We all know that ultra-processed foods are bad for us, but what ingredients should we particularly try to avoid? And what are they doing to our bodies?
Ultra-processed foods (UPFs) might taste good and provide an easy hunger fix, but their long-term health consequences are starting to scare nutrition experts.
By Holly McHugh
These foods are often high in added sugars, salt and saturated fats, while being low in protein, fibre and essential micronutrients – making them energy dense and nutritionally poor. They also frequently contain a cocktail of additives to improve taste, texture, colour and shelf life.
We’re talking foods like fizzy drinks, packaged biscuits and cakes, breakfast cereals, mass-produced bread, ready meals, flavoured yoghurts, processed meats and some fast food.
Now, eating some UPFs as part of an otherwise healthy diet is okay. Life wouldn’t be as good without bacon, biscuits and burgers after all.
There’s also no denying that processed foods are useful for those short on time and cash – two things most of us never seem to have enough of. But problems arise when the occasional treat turns into an everyday staple.
Regularly eating large amounts of UPFs has been linked to a plethora of diseases. And, rather concerningly, the largest world review to date recently found that UPFs are linked to harm in every major organ system in the body.
Which makes it pretty alarming that, in both the UK and the US, more than half of the average diet is made up of UPFs.
While most of us know that UPFs aren’t great for our health, spotting them isn’t always easy. Plenty of everyday foods that seem harmless are hiding overly-processed ingredients that may be bad for us.
So, to help you make more informed choices, here’s our guide to the archvillains – the ingredients you should really try to limit or avoid if you’re putting your health first.
1. Artificial Colourings
A large amount of research has linked particular food dyes to behavioural effects in children - Image credit: Getty Images
Artificial colourings are lab-made chemical dyes added to foods to enhance or replace colour lost during processing.
Three that raise the biggest red flags are:
- Tartrazine (E102 / FD&C Yellow 5)
- Sunset Yellow (E110 / FD&C Yellow 6)
- Allura Red (E129 / FD&C Red 40)
These dyes are used in sweets, fizzy drinks, desserts and breakfast cereals.
They also sneak into less obvious foods like sauces, cheeses and vegan meat alternatives, where they’re used to give a more meat-like colour.
These dyes are best known for their links to behavioural effects in children. A large amount of research has connected them to hyperactivity, difficulty concentrating and mood changes in some kids, and they may worsen ADHD symptoms.
2. Nitrates And Nitrites
Nitrites and nitrates are commonly added to processed meat such as bacon, sausages, ham and deli meats - Image credit: Getty Images
These preservatives are commonly added to processed meats such as bacon, sausages, ham and deli meats to extend shelf life and give meat its familiar pink colour and cured flavour.
In the acidic environment of the stomach, these compounds can form nitrosamines – substances linked to an increased risk of bowel cancer.
In 2015, the World Health Organization’s International Agency for Research on Cancer declared processed meat carcinogenic.
More recent studies have linked higher intakes of nitrates and nitrites to:
- cancer
- type 2 diabetes
- and increased metabolic risk.
3. Emulsifiers
You'll find carboxymethylcellulose and polysorbate-80 in mass-produced breads, ready meals, frozen pizzas, burgers and sweets - Image credit: Getty Images
Emulsifiers are one of the most common additives in processed foods.
Two repeatedly linked to health concerns are:
- carboxymethylcellulose
- polysorbate-80
These are found in:
- ready meals
- frozen pizzas
- burgers
- breads
- sweets
- sauces
- and processed snacks.
Researchers are increasingly concerned about how they affect the gut microbiome.
Studies suggest they may:
- promote gut inflammation
- contribute to obesity
- increase metabolic syndrome risk
- and raise the likelihood of inflammatory bowel disease.
4. Interesterified Palm Oil
Most people have no idea how much they're eating - Image credit: Getty Images
Interesterified palm oil is commonly used in:
- margarines
- spreads
- pastries
- cakes
- biscuits
- chocolate
- and dairy alternatives.
The concern comes from the chemical rearrangement process used to modify the fat molecules.
Studies suggest these engineered fats may increase spikes in blood fats after meals and potentially increase long-term heart disease risk.
One major problem is that labels often simply list:
without revealing whether it has been interesterified.
5. High-Fructose Corn Syrup
A large body of research links high HFCS intake to obesity, diabetes and heart disease - Image credit: Getty Images
High-fructose corn syrup (HFCS) is widely used in processed foods and drinks, especially in the United States.
It appears in:
- fizzy drinks
- cereals
- yoghurts
- sweets
- bread
- soups
- and sauces.
Unlike glucose, fructose is processed by the liver, where excess intake is more likely to be converted into fat.
Research links high HFCS intake to:
- fatty liver disease
- insulin resistance
- obesity
- type 2 diabetes
- heart disease
- and gut microbiome disruption.
The Cocktail Effect
Another growing concern is what researchers call the “cocktail effect.”
Food additives are usually tested individually by regulators, but in real life people consume multiple additives together every day through ultra-processed foods.
Recent studies suggest combinations of additives may have effects that individual testing fails to detect.
Researchers found that people with higher exposure to common additive mixtures were more likely to develop type 2 diabetes, even after accounting for overall diet quality and lifestyle factors.
Experimental studies on:
- gut cells
- liver cells
- and brain cells
also found effects from additive mixtures that could not be explained by individual additives alone.
Think Before You Chew
Experts say completely avoiding ultra-processed foods is unrealistic for most people.
But understanding what is inside them may help reduce long-term health risks.
As a general rule:
- shorter ingredient lists are usually better
- fresh or minimally processed foods are preferable
- and heavily engineered foods are best treated as occasional indulgences rather than daily staples.