My Lords, I am grateful to the noble Baroness for procuring today’s debate. She and I have long been two of a handful of parliamentarians who have taken an interest in obesity, concerned not only for those struggling with it but with the cost to the taxpayer and the NHS of the consequences of the unstoppable increases in adults and children, exacerbated as a result of lockdown.
During the pandemic, I wrote an article, “Hunk, Chunk or Drunk?” Unfortunately, many more people became the second or the third, rather than taking the opportunity to get fit. Today’s debate gives me the opportunity to raise concerns about the increased prevalence of UPF—ultra-processed food—to expand on what the noble Baroness has said and to discuss the effect on the nation’s health.
UPF has a long, formal scientific definition but it boils down to this: if it is wrapped in plastic and contains stuff that you do not typically find in a domestic kitchen, it is UPF. Flavours, flavour enhancers, colours, emulsifiers, artificial sweeteners, thickeners, foaming agents, bulking, carbonating, gelling and glazing agents—these additives are not the only ways that the food harms us but they are all harmful. Let us be clear: what we are talking about is not actually food. It is a set of substances reconstituted from commodity crops, processed and marketed to be addictive. Its sole purpose is financialised growth by transnational corporations that have repeatedly proven that they are unable to self-regulate. The entire food system is now built around UPF.
In our drift towards a diet based on these edible food-like substances and away from real food grown in the soil or reared in the fields, we risk losing the connection between soil, plants, animals and people for the health of our food and our planet. I reiterate that what characterises ultra-processed foods is that they are so altered that it is hard to recognise the underlying ingredients. These are concoctions of concoctions, engineered from ingredients that are already highly refined, such as cheap vegetable oils, flours, whey proteins and sugars, which are then whipped up into something more appetising with the help of industrial additives such as emulsifiers.
UPFs now account for more than half of all the calories eaten in the UK and US, and other countries are fast catching up. These foods, now simply part of the flavour of modern life, are convenient, affordable, highly profitable, strongly flavoured, aggressively marketed and on sale in supermarkets everywhere. Over half the energy from food eaten in the UK now comes from these products. They lead people to eat more and to put on weight at a time when already one in four adults and one in five children aged 10 to 11 in the UK are estimated to be obese.
Last year, to conduct research about the effects of UPF, Dr Chris van Tulleken did an experiment on his own body. He wanted to find out what would happen if he followed a diet high in ultra-processed food, and how it would interact with his body. He increased his usual intake of 30% UPF to 80% for four weeks, a diet which one in five people in the UK eat every day. We should be grateful to him for sharing what happened. It should be a wake-up call to us all.
After the month was over, Chris reported poor sleep, heartburn, unhappy feelings, anxiety, sluggishness and a low libido. He also had piles from constipation. “I felt 10 years older”, he said, “but I didn’t realise it was all about food until I stopped following the diet.”
Chris gained almost 7 kilos in the four weeks and moved from a healthy weight to being overweight. “If the weight gain continued at that rate for six months, I would have gained six stone,” he said. It did not stop there. Brain activity scans showed that the areas of his brain responsible for reward had linked up with the areas that drive repetitive, automatic behaviour. “Eating ultra-processed food became something my brain simply told me to do, without me even wanting it,” he said, adding that this is a similar brain response to taking substances we consider classically addictive, such as cigarettes, alcohol and drugs. The changes in brain activity were not permanent, but if UPF can do that much damage in four weeks to his 42 year-old brain, what is it doing to the fragile developing brains of our children?
We do not know exactly why ultra-processed foods have these effects, but most hypotheses come down to a combination of the physical act of processing and their nutrient make-up. Dr Kevin Hall of the National Institutes of Health tested two diets matched in terms of fat, sugar, salt and fibre content, but one was made up of unprocessed foods and the other of around 80% ultra-processed foods. The participants were able to eat the foods on offer until they wanted to stop.
His study found that those eating the ultra-processed diet ended up eating more than 500 calories per day more and gained almost one kilo of body weight over two weeks. Blood tests showed an increase in the hormone responsible for hunger and a decrease in the hormone that makes us feel full among the participants eating the diet high in UPF. These results were consistent with Chris’s experience. His hunger hormone increased by 30% during his experiment, which may have encouraged overconsumption. Dr Hall also found that participants on the UPF diet ate much more quickly than those on the minimally processed diet, which may also have contributed to the consumption of more calories. Chris experienced this too, as many of the foods are so easy to chew and swallow. Previous studies have suggested that eating slowly decreases hunger.
Chris found himself craving food much more often. Research has previously found that some foods, including ultra-processed pizzas, chocolate, crisps and cakes, can elicit cravings, loss of control and inability to cut back. There is evidence that foods high in carbohydrates and fat, as many ultra-processed foods are, can trigger the centres of the brain responsible for reward, emotion and motivation. A brain-imaging study suggests that the more often you experience reward from foods, the more you have to consume to sustain the same enjoyment. Many UPFs have also gone through focus groups to make them perfect. The taste, level of saltiness, mouthfeel, how much they need to be chewed and even the sound they make when eaten will have been fine-tuned.
Foods can be categorised as minimally processed or unprocessed, such as fresh tomatoes; processed, such as tinned tomatoes; and ultra-processed, such as store-bought tomato pasta sauce. Some ultra-processed foods are healthier than others. Wholegrain breakfast cereals, wholemeal sliced bread, tinned baked beans and unsweetened soy or plant-based drinks are all ultra-processed but have some nutritional benefits. Similarly, ready-made pasta sauces, ready meals, spreads and sliced meats can be reasonably healthy. Some pre-prepared foods are not ultra-processed, but any that include additives and chemicals not used in home cooking probably are. The availability, convenience and marketing of ultra-processed food makes it almost impossible to eliminate.
Chris’s experiment has been backed up with clinical studies and lots of laboratory work. The clinical study undertaken by Kevin Hall confirmed that the epidemiological findings were true: you can have those two diets matched for salt, sugar, fat, carbs and fibre and the UPF one will drive weight gain whereas the wholefood one will not. The problem is that it is now very normal for children and young people to eat 80% of their calories from UPF for the first two decades of their life. UPF now comprises 60% of what we eat in the UK and the US.
To sum it up, this is how UPF works. It is dry, which prolongs shelf life but also increases calorie density. It is soft, which increases speed of consumption, which is itself closely related to obesity. Flavour enhancers signal protein that never arrives. Artificial sweeteners prepare the body for sugars that do not arrive, and all the gums signal fat that never arrives. It contains additives that affect the microbiome and inflammation, as well having direct effects on the brain. It has addictive properties and is designed in a way so that the products that are most readily consumed and desired are the ones that succeed in the marketplace.
UPF is the cause of the childhood obesity pandemic. It is one of the leading causes of environmental destruction and climate change. I hope that I have persuaded noble Lords of the dangers of these so-called foods. What are they doing to our population? We need to act now, with urgency, before it is too late for the next generation.