It is barely ten years since Denmark repealed its infamous “fat tax”. It was supposed to be a world-leading intervention to tackle obesity but it proved to be hugely unpopular and lasted just 15 months.

It seems almost strange now that it targeted saturated fat

It seems almost strange now that it targeted saturated fat. In hindsight, it was the last gasp of the crusade against fat before all eyes turned to sugar. The anti-sugar crusade seemed to come out of nowhere in 2014 with the emergence of the tiny but phenomenally successful pressure group Action on Sugar. Within three years, the British government had announced a tax on sugary drinks, but by then the anti-sugar movement was morphing into a campaign against carbohydrates. That began to run out of steam a couple of years ago when many of the leading anti-carb personalities found that they could get more attention — and, dare I say, money — from being “sceptical” about COVID-19 vaccines.

They come and go, these food fads, but they all rely on the belief that there is something in the food supply that is uniquely dangerous, something hitherto unknown that only independent free thinkers can see is the cause of all our problems.

The new dietary villain is “ultra-processed food” (UPF), a concept that didn’t even exist until a few years ago but is now everywhere. There have been two books about UPF published in recent weeks and a third — Henry Dimbleby’s Ravenous — dedicated a lot of space to it.

The simple definition of ultra-processed food as used by those who are concerned about them (I am not making this up to make them sound silly) is anything that is “wrapped in plastic and has at least one ingredient you wouldn’t find in a home kitchen”. Since you probably don’t have emulsifiers, preservatives and artificial sweeteners in your kitchen, this rules out a lot of products.

The argument is that these products make you fat and should be avoided. The evidence for this comes from a study published in 2019. In a randomised controlled trial, ten people were given an ultra-processed diet and ten other people were given an unprocessed diet. Both diets were similar in their overall sugar, fat, protein and salt content, although the meals themselves were very different.

The participants were given all the food for free and they could eat as much as wanted. The people on the ultra-processed diet ended up eating 500 calories per day more than the other group and, after two weeks, had put on nearly a kilogram of weight. By contrast, the people on the unprocessed diet lost weight.

If you look at the food that was offered to the two groups, the explanation is obvious. The meals and snacks available to the UPF group were delicious whereas the food given to the other group was rather Spartan and was unlikely to make anybody ask for a second helping. If you give people tasty food for free, they will tend to eat more of it.

The food industry is good at making tasty food. That is their job. Many of the “ingredients you wouldn’t find in a home kitchen” are used to make the food tasty (others are there to make it safer and increase its shelf-life), but they are not inherently fattening or dangerous.

Unfortunately, the common sense interpretation of the 2019 study — that tastier food is more likely to be over-eaten than less tasty food — has turned into a belief that any additive used in food manufacturing that isn’t familiar to a non-scientist is going to kill you. The suggestion now is that ultra-processed food is inherently fattening regardless of how many calories you consume.

This has rapidly degenerated into a theatre of the absurd

This has rapidly degenerated into a theatre of the absurd. Chris van Tulleken (the author of Ultra-Processed People) recently appeared in the Daily Mail panicking about Hovis Multigrain Seed Sensations because it contains a perfectly harmless emulsifier and “ascorbic acid” (AKA vitamin C). He then appeared on television to warn people that they will need to have their wisdom teeth removed because supermarket bread has changed the shape of their jaws.

This week, The Times told its readers how to avoid putting ultra-processed food in their shopping baskets. With the help of a nutritionist who thinks that “we should put warning signs on UPFs so that people know they’re not good for your health”, they rejected Hellmann’s mayonnaise because it contains “modified maize starch, sugar and natural flavouring”. Cholula Hot Sauce was rejected because it contains “the stabiliser xanthan gum”. Baked beans were rejected because they contain modified cornflour. Warburton’s crumpets were rejected because they contain “three e-numbers and a preservative”. A brand of Pesto was rejected because it contains “maize fibre, whey powder and flavourings”.

At no point were readers of The Times told how these ingredients were going to do them harm. What exactly is wrong with eating whey powder or modified cornflour? Xanthan gum is actually rather good for you. So is maize fibre. Preservatives stop food going off too quickly. Isn’t that a good thing?

None of this stuff is in a typical household kitchen, but that is a preposterous reason not to eat it. Two of the few ingredients that are in everybody’s kitchen are sugar and salt. Should we eat more of those instead?

One doesn’t need to poke the anti-UPF ideology too hard to see that it has nothing to do with science or nutrition. According to The Times, biscuits are fine so long as they don’t contain emulsifiers. So is chocolate. Crisps are fine so long as they are cooked in olive oil and cost £4.99 a pack. Bread is OK so long as it’s sourdough and comes from Waitrose.

The snobbery that has always been in the shadows of the healthy eating movement is out and proud in the anti-UPF movement. The message is that you can eat what you like so long as you make it yourself, get a chef to make it for you, or buy it from an artisan shop. Salt, sugar and fat is back on the menu so long as you don’t buy it from Asda.

One of the reasons people mistakenly believe that a healthy diet is expensive is that they wrongly assume expensive food to be healthy. No one wants to believe this more than people who buy expensive food. The anti-UFP agenda is tailor-made to justify their lifestyles. It appeals not only to status-signalling food faddists, but to back-to-the-land reactionaries, anti-capitalist hipsters, people who suffer from chemophobia (fear of chemicals) and those who suffer from orthorexia (a “pathological fixation associated with consuming healthy food”). In other words, a large chunk of Britain’s middle class.

Whether it will survive its first contact with mainstream public opinion remains to be seen, but the idea of warning labels being put on wholemeal bread is a less distant proposition today than it was a year ago.