What are UPFs (Ultra-processed foods) – and why are they now considered so harmful? And what do all those things listed on food labels actually mean? To find the answers, we spoke to leading experts about how to read labels to identify the foods that put your health at risk, in this unique guide.
Until recently, few people outside of research labs had heard of ultra-processed foods – yet now they are in the spotlight as a mounting body of research links them with the risk of health problems including obesity, heart disease, type 2 diabetes, some cancers, depression, dementia and even early death.
It’s not just the usual culprits – mass-produced ice cream, fizzy drinks and packaged snacks – that we are talking about. Ultra-processed foods, or UPFs, now include a huge range of everyday foods from packaged bread to dairy products and 'healthy’ plant-based meals, making them nigh impossible to avoid.
High in fat, sugar or salt (or all three), they’re designed to be impossible to resist.
To add to the confusion, it’s clear that not all UPFs are potentially equally harmful.
Earlier this year, researchers at University College London (UCL) found some UPFs – including savoury snacks, processed meats, ready meals and sweet drinks – were linked to a higher risk of developing type 2 diabetes than others, such as packaged bread and cereals.
Rachel Batterham, a professor of obesity, diabetes and endocrinology and one of the co-authors, said: 'This study… confirms that not all foods categorised as UPFs are alike in terms of the health risks associated with them.’
So it’s hardly surprising that shoppers are baffled. The term was coined in 2009 by scientists at the University of Sao Paulo in Brazil, who were researching the alarming rise in obesity among young children.
Ultra-processed foods, or UPFs, now include a huge range of everyday foods from packaged bread to dairy products and 'healthy’ plant-based meals, making them nigh impossible to avoid
Nutritional epidemiologist Dr Carlos Monteiro and his team analysed food-buying patterns to see what had changed: they found that people were buying less salt, cooking oils and raw ingredients such as beans and rice and more processed foods such as fizzy drinks, instant noodles, packaged breads and biscuits.
To describe the food, Dr Monteiro introduced the term ultra-processed – 'industrial formulations made entirely, or mostly, from substances extracted from foods’, plus additives with little (if any) unprocessed food, he wrote in the journal Public Health Nutrition. The label has stuck.
As part of his work identifying exactly why UPFs differed from other foods, Dr Monteiro and his team also came up with a food classification system, called Nova (the Portuguese word for 'new’).
This identified four categories – unlike current food labels, which tell you about the nutrients, Nova grades foods according to how processed they are.
Nova 1 covers minimally processed, natural ingredients, such as fruit, vegetables, meat and fish.
Nova 2 are cooking ingredients processed from raw ingredients, such as oil, salt, butter.
Nova 3 are processed foods made by adding culinary ingredients to raw ingredients, such as fresh bread and canned veg. Canning, pasteurising, freezing and drying are all forms of processing.
Nova 4 are industrially processed foods that couldn’t be produced in a home kitchen. That’s UPFs.
Food processing is nothing new: canning, freezing and pasteurising have existed for decades.
Many foods we eat have been processed to some degree – even homemade vegetable soup, as raw ingredients have been prepared, mixed and cooked.
But leading experts increasingly think UPFs represent something different because the industrial processing changes the complex structure of nutrients in a food, and because they’re laden with additives and designed to make us eat more.
’According to the Nova system, corn on the cob would be classed as minimally processed; corn oil as a culinary ingredient; tinned sweetcorn as a processed food; and Doritos as a UPF,’ explains Dr Yanaina Chavez-Ugalde, a research fellow at City St George’s, University of London.
A common feature of UPFs is they tend to be almost universally high in fat, sugar and salt – and low in the vital nutrients our bodies need to function well, such as protein, fibre, good-quality fats, minerals and vitamins. 'It’s not just about what you are eating – it’s also about what you are not eating,’ says Dr Chavez-Ugalde.
Some scientists don’t think UPF is a helpful term – 'they think these foods are just a new name for an unhealthy diet,’ says Dr Samuel Dicken, a senior research fellow looking into UPFs at UCL, one of the main centres of UPF research.
But others are convinced the negative effect of UPFs on health is more complex. 'It’s clear something else is at play, beyond the nutrients contained in UPFs,’ says Dr Dicken.
This view was backed by a groundbreaking US study in 2019, by Dr Kevin Hall at the National Institutes of Health (the US body responsible for public health research), which showed that on a high-UPF diet, people ate on average 500 calories more a day.
Separately, there are concerns about the huge range of compounds being added to foods to increase their shelf-life, enhance appearance and taste, or make texture easier to consume.
But just because an ingredient has a chemical name on the label doesn’t make it 'bad’.
As Dr Dicken explains, many preservatives such as sorbic acid, used to inhibit microbial growth in cheese and wine, have been rigorously tested and are generally used in very small quantities.
’Preservatives aren’t really the problem – they’ve been used for a long time,’ says Dr Chris van Tulleken, author of the best-selling book, Ultra-Processed People.
Other compounds that have chemical-sounding names are in fact extracts of natural foods, says Dr Dicken. For example, curcumin often appears as E100 on food labels (the European Standards Food Agency requires all additives even natural foods to be given E numbers).
But there are concerns about ingredients such as artificial sweeteners. For instance, a large study by Harvard University last year linked these with an increased risk of cardiovascular problems, including heart attacks.
Three widely used sweeteners – sucralose, aspartame and acesulfame potassium – appear to be more problematic. One theory is artificial sweeteners cause inflammation that affects blood vessels and the balance of gut microbes.
Meanwhile, evidence suggests that emulsifiers used in processed food (e.g. ice cream) to improve texture and stability can contribute to a 'leaky gut’ in people with irritable bowel syndrome (IBS). A leaky gut means bacteria and toxins can leak into the bloodstream – triggering inflammation linked with chronic diseases.
But more research is urgently needed, says Dr Adrian Brown, a senior researcher in nutrition and dietetics at UCL, adding: 'Evidence currently links UPFs with serious health conditions, rather than identifying direct causes’.
And while there are concerns about individual additives, Dr Dicken thinks we should generally not see them as the main issue; rather they’re a 'useful indicator’ of other changes to the food.
For instance, pectin is a gelling agent used to 'hold ingredients together’ – an indication that food is made up of broken-down ingredients and likely to be soft, says Dr Dicken – which makes it easier to overeat.
And this is key to UPFs – manufacturers want us to eat more of their foods, so they design them to be irresistible: for instance, creating products with fats, sugar and salt in moreish ratios.
’This is a deliberate design process – which in turn can lead to weight gain and diseases related to obesity,’ says Dr Chavez-Ugalde, who was a food engineer before becoming so concerned by rising obesity that she changed careers.
Researchers also believe these industrial processes have a role to play in making UPFs potentially harmful to health.
One technique is extrusion moulding, which effectively turns raw ingredients into a soft pulp – 'almost like a mush of a product’, says Dr Chavez-Ugalde.
Pressed into smaller quantities, it’s used to make breadsticks, cereals and pasta. Such processes result in food that’s cost-effective and tasty, but isn’t very satisfying.
’The end result is food that is soft and energy dense, making it easier to over-consume because your body doesn’t register that it’s full soon enough,’ says Dr Dicken.
Why one 'serving’ is much smaller than you think
Food labels quote a mixture of values per 100g and per portion – but these are not always helpful, because what each of us considers to be a serving size can be very subjective. 'So 'portion’ can be a misleading term,’ says Alexandra Johnstone, a professor of nutrition, obesity and disease at the University of Aberdeen.
’Recommended serving sizes are often much smaller than what people typically consume, leading them to underestimate their true intake of calories, fats, sugar and salt.’
She cites the example of cereal packets, which quote nutritional values based on a 30g serving, 'but most adults or teenagers would pour themselves at least a 60g or 70g serving’.
Indeed, a Which? survey in 2023 found that when shoppers were asked to estimate how many servings popular foods contained they often got it wrong. More than a third thought a tube of Pringles contained two to four portions – when the packaging indicates it’s six to seven (around 13 crisps per person).
And more than half thought a 225g pack of halloumi would cover two to four servings – in fact the packaging says seven.
Meanwhile, larger packs, often presented as 'better value’ for money, may also be problematic, says Professor Johnstone.
’Research shows that bigger portions just encourage people to eat more due to 'unit bias’ – where we think a serving or pack is one portion, regardless of size,’ she says.
If you’re unsure, try measuring out a food yourself at home to see how what you consume compares with the front-of-packet labels.
6 ways to help detect UPFs
Buyer beware: There are no hard and fast rules about what makes a product a UPF, however here is a rough guide of the signs to look for (see main story and previous page for explanations):
- Contains ingredients you don’t expect to find in a domestic kitchen such as high-fructose corn syrup, hydrogenated oils and hydrolysed proteins, emulsifiers, sweeteners, thickeners, and glazing agents.
- Very high in calories, sugar, salt and/or fat (to make it irresistible).
- Very low in fat and sugar (will have additives to make up for loss of fat and sugar).
- Processed into a 'shape’ e.g. snack food, cereal.
- It contains more than five ingredients.
- Has a health claim on the packet.
Ingredients – and what they REALLY do
Reading the labels on food packaging can throw a new light on your shopping choices. For instance, this healthy-looking Light & Free Strawberry Greek Style Yogurt from Danone is low in fat and salt, and medium in sugar.
It also counts as a UPF, with ten additives – some are to improve the taste and texture to make up for removing the fat and sugar. The ingredients marked with * can be a sign that a food is a UPF.
Yogurt (milk).
Strawberry (12%).
Oligofructose (fibre): This is inulin, a type of fibre found in plants. Sweet-tasting, it’s often added to low-calorie and low-fat food products to enhance colour and texture.
*Potato starch: A fine white powder primarily used as a thickening agent. Its ability to absorb water makes it effective at creating a smooth texture without affecting flavour. While it doesn’t have an E number (it’s not chemically altered), it is commonly used as an additive.
*Tapioca starch: A carbohydrate extracted from the root of the cassava plant and often added as a thickening agent and to improve texture. It has a neutral taste, making it versatile for both sweet and savoury products. No E number, but used as an additive.
*Modified maize starch: Derived from corn starch, this has undergone physical and enzyme treatment to change its physical properties, so it can be used for thickening and emulsifying (to help liquids blend together) or gelling a food product together. It’s used in a variety of products including soups, dressings and baked goods.
This healthy-looking Light & Free Strawberry Greek Style Yogurt from Danone is low in fat and salt, and medium in sugar
*Stabilisers (pectin, carrageenan): These are used to maintain the structure, texture and consistency of food. Pectin (E440), found in citrus peel but also extracted from raw materials, helps ingredients stick and mix together and hold their consistency. Carrageenan (E407) is derived from red seaweed and widely used to thicken foods, including yogurts.
*Flavourings: Manufacturers don’t have to state which flavourings have been used as long as they meet regulatory food safety requirements.
*Acidity regulators – calcium citrate (E333), sodium citrate, (E331), lactic acid (E270): These are added to foods to adjust and maintain the levels of acidity and alkalinity – to inhibit the growth of harmful bacteria and extend a product’s shelf-life. They can also be used as emulsifiers, helping prevent ingredients in products such as jellies and dairy products separating.
Black carrot juice concentrate: Made from the juice of black carrots, this is often used as a natural food colouring.
*Sweeteners (acesulfame K or E950; sucralose E955).
Vitamin D: Often added to dairy products to enhance the absorption of calcium.
Even traffic light system on packaging isn’t foolproof
All packaged food must, by law, carry a label clearly detailing key nutritional information, says Dr Adrian Brown, a senior research fellow in nutrition and dietetics at University College London.
’This includes the amount of energy and the quantity of fat, saturated fat, carbohydrates, sugar, protein and salt contained in 100g/100ml.’
These are also quoted as a percentage of an adult’s daily requirements – but this is based on the needs of an average-sized woman, who needs 2,000 calories a day, so isn’t a useful guide for men (who need 2,500 calories on average) or children.
Labels must also give storage instructions, the shelf-life and state whether it contains any of 14 common allergens (e.g. nuts, dairy, wheat).
Many manufacturers also use a traffic-light system to grade levels of fat, sugar, salt and calories (this is only voluntary).
Green – means it has low levels per 100g (i.e. 3g or less of fat; 5g or less of sugar; 0.3g or less of salt).
Amber – medium levels per 100g (i.e. 3g-17.5g of fat; 5g-22.5g of sugar; 0.3g-1.5g of salt).
Red – high levels per 100g (i.e. over 17.5g fat; over 22.5g sugar; over 1.5g salt).
But a food could earn green or amber ratings, yet qualify as a UPF. This is because while it may be low in fat, sugar and salt, it also contains artificial additives and has been highly processed.
UPFs are designed to make them irresistible to consume using carefully calculated ratios of fat, sugar, salt and additives, says Dr Yanaina Chavez-Ugalde, a research fellow at City St George’s, University of London, who has previously worked in the food industry.
Labels also won’t tell you what manufacturing processes have been used. This could matter, as cooking meat at high industrial temperatures, for instance, can create chemicals linked to cancer.
From fish fingers to breakfast cereal, there could be a healthier choice…
Any regular shopper knows it’s impossible to avoid processed foods – yet for many of us, cooking everything from scratch is neither practical nor cost-effective. So what can you do if you need something that’s easy to prepare?
’UPFs are here to stay – and it’s important not to totally demonise them as so many people rely on these foods to feed their families,’ says Dr Yanaina Chavez-Ugalde, a research fellow at City St George’s, University of London. 'But it’s vital to understand them better so we can evaluate their use – and their harms – to all of us as shoppers.’
Food companies have become savvy in the way they describe additives – and often don’t use E numbers, which have negative connotations for many shoppers, preferring to use names instead.
And be wary of terms such as 'low fat’. By law in the UK, low fat means a product has less than 3g of fat per 100g. However, manufacturers often add flavourings, starch and sugar to make up for the lack of fat, improving their taste and texture. And some studies have shown that we eat more of a product if it has a low-fat label.
If you’re looking to cut down on UPFs use the label to guide you to a product that’s processed, rather than ultra-processed
Similarly with 'low sugar’: a food has to contain less than 5g of sugar per 100g to be labelled low sugar. But sugar is only one ingredient you need to keep an eye on – a product that claims to be low sugar could also be high in fat and calories. And foods claiming to have 'no added sugar’ can still contain several naturally-occurring sugars such as fruit juice, or sweeteners.
The term 'natural’ might make you think it’s a healthy, unprocessed food, but manufacturers are allowed to call a food 'natural’ if it’s made up of ingredients produced by nature originally.
This means foods that have undergone considerable processing can still be labelled as natural.
’As a rule of thumb, if you’re looking at a packaged food, it contains more than five ingredients and you’ve never heard of some of them or wouldn’t find them in your kitchen, then the chances are it’s a UPF,’ says Dr Adrian Brown, a senior researcher in nutrition and dietetics at UCL.
Another tip, if you’re looking to cut down on UPFs, is to use the label to guide you to a product that’s processed, rather than ultra-processed. You can check its credentials on the free website, openfoodfacts.org, which classifies foods according to traffic lights, Nutri-Score (the European equivalent of traffic lights) and Nova, (see previous page). Look for Nova 3 or lower (Nova 4 is UPF). Here are suggestions, based on listings on the website…
Pasta sauces: These often are based on cooked tomatoes, which contain lycopene (linked to eye health) as well as vitamins. A good one will count as one of your five-a-day. While some include additives and qualify as UPFs, others may simply be processed: for instance, you’d easily find the ingredients for Loyd Grossman’s tomato and basil sauce at home (though it does score amber for sugar, salt and fat).
Baked beans: A source of protein and fibre, the humble baked bean can be a good supper if you’re pressed for time, but many options count as UPF. A can of basic Heinz baked beans in tomato sauce counts as Nova 3 (but it does score amber on salt).
Fish fingers: Fish is a good source of protein. But many fish finger products are heavily processed using a list of additives. A better choice might be Birds Eye 10 Omega 3 (a Nova 3, but it still scores amber for fat and salt).
Cereals: These can be a minefield, with many containing high levels of different sugars as well as additives; they’re also highly processed. But some are less processed, qualifying as Nova 3, such as Weetabix..
Become a sugar detective…
On food labels sugar may be referred to as 'sugars’ or 'total sugar’, which includes both naturally occurring and added sugars. Added sugars means those included during the manufacturing process.
Often, added sugars may be listed under various names making them difficult to spot – but they are all essentially just sugar in disguise. Names to look out for include dextrose, fructose, glucose, lactose, maltose, sucrose, beet sugar, cane sugar, agave nectar, corn syrup, honey, maple syrup, molasses, barley malt, maltodextrin and rice syrup.
For instance, a Jaffa Cake contains five types of sugar: glucose-fructose syrup, sugar, dextrose, concentrated orange juice and glucose syrup. And Cheerios cereal contains four: sugar, invert sugar syrup, molasses and caramelised sugar syrup. This is all sugar and has the same negative effects on health if consumed excessively.
Simple swaps – and they’re still packed with flavour
We all need to eat, and our on-the-go lives mean that many of us rely heavily on packaged supermarket foods to put a meal on the table.
But spending a few moments looking at the food labels can help you to choose a less processed and potentially healthier option.
Here, nutritionist Rob Hobson, author of Unprocess Your Life, suggests some simple swaps to consider:
Cooked meat:
Swap: Premier Deli cooked ham, £2.75, Tesco
This contains 20 ingredients, including four types of sugar (sugar, dextrose, glucose syrup and caramelised sugar syrup) and additives. It also scores amber on the traffic light label system for fats/saturated fats, green for sugar and red for salt.
This contains 20 ingredients, including four types of sugar (sugar, dextrose, glucose syrup and caramelised sugar syrup) and additives
For: M&S British roast chicken slices, £3.80, ocado.co.uk
These simply prepared chicken slices contain just three ingredients that you would easily use yourself at home – chicken breast, salt and brown sugar. Nothing more. A much healthier option all round.
These simply prepared chicken slices contain just three ingredients that you would easily use yourself at home
Sliced cheese
Swap: Dairylea Cheese, 8 x 20.5g slices, £1.45, Sainsbury’s
Tempted to pop a slice of this in your lunchtime sandwich? This product has red ratings (for saturated fat and salt) and amber (for fat and sugar) and additives such as emulsifying salts, making it a highly processed option.
This product has red ratings (for saturated fat and salt) and amber (for fat and sugar)
For: Sainsbury’s Gouda Cheese, 10 slices, £2.80
There is nothing but cheese (made from cow’s milk) in this more minimally-processed sliced cheese. It’s high in fat but this simple swap also offers you and your family a much better way of getting a good source of calcium into your diet.
There is nothing but cheese (made from cow’s milk) in this more minimally-processed sliced cheese
Crisps
Swap: Pringles Original 185g, £2.25, Sainsbury’s
These highly processed snacks don’t contain real potato as you know it – it’s dehydrated potato, a highly processed derivative that’s been altered in structure and nutritional profile. The additives and processing not only make this product moreish but also softer, which helps explain why you can’t stop at eating just one.
These highly processed snacks don’t contain real potato as you know it – it’s dehydrated potato
For: Tyrrells Naked (Unsalted) Crisps 150g, £1.75, Waitrose
These are just potato and sunflower oil, which are two ingredients you will find in your kitchen at home. You could even make crisps like these yourself! They’re still high in fat – and you need to stick to the portion size, as they’re not considered a healthy snack.
These are just potato and sunflower oil, which are two ingredients you will find in your kitchen at home
Crackers
Swap: Ritz Crackers Original, £1.25, Tesco
Made using ten ingredients – including palm oil (high in saturated fat). There are also two types of sugar (sugar and glucose-fructose syrup) which feature high up on the ingredients list. All in all, a highly processed cracker.
Ritz crackers are made using ten ingredients – including palm oil (high in saturated fat)
For: Nairn’s Super Seeded Oatcake, £1.60, Tesco
Contains fewer ingredients – eight compared with ten for the Ritz crackers – but they are predominantly organic whole foods, including oats and a good variety of seeds (sunflower, chia and flaxseed). With one exception (sustainable palm fruit oil), they’re all things you might find in your kitchen.
Nairn’s contains fewer ingredients – eight compared with ten for the Ritz crackers – but they are predominantly organic whole foods
We need proper label warnings to show what we are eating
Comment by Dr Chris Van Tulleken
Until five years ago, I had never read an ingredients list. Now it is the first thing I look at. So what changed?
In 2020 a colleague, TV producer Lizzie Bolton, urged me to read two papers – one had been published in an obscure Brazilian public health journal ten years earlier, about a new system for classifying foods according to how they were processed. The other was a dietary experiment about weight gain.
At first glance they didn’t seem particularly appealing and they sat in a pile on my desk for weeks. But they would turn out to be two of the most important papers I’ve ever read.
They were the seminal works on ultra-processed foods, or UPFs – these are industrially produced foods, from obvious junk to stuff that is sold as being healthy.
In fact, a good rule of thumb is that if there’s a health claim on the box it’s probably UPF.
So how can you tell if a food is ultra-processed? The definition, set out in the Brazilian paper, is useful for research but not for the average shopper.
So another rule of thumb is that if you look at the ingredients list and see an additive you don’t expect to find in a domestic kitchen, then it’s probably UPF.
This includes 'cosmetic’ additives – colours, flavours (even natural ones), emulsifiers, stabilisers – with no purpose other than disguising the fact the food is low quality.
The main problem with UPFs, as a recent analysis by my research group at University College London shows, is that they’re almost all very high in calories, sugar, salt and/or fat
The problem is that UPFs are engineered to be irresistible (the title of a BBC documentary I’ve just made about this, which is on iPlayer now).
Teams of scientists use brain scanners to 'hack’ our desires and produce foods that target our brain’s reward systems, so we can’t stop eating them. The additives help reduce cost or make you eat more – or both.
But the main problem with UPFs, as a recent analysis by my research group at University College London shows, is that they’re almost all very high in calories, sugar, salt and/or fat.
It’s not all equally bad. Supermarket wholegrain bread – yes, UPF – is better than a Creme egg. But there really is no such thing as healthy UPF. That wholegrain bread will be high in sugar, salt and calories.
This means that when you eat too much (which you will because that’s how it’s been designed), you gain weight – and you suffer the harms of an excess of the sugar (types 2 diabetes and tooth decay); salt (heart attacks and strokes); and saturated fat (more heart attacks and strokes).
I’ve spoken to development teams at many of the firms you buy from. They’re now trying to take out the additives, so you won’t think a product is a UPF.
This is already the case with many ready meals, fish fingers, breads and baked beans. When the team in Brazil were developing the definition, they never reckoned on the skills of these food scientists in making high-fat, high-salt, high-sugar products that would be addictive and cheap … but with no additives. So you need to be aware of the 'almost UPF’, too.
In our analysis we found that most of the merely 'processed’ products (rather than 'ultra-processed’) were also high in salt, sugar and fat.
And you can’t rely on the traffic lights for scoring foods, as these are voluntary and levels of salt, fat and sugar have to be far higher than the recommended maximum before a product even gets an amber light, let alone a red.
The food firms’ primary purpose is profit; it guides everything. Fine – it makes them no different from any other company. But it means we need the Government to step in to put proper warnings on UPFs and processed food, so we actually know what we’re eating.
What can you do now if you want to limit your intake? If you have the time and money, then cooking yourself, using fresh fruit and vegetables along with whole foods is strongly linked to good health.
And until the Government does step in, we’re left with trying to decipher food labels.
