It seems like only yesterday we could enjoy our toast in the morning without a care in the world. Not anymore. According to new research some ultra-processed foods (UPFs) can deliver the same effect as drugs such as nicotine and alcohol, with experts now recommending that many UPFs products be officially labelled “addictive”. 

A global analysis of 281 studies from 36 countries, published in The British Medical Journal (BMJ), found that the way some people eat UPFs could “meet the criteria for diagnosis of substance use disorder”. The team of international researchers also found that “ultra-processed food addiction” is estimated to occur in one in seven adults and one in eight in children, causing behaviours such as withdrawal symptoms, intense cravings and continued consumption despite obesity, binge eating and other health problems. 

So today, that slice of packaged supermarket loaf is more than likely a dietary devil than a time-saving treat. And thanks to Dr Chris van Tulleken, author of the bestselling book Ultra-Processed People: The Science Behind Food That Isn’t Food, it’s a term now popping up everywhere. 

Despite the latest research, this is an area beset by contradictions and confusion, with many of us wondering what exactly constitutes an UPF and if there’s anything left to eat that won’t make us fat or unwell.

Recently, a team of researchers and government advisors suggested that some UPFs have been unfairly demonised and can, in fact,  be good for you after all. 

At the briefing, organised by the Science Media Centre, the scientists said it was often the salt, sugar and fat content that was harmful rather than the processing itself and that consumers should instead consider each food on its own merits. They argued that bread and breakfast cereals, which are often fortified with vitamins and minerals, can play a part in a healthy diet and warned that many poorer families did not have the luxury of being able to buy “artisanal bread”.

Prof Robin May, chief scientific adviser at the Food Standards Agency, said: “It’s really important that we don’t throw the baby out with the bath water.”

That said, most scientists agree that the worst types of UPF are largely to blame for our skyrocketing obesity rates and the problem with so many UPFs is that they can be impossible to resist.

“It’s high-fat, high-salt and high-sugar, but these ingredients have been combined into industrial products with exotic additives, which can’t really be described as food. They’re ultra-processed foods, a set of edible substances that are addictive for many and which are now linked to weight gain, early death and, yes – depression,” Dr van Tulleken told the Telegraph.

So which foods should remain on the “naughty list”, to be eaten on rare occasions and which can be part of a healthy diet?

What is the definition of ultra-processed food?

UPFs now account for almost 60 per cent of the UK diet, and it’s easy to see why the products are popular; they’re cheap, convenient, delicious and designed to be moreish. 

Almost all food is processed to some extent, to make it digestible and tasty, or to delay spoiling. Think flour (made from ground and sifted grains), tinned tomatoes (sealed in a can using heat) and pasta (produced by mixing flour, water and sometimes eggs). 

UPFs are different. The term dates to 2009 when Carlos Monteirom, a professor from the University of São Paulo in Brazil, developed the Nova classification system. This divides food into four groups according to how extensively they have been processed, ranging from group 1, foods that are minimally processed with no added salt, sugar, oils, fats or other additives,  to group 4, which are ultra-processed foods that are formulated in factories, often using multiple processes. Scientists around the world now use the Nova system to study links between eating habits and disease, and evidence is mounting that UPFs can seriously damage our health.

Typical examples in our daily shop include pizzas, breakfast cereals and cereal bars, cakes and biscuits, sweet and savoury snacks, crisps, baked goods like bread, sausage rolls and pastries, ready meals, flavoured yoghurt and yoghurt drinks, fruit drinks, milk drinks, alternative milks and alternative meat products. 

Most of these are obviously UPF and clearly not good for our health;  they’re loaded with sugar, salt and/or fat. Additives are a red flag, too. “If there’s an ingredient on the list that you don’t find in a kitchen cupboard, it’s very probably UPF,” says Dr van Tulleken. 

Some UPFs are harder to identify. “Anything with a health claim on it is probably a UPF,” Dr Van Tulleken says. “It’s marketing by companies that have the budget to do it. There’s no health claim on broccoli, oily fish or any of the stuff we know is healthy.” 

For example, the wording on the packet about fibre, vitamins and/or minerals suggests the food has been stripped of nutrients during processing and the manufacturer has added some back in order to be allowed to promote it as healthy. These types of health claims are common on boxes of breakfast cereal, for example.

It’s worth noting that some unfamiliar ingredients don’t necessarily signify UPF. Certain flours sold in the UK are fortified with calcium, iron, thiamine and niacin, and don’t count as UPF.  Corn starch, also known as corn flour, isn’t UPF either, but “modified” corn starch is.

What’s the difference between processed food and ultra-processed food?

Distinguishing unprocessed food (like an apple) from UPF (a chocolate bar) is easy, but the difference between processed and ultra-processed food is not always clear.

In his guide, ‘Ultra-processed foods: what they are and how to identify them’, Prof Monteiro lists the ingredients to look out for that indicate a product is probably UPF. 

Check for: sugars (fructose, high-fructose corn syrup, “fruit juice concentrate”, invert sugar, maltodextrin, dextrose, lactose);  modified oils (hydrogenated or interesterified oils); and protein sources (hydrolysed proteins, soya protein isolate, gluten, casein, whey protein and “mechanically separated meat”). These will be found at the beginning or in the middle of the ingredients list of UPF.

Cosmetic additives are designed to enhance the flavour, appearance and texture of food and are found at the bottom of the ingredients list. They include flavours, flavour enhancers, colours, emulsifiers, emulsifying salts, sweeteners, thickeners, and anti-foaming, bulking, carbonating, foaming, gelling and glazing agents.

What alternatives are there to ultra-processed foods?

Preparing meals and snacks from scratch with unprocessed or minimally processed ingredients is ideal, but for most of us this simply isn’t possible all the time. The good news is there are non-UPF versions of many UPFs – these products are processed rather than ultra-processed. 

Many organic versions of common UPFs, such as tins of baked beans and non-dairy milk alternatives, are not ultra-processed.  For example, most ready-meal lasagne is an UPF but Tesco and Marks & Spencer both sell versions that are processed but not ultra-processed, and both score B  for “good nutritional quality”.  

Dr van Tulleken stresses he’s not encouraging anyone to eat ready meals every night just because they’re not ultra-processed.  “There are lots of non-UPF ready meals that are great and convenient, but the evidence shows that if you can possibly cook a lasagne at home, it will be better for you than even the non-UPF convenience meal.”

Dr van Tulleken also recommends Open Food Facts, a free app and online database that makes it easy to differentiate processed from UPF products. UPF is identified as Nova group 4, while processed food is Nova group 3. The database also indicates how nutritious a product is according to the Nutri Score system, a five-point scale that rates food letters from A to E, indicating highest to lowest nutritional quality, and colours from green to red (best to worst).

Why are ultra-processed foods bad for you? 

Numerous studies have linked UPFs with a range of health problems, including obesity, diabetes, cancer and dementia. Most recently, studies from Australia and China suggested UPF can significantly raise the risk of high blood pressure, heart disease, heart attacks and strokes. 

The Australian research followed more than 10,000 women for 15 years and found those who consumed the most UPF were 39 per cent more likely to develop high blood pressure than those who consumed the least. High blood pressure is linked to heart disease, disease of the arteries and dementia.

The Chinese research involved more than 325,000 men and women and linked high UPF consumption with a 24 per cent higher chance of problems like heart attack, stroke and angina.  

There is also evidence linking UPF to obesity. It’s thought the soft/creamy texture and intense flavour of many UPFs makes them “hyper palatable”. This confuses the signals between the gut and the brain; we can’t tell when we’re full , so we eat more.

Do ultra-processed foods cause cancer? 

Earlier this year, the results of a large study by Imperial College London were published in The Lancet medical journal. 

The research, the largest of its kind, involved almost 200,000 UK adults and linked higher consumption of UPF to increased risk of cancer, specifically ovarian and brain cancers.

It’s not clear why UPF seems to be causing us harm. Research suggests it’s not just the high levels of sugar, fat and salt found in UPFs that are the problem, or the additives on their own. “The individual ingredients of UPF may each be harmful, but it is in combination that they do the most harm,” Dr van Tulleken says. The effect of individual molecules on our metabolism is complex, so scientists are still trying to work out exactly how this works.

Some scientists are cautious about studies that suggest UPFs are at the root of disease. They argue most of the research is observational and therefore doesn’t prove that UPF actually causes health problems.  Researchers can adjust results to take into account some but not all of the many lifestyle factors that might influence the results, such as smoking, exercise, sleep and stress.  

But Dr Scott believes there’s now sufficient evidence to ring alarm bells. “Every study about UPF, as far as I know, has shown a negative impact on health,” she says. “If you combine the consistency of that evidence with what we know about the health benefits of minimally processed food, it means it’s time to start thinking about how we can reduce UPFs in our shops and also in our shopping baskets.”

Which ultra-processed foods should I avoid?

It’s impossible to rank UPFs precisely from least worst to worst for your health – there are too many factors involved.

Some nutritionists suggest that if you do buy UPF, check the label and choose one low in sugar, fat and salt. Try to add lots of good stuff to your plate – for example eat lots of leafy greens with a UPF pizza. Or if you have a UPF meal for dinner, try to eat minimally processed food for the rest of the day.

Similarly, if you have a bacon sandwich for breakfast, opt for a UPF-free dinner with plenty of vegetables.

Processed meat – any that’s been preserved or changed including bacon – is associated with a higher risk of bowel cancer. According to Cancer Research UK, just 25g a day (that’s one measly rasher) raises your risk. Eating large quantities of red meat has been associated with it too. 

When it comes to bacon, the blame is laid with chemicals added in the processing: nitrates and nitrites.

“It’s about doing what you can where you can because we all have to navigate everyday life,” Dr Scott says. “Focus wherever possible on minimally processed food. And I know this is impossible for a lot of people, but wherever possible, cooking those foods yourself so you know exactly what’s gone into them.”

Dr Scott and Dr van Tulleken believe it shouldn’t be up to individual consumers to navigate UPFs on their own. Our supermarkets and high streets are overflowing with UPFs made by food manufacturers who invest significant amounts of money into trying to convince us to buy their products.

“I would like there to be a public health campaign warning people about the research on UPFs, which is very robust, “ Dr van Tulleken says. “UPFs should eventually have warning labels, and our national nutrition guidance should advise people to cut down.”

He isn’t calling for everyone to give up UPF completely. “My interest is in people having more choice and freedom, not telling people what to eat,” he says. “But if 60 per cent of your calories are coming from UPFs, the evidence shows that those products are troubling and are not made with your health in mind.”