and carbohydrates from vegetable and fruit.


In a poignant revelation, he indicates, a 'symptom' of high fibre diet. Spector cites the Kalahari Bushmen as regularly producing two-pound turds compared to the average “civilized” European offering of four ounces. At the same time, he was castigating ´modern trends of refining carbohydrates by removing the fibre.


And he clarifies prebiotics. Not all fibre is prebiotic, but “all prebiotics are by definition non-digestible fibres”. And this is closely associated with healthy microbes. With a reduction in use of fibrous vegetables in the U.S., bread, by default, is the main source of fibre.


People who confidently made the move from sugar to 'harmless' artificial sweeteners may not be getting the desired benefits. Microbial change in response to these chemicals may lead to even more fat being laid down as well as other subtle changes.


And for those who have habits and treats they like, Spector is not a party pooper. Coffee up to four cups a day, wine to one glass a day and dark chocolate, all pass, as possibly beneficial or at least with no evidence of harm. Pure cocoa is beneficial, but not so much fun, food. Coffee is high fibre and described as 'a complex food'. As a bonus, penchant for these 'transgressions' could be blamed on your microbes and genes.


Alcohol enjoyment depends on a few key enzymes. East Asians predominate in lactose intolerance and also alcohol intolerance, metabolizing it 50 times faster than Europeans and Africans. It could be construed that the “west was won” based on the alcohol intolerance of the native people.


Caffeine, like fructose, is a popular food additive to enhance addiction.


Another myth subscribed to by lots of people. “Many young people nowadays go about with plastic water bottles_full of chemicals and devoid of microbes_attached to their person, for fear of dehydration.” “Our bodies are perfectly adapted to tell us when we are thirsty.”


And while off the main topic, but of interest “characteristics of aggressive behaviour, extreme conservative views and even religious beliefs have a significant (around 50 per cent) genetic influence.”


He states that the foods we “choose to eat are less healthy than 50 or even 30 years ago” much due to processing and the removal of “original nutrients”. Eating a balanced diet including fresh vegetables and fruit and the occasional piece of meat should suffice for 99 per cent, but the upsurge in vitamin and supplement sales suggests we aren't convinced. Lure of a magic bullet may be part. Excess of 'beneficial' supplements is more danger than a dearth of them.


There is little scientific evidence, he says, for the use of supplements generally.


He deals briefly with antibiotic overuse citing all countries as guilty but Denmark and Sweden, with centralized health care, the least, and half the usage of the U.S. He particularly notes the negative effect on microbes of babies and children from over consumption and most courses are unnecessary. He says there is a correlation between high antibiotic use and obesity.


Babies get their first bath in microbes from the vaginal canal during birth and this is missed with Caesarian birth and relatively recently understood as a void effecting their life and immune system going ahead. He termed the C-section as “messing with powerful evolutionary forces”. Transfer of microbes parallels genes. And this void also has a correlation with later obesity, he adds.


And all of the problems are compounded by second hand antibiotics in animal-based food and water.


He devotes a chapter to food allergies and ties it in with nuts. One's microbes are responsible for freeing nutrients, primarily fats, protein and polyphenols from the toughest of nuts.


Spector points out that first medical mention of food allergies was in 1912 and the first mention in a medical journal 1969. Now they are so common as to have warnings posted about foods. One in fifty children have a peanut allergy in Australia (1 in 80 UK) with rates seemingly doubling every 20 years. Now one in 20 children is allergic to peanuts, milk or other foods.


He says a diverse biome at birth appears essential in reducing these allergies. Biomes in bottle fed babies seem less rich and correlated with weaker immune systems.


More time playing inside in hyper clean and germ-routed houses also seems related with food allergies. This phobia took off in the 1960s. The rough and tumble childhood of dirt, worms, animals and mild diseases was eschewed by the 'tuned-in' parent.


All of this may tie in with the contention that the health of society is decreasing. An interesting parallel may be that we are killing off micro life forms as well as macro at our peril.


Resisting the allergy epidemic, maybe not surprisingly, are the Amish, who have resisted a lot of other 'improvements', such as pasteurized milk.


The increasing popularity of pets, with their microbes may be a trend against over clean. But steeped in germ extermination it will take a leap to “embrace dirt and diversity as our friends” but it could be crucial to the health of the next generation.


Spector recommends people treat “best before” as an “estimate of food quality, not of safety”. Supplanting this idea in the EU are “use by” dates. Of course manufacturers benefit if you trash food while it is still useable.


On a related issue most food infections occur before you buy the product, not while it is aging in your fridge.


And a profound statement “until we change our exaggerated fear of microbes we will find it hard to make the right moral and health decisions.”


And a warning “microbial diversity is declining every decade, which is definitely a bad thing and likely to be a major contributor to the modern epidemics of allergy, auto-immune disease, obesity and diabetes.”


He suggests reducing meat to one or two times per month as a minimum. He even suggests a “junk food blowout” once a year and a “greasy fry-up” for breakfast. This may be part of hormesis where you take a little bit of something that is noxious, if not worse, to exercise one's system. Hygiene should be redefined and bothered less about.