This is a popular science book which attacks ultra-processed foods (UPF or UPFs) as being bad for human health, in particular being responsible for the increase in obesity and obesity-related diseases.
The crux of the thesis seems to be that UPFs are tastier than non-UPFs, that they are softer (and therefore easier to eat), that they are higher in calories, and that they are aggressively marketed; these four factors mean that people eat more and become fat.
In addition, some of the additives may be implicated in health problems, including inflammatory bowel diseases.
As someone who has been struggling to lose weight recently (according to my BMI, I was 'obese' and am now 'overweight'), I have some sympathy for some of the claims. There are some foodstuffs that do seem to be addictive (for me, digestive biscuits and Quorn cocktail sausages among others) and generally I find it difficult to stop eating once I have started (I also eat quickly, which is, according to this book, a genetic trait). I also have colitis which might have been caused by my diet.
However, I have major problems with this book. I trained as a scientist and the author is a respected scientist. Why then does this book exhibit so many of the features of pseudoscience?
- A lot of the evidence is anecdotal, including the author's own experience, that of his twin brother, and observations of his young daughter. He even includes one of his nightmares.
- He frequently attacks those involved in the production of UPFs, or those scientists who argue against him, often on the basis of their funding sources and sometimes because they work for companies who also produce non-food chemical products. Such attacks are 'ad hominem', a classic rhetorical trick widely recognised as a logical fallacy.
- Conversely, he paints rosy pictures of those scientists with whom he agrees. What is the relevance of, for example, their art collections? This is another rhetorical trick, designed to make the reader like these people and therefore more ready to believe them. It also approaches the logical fallacy of 'arguing from authority'.
- Similarly, he uses adjectives to influence the reader, either 'boo words' such as when he describes a critic as a "contrarian", or 'wow words' such as when he talks of "proper" sourdough bread. Once again, this is rhetoric, not scientific evidence.
- He adopts the 'speck in your eye' approach of focusing on criticising the arguments of his opponents while not holding his own arguments to the same standards (such as when he adopts the NOVA definition of UPFs while attacking nutritional information panels and traffic light labels on UK foods as being too complex).
- He attacks 'straw men' (another logical fallacy) such as when he attacks vitamin supplements: “There aren't any supplements that work for healthy people ... outside the context of possible deficiency vitamins supplements don't work.” (Ch 2). The whole point of supplements, as the word implies, is that they are for people who are deficient in a vitamin.
- He presents hypotheses and uses them as is they were facts, such as in "food produced for profit might be designed, deliberately or inadvertently, to make us consume it" (Ch 2) where the word 'might' means that the statement is not definitive, but it is swamped by the rest of the clause.
- Sometimes he uses the 'you never can tell' argument, such as in this passage commenting on the dimethylpolysiloxane in KFC Hot Wings. "Extensive experiments in rats show that hardly any is absorbed when eaten and it passes out unchanged in the faeces. Dimethylpolysiloxane may very well be safe. Or it may be subtly harmful over a long period through some mechanism yet to be discovered.” Here he admits that the scientific evidence shows this additive is safe, but he then dismisses this through the 'yet to be discovered' argument, which can be used to cast doubt on every scientific (and even pseudoscientific) argument.
In the text, rhetoric swamps evidence though, to be fair, there are a lot of footnotes linked to scientific papers.
However, my major criticism is the way in which he defines UPFs. He uses the cumbersome NOVA definition: "Industrially manufactured food products made up of several ingredients (formulations) including sugar, oils, fats and salt (generally in combination and in higher amounts than in processed foods) and food substances of no or rare culinary use (such as high-fructose corn syrup, hydrogenated oils, modified starches and protein isolates). Group 1 foods are absent or represent a small proportion of the ingredients in the formulation. Processes enabling the manufacture of ultra-processed foods include industrial techniques such as extrusion, moulding and pre-frying; application of additives including those whose function is to make the final product palatable or hyperpalatable such as flavours, colourants, non-sugar sweeteners and emulsifiers; and sophisticated packaging, usually with synthetic materials. Processes and ingredients here are designed to create highly profitable (low-cost ingredients, long shelf-life, emphatic branding), convenient (ready-to-(h)eat or to drink), tasteful alternatives to all other Nova food groups and to freshly prepared dishes and meals. Ultra-processed foods are operationally distinguishable from processed foods by the presence of food substances of no culinary use (varieties of sugars such as fructose, high-fructose corn syrup, 'fruit juice concentrates', invert sugar, maltodextrin, dextrose and lactose; modified starches; modified oils such as hydrogenated or interesterified oils; and protein sources such as hydrolysed proteins, soya protein isolate, gluten, casein, whey protein and 'mechanically separated meat') or of additives with cosmetic functions (flavours, flavour enhancers, colours, emulsifiers, emulsifying salts, sweeteners, thickeners and anti-foaming, bulking, carbonating, foaming, gelling and glazing agents) in their list of ingredients."
This definition is catch-all in the extreme. It seems to suggest that foods that are tasty and convenient to prepare are, by virtue of these attributes, UPFs. He acknowledges the complexity of this definition so he provides 'rule of thumb' alternatives:
- “UPF has a long formal scientific definition, but it can be boiled down to this: if it’s wrapped in plastic and has at least one ingredient that you would usually find in a standard home kitchen, it’s UPF.” (Introduction)
- “Almost every food that comes with a health claim in the packet is a UPF.” (Introduction)
- “My personal rule of thumb is: if I’m struggling with whether to call a food UPF then it probably is UPF.” (Ch 10)
- “Are you reading an ingredient list? That’s probably UPF.” (Afterword, FAQs)
The effect of these rules of thumb is to make the definition of UPF even more catch-all. And this is a major problem with the field. Because some food processing is good for us. The human gut has evolved since the invention of cooking; cooking allows us to extract more calories from our food (van Tulleken seems to suggest this is a bad thing because too many calories make us obese) and this might have been what drove the prehistorical increase in our brain size. The iodisation of cooking salt has not only prevented iodine deficiency diseases but there is evidence that it has increased the IQ of the global human population by an average of 4 IQ points. The flour used for most bread is supplemented, under UK law, with vitamins and, recently, folic acid in order to protect people from deficiency diseases (I recently read an article attacking the addition of folic acid and sneering that it was predicted to prevent 'only' between 100 and 150 cases of babies born with spina bifida). So a definition of UPF which can distinguish between what is 'good' processing and what is 'bad' seems to me essential. This is precisely what van Tulleken fails to provide. Instead, he seems to be encouraging us to eschew all processed food.
He does recognise that one of the major problems facing the elimination of UPFs is that they are cheaper and more convenient than non-UPFs. He accepts that this may be a problem for poor people (he cites figures suggesting that In the UK, because of the relatively high cost of housing, fuel and transport, in order to have a diet that adhered to the national healthy guidelines the poorest 50% would need to spend 30% of their income on food and the poorest 10% would need to spend 75% of their income on food). He has two solutions: firstly that they use cookbooks which will teach them how to make nutritious meals from cheap ingredients, and secondly that the savings he claims will be made from governments needing to spend less on healthcare (because there will be mush reduced obesity) can be used to subsidise foods. I suspect he is looking forward to the time when the pizza he buys made from "proper sourdough" costs the same as the supermarket pizza rather than more than five times the price. This seems utopian. And one thing he doesn't seem to consider is convenience. In the old days (the 1950s?) a typical family might have a mother who stayed at home and was able to pop out to the shops to buy food every day. Nowadays, a typical family may well need both parents to be 'breadwinners' and don't have the spare time for daily shopping. Foods with long shelf-lifes are therefore essential.
I agree absolutely that there should be rigorous governmental regulation of anything added to our food; the self-regulation system he describes in the US seems fraught with danger. Additives proved dangerous should be banned. Those sitting on regulatory bodies should be independent of the food industry, though I can't accept his suggestion that scientists employed by the food industry "should be rigorously excluded from the policy space and public debate. They shouldn’t be quoted in articles or appear on the news.” This seems to be anti-freedom of speech and very definitely anti-science which relies on ideas being tested through sceptical debate. I would applaud his suggestion of 'black hexagon' labelling for any food high in fat or sugar or salt. But the exclusion of certain foodstuffs from our diets must be done on the basis of the evidence and, for me, this book foregrounded rhetoric over science.
This review was written by
the author of Bally and Bro, Motherdarling
and The Kids of God


