We’re all eating too many calories and too much sugar, salt and saturated fat – but you don’t need me to tell you that.
However, the thing that has eluded scientists until recently is why.
After all, sugar, salt and fat have been cheap and available for a long time – but it’s only in the past few decades that obesity has soared. What happened?
‘Bliss-point’, ‘sonic branding’, ‘vanishing caloric density’, ‘snackification’, ‘stomach share’ and ‘hyperpalatability’ is what happened – these are just some of the terms that explain why food-related disease is fast overtaking tobacco as the leading cause of early death in this country and globally.
These terms refer to just some of the covert tactics being used by the food manufacturers with one aim in mind: to make us buy and eat more, and then still more.
These approaches are highly scientific, developed by the best minds, using MRI brain scanners and other techniques, in order to learn exactly how to hijack our unconscious desires.
This knowledge then informs the new products developed by food scientists – moreish, packaged foods.
These are made using industrial processes that you could not replicate in your own kitchen, with ingredients that you would not find in your home larder, what are now known as ultra-processed foods, or UPFs.
We need to bury the idea of the obesity crisis as a failure of willpower: that people are just making bad choices, writes Dr Chris Van Tulleken
But that’s not the main problem – the thing that drives consumption is the endless testing and perfecting of the recipe and every aspect of every food product to drive maximum consumption [i.e. make you buy and eat more of it], from the salt, fat and sugar ratio to the colour of the box.
These industrially made UPFs are driving a health catastrophe, with clear evidence from hundreds of studies showing they cause weight gain, obesity, some cancers, dementia, type 2 diabetes and (among other problems) early death from all causes.
Yet we cannot stop eating them: in the UK ultra-processed foods make up around 60 per cent of adult calories – and much more for many young people.
But the fact is, it’s not our fault.
All this is laid bare in Irresistible, a new documentary I’ve made with BBC Two, being broadcast next Monday. In it, you will hear not just from pro-nanny state public health bores like me, who you might argue have some ideological agenda, but from food industry insiders revealing exactly how they have engineered our food to be, well, irresistible.
In our documentary, the scientists who were right at the dawn of this billion-dollar industry explain the hidden tricks and techniques that have been perfected since the 1970s to get deep inside our minds and appetites, and to make ultra-processed food not just appealing, but addictive for many people.
We need to bury the idea of the obesity crisis as a failure of willpower: that people are just making bad choices; that they are somewhat lazy and it’s their fault. It’s not.
These products have been deliberately developed to drive excess consumption.
In the US, obesity started going up simultaneously in men and women; black, white and Hispanic groups of all ages at the same point: the mid-1970s.
It’s not plausible that they all lost moral responsibility simultaneously. Something else changed.
And this is where the story starts with an experimental psychologist in the US, called Dr Howard Moskowitz, who revolutionised the food industry by developing a concept called the ‘bliss point’.
Dr Moskowitz was contacted by the bosses at Campbell’s Soup to ask if he could help to make their pasta sauce sell better.
By trying 45 different versions of the sauce recipe on consumers and asking them to rate the deliciousness, he discovered that by hitting an optimum amount of sugar, fat or salt in a dish (more, but not too much), he could make people think that the entire recipe was better overall.
Food-related disease is fast overtaking tobacco as the leading cause of early death in this country and globally
Dr Moskowitz called this subliminal target the ‘bliss point’ – and he proved while working with the likes of Dr Pepper, Tropicana and Spam that by hitting the bliss points with the right combination of salt, fat and sugar, he could sell more product.
This has been a staple of UPF manufacturers’ strategies ever since. From that point on, food companies realised that if they employed scientific development processes they could sell us a lot more processed food.
But rather than relying on food-tasters’ subjective opinions of their products, some food companies began going much further to discover customers’ hidden preferences.
Professor Francis McGlone, the lead neuroscientist at the global food giant Unilever between 1995 and 2009, introduced MRI brain scanning to Unilever to ‘dig deeper’ into people’s preferences.
He explains: ‘We are not really aware of why we like what we like.’
So what he and his team did was put volunteers into brain scanners, then fed them ice cream to see what happened to their brains.
If you have found yourself unable to put an ice cream tub back in the freezer, then Professor McGlone’s findings may explain why.
‘Their brains’ orbitofrontal cortex reward systems were glowing like a furnace,’ Professor McGlone recalls.
‘This approach grew and grew as a way to predict what products would be successful.’
Brain scanning also showed that the texture of industrially produced food is massively important for making us crave it.
Professor McGlone says that soft food ‘short circuits’ our brain’s satiety mechanism so that we eat much more of it before we think we’ve had enough.
With a crunchy carrot we have to spend a lot of effort chewing it, which tells our brains we are consuming food and should expect to feel full. But soft foods bypass this. That’s handy for the UPF giants, because industrial manufacturing changes food textures and tends to make them much softer than natural foods.
Even apparently crunchy foods, such as all those cheesy orange puffs, are incredibly soft – so that you can easily crush them flat with your tongue.
There’s no satiety-creating resistance in them, and you keep eating more.
The food industry calls this money-spinning, craving-creating phenomenon ‘vanishing caloric density’. These snacks have an incredible amount of energy per gram, but you feel like you’ve eaten nothing.
But it’s not just the food itself that has changed. To sell us even more UPFs, the food giants have changed the culture of how we eat – increasing the number of times that we eat beyond our traditional three meals a day: snackification.
Some of the foods scientists I spoke to for the documentary had previously worked for the food industry – but had left, alarmed by the effect these UPFs were having on people.
Dr Yanaina Chavez-Ugalde, a research associate at the University of Cambridge, trained as a food engineer for Cargill, a huge corporation that makes most of the raw ingredients that go into processed food products. You will likely eat their ingredients multiple times per day.
After witnessing the effects of ever-growing influxes of packaged foods into her native Mexico, seeing the rise of obesity and related diseases, she changed career.
Now, instead, she examines the effects of UPF consumption on young people’s health.
Soft food ‘short circuits’ our brain’s satiety mechanism so that we eat much more of it before we think we’ve had enough
Dr Chavez-Ugalde says that big food companies are now fighting to win ‘stomach share’ from the competition – and one significant way in which they are doing this is by encouraging us to snack throughout the day.
‘Now the first snack of the day is a breakfast shake. It’s heavily marketed to consume on the go: do not sit down, do not take time to crunch through something,’ she says.
‘Snack number two, mid-morning, are protein bars… but often they are empty calories: energy-dense nutrient poor.’ Mid-afternoon snacks such as veggie straws are marketed as healthy, she continues. ‘But they are not actual food. Then there are post-gym snack bars that promise ‘energy protein’, and in the evening there are sharing snacks – big packets of crisps that you eat by yourself.’
The key piece of research that exposed the effect of UPFs on our eating habits was produced by Dr Kevin Hall, a senior investigator at the US National Institute of Health in Maryland in 2019 – this proved scientifically that ultra-processed diets really do drive us to eat more, thanks to their clever formulation.
He set up a seminal study, where 20 volunteers spent a month eating either an ultra-processed food diet or a natural food diet.
Both diets had the same levels of salt, sugar, fat, fibre and calories – however, the participants had the freedom to eat as much as they wanted.
Dr Hall assumed there would be ‘very little difference’ in the groups’ calorie intake. In fact he was surprised to find something completely different.
‘People on the ultra-processed diets spontaneously over-ate, about 500 calories per day more than people on the minimally processed food diets,’ he told me. ‘We found that the ultra-processed foods, despite being matched for their nutrient composition, tended to have many more calories per bite,’ Dr Hall adds. ‘The foods were also high in both sugar and fat, which is very rare in natural foods.’
This combination makes these foods hyper-palatable, triggering your brain’s reward system – so you want more.
As I’ve written in the Mail before, the food industry is trying to fight back against the evidence mounting against UPFs by creating a ‘parallel’ world of studies, industry-funded research to create confusion and doubt in consumers’ minds.
It’s a tactic right out of the playbook of the tobacco industry from the 1960s.
The question of course is, could the ultra-processed food industry stop producing such harmful, fattening foods?
John Ruff, a former executive at Kraft and the former General Foods from 1972 to 2008, does not believe that the food giants could, or indeed should, ever stop.
‘Companies spend a lot of time optimising all the aspects of their product, including flavour, taste and texture, to sell more,’ he told me.
‘That’s how the industry operates. Companies have to provide products that consumers want or otherwise they will go out of business.’
Ruff is correct. The job of food companies is not public health. But at the moment obesity alone costs the UK economy around £100 billion per year – far more than is recovered by taxation from UPF products.
The food is cheap when we buy it, but very expensive later on. And at the moment in the UK there is no warning on any food that would protect a child from buying it.
Yet in countries across Central and South America, legislators are bringing in polices that have been effective in tobacco control. In Colombia, for example, politicians voted to bring in taxes on UPFs, along with large, stark labelling warning that these products are high in sugar, or high in saturated fats or high in salt.
Harmful food needs clear warnings, we need to get the cartoon characters off the boxes and ban ads. The worst stuff needs to be properly taxed and we need to make real food much more affordable and available.
We need changes because as individuals, how can we expect to resist products which have been engineered and marketed by some of the smartest people on Earth?
If you are reading this and you are struggling with weight and diet-related disease, this film will show that it is absolutely not your fault. It really is the food. And it’s time that the Government stepped in to help stop it.
Irresistible: Why We Can’t Stop Eating, BBC Two, Monday, November 25, 9pm to 10pm. Also available on BBC iplayer.
Is this food addictive?
Food addiction is a growing field of study – and while I don’t think we should demonise any food, as an infectious diseases doctor, I see many patients who feel they are addicted to these products.
And certainly there is evidence that foods combining highly processed carbs with fat ‘converge’ on the same reward centres in the brain as addictive drugs, as Dr Ashley Gearhardt, a professor of psychology at the University of Michigan, told me.
How even the rustle of a crisp packet has been designed to tempt you
Even the noise made when we pick up a food packet has been carefully tweaked to make them sound irresistibly seductive.
The crinkly noises from packaging you find for crisps, for example, are carefully tuned to make you think, ‘fresh, fresh, fresh’, according to Professor Barry Smith, who is a sensory consultant to the food industry.
‘Sound engineers and manufacturers work really hard to get the sound of their products just right,’ he told me. He calls it ‘sonic branding’.
Even the noise made when we pick up a food packet has been carefully tweaked to make them sound irresistibly seductive
He explains: ‘For example, when you pull open the ring on a can of fizzy soda, you’ve got two noises: the click and the tear. And that is sonic branding.’
This idea that a brand can express itself – and spark your craving instincts – through signature sounds, is exemplified by one of the many companies on whose sonic branding Professor Smith has worked – Kellogg’s.
‘When they asked me to explain sonic branding, I told them: ‘You invented it!’ Most people will remember as children lifting a bowl to their ear to hear the ‘snap, crackle and pop’ of Rice Krispies. That’s sonic branding at its best, and that’s the original.’
