You might be eating ultra-processed foods every day — and not even know it.
From “healthy” snack bars to plant-based burgers, ultra-processed foods are everywhere, cleverly disguised as convenient and nutritious, says James Witts.
But growing research links them to serious health risks — so, how much is too much? And are meat-free alternatives any better?
Here's what the science really says.
What are ultra-processed foods?
We’ll come onto that in shortly. First, it’s relevant to explain exactly what ultra-processed foods are. What super-sizes them beyond simple processed foods? “When we talk about ultra-processed foods, we refer to the classification established by the NOVA scale,” says Romain Barres, professor of metabolic epigenetics and director of research at the University of Copenhagen.
“Ultra-processed are NOVA4 foods and are industrial-based products. They often contain a long list of ingredients – more than five – of which some you simply can’t find in a conventional kitchen. It’s important to stress that ultra-processed foods are different from processed foods (NOVA3 category), which are foods that are made at home or in a restaurant setting.”
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The NOVA scale classifies foods according to the degree of processing, not nutrient content. NOVA1 features unprocessed or minimally processed foods like fresh fruit and veg; NOVA2 is processed culinary ingredients. Think sugar, honey and salt; NOVA3 we’re talking canned veg and cheese; NOVA4 soft drinks, processed meats and many sports nutrition products such as protein bars – seen recently in the Channel 4 documentary ‘Licensed to Kill’ where fitness coach Joe Wicks and Professor Chris van Tulleken created a protein bar packed with ‘harmful’ ingredients.
Are ultra-processed foods really bad for you?
A swathe of evidence links high ultra-processed food uptake with bad health. Most recently, a review of 41 studies presented at the American College of Cardiology annual scientific meeting in Asia revealed that ultra-processed food led to heightened risks of hypertension, cardiovascular disease, cancer, metabolic diseases and depression. A study by Barres himself revealed it could also harm your chances of having a baby.
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“We showed that the consumption of ultra-processed food is associated with a lowering of motile sperm cells,” he says. “This was linked to a reduction of the sex hormones FSH [follicle-stimulating hormone) and testosterone. This is concerning as sperm quality has decreased over the past few decades alongside an increase in ultra-processed foods. We suggest those looking to conceive should avoid the consumption of ultra-processed food where possible.”
There was further concern with how the foods were packaged with Barres and his team discovering plastic in the blood and semen of the participants. “We’re unsure of the origin of the phthalates [pronounced ‘thal-ates’; the name for a group of synthetic chemicals added to plastic to make them flexible and transparent] that we found in excess in the blood and semen of participants after ultra-processed food consumption. It’s possible that they derived from the handling of many ingredients transported into plastics therefore introducing a contamination during the industrial process.”
Barres can’t confirm for certain that those phthalates emanated from ultra-processed packaging. But there’s no doubt that microplastics are increasingly inhabiting our bodies and minds with one study estimating that our cerebral organs alone may contain 5g of the stuff or roughly a teaspoon. A team from the University of Graz in Austria suspect these particles with our gut microbiome to the detriment of our health.
Why do we buy ultra-processed foods?
So, why oh why are we attracted to ultra-processed foods to the extent that its estimated global market size in 2024 nestled at $1.2-trillion. “They’re made to be highly attractive and palatable,” says Dr Samuel Dicken, research fellow at the department of behavioural science and health at University College London. Which is why ultra-processed foods comprise many that might surprise. “That includes ‘healthy’ breakfast cereals, snack bars, and even flavoured yoghurts and some breads.” ‘Healthy’ flavoured water, pre-cooked rice, plant-based milks, flavoured cottage cheese and cheese slices are also on the ultra-processed list.
As are foods that make much of being a healthier alternative to meat. We’re talking processed vegetarian burgers, sausages and those fake chicken nuggets gathering icy dust in the bottom of your freezer. They’re all classified in NOVA4 because they contain additives such as flavour enhancers, stabilisers and colourants. Protein, from soy or wheat, is also extracted and reconstituted. That’s another hallmark of ultra-processed foods.
Dicken says the one glimmer of healthy light is that these vegetarian alternatives are unlikely to be as bad for you as animal-based ultra-processed foods. But, in an ideal world, both shouldn’t be eaten regularly.
If you do, Dicken’s research suggests you’ll lose more weight. “We compared ultra-processed food and minimally processed food diets in ‘real wrld’ conditions,” he says. “One group started with an eight-week diet of minimally processed food, such as overnight oats or homemade spaghetti bolognese. After a four-week ‘washout’ period during which participants went back to their normal diet, they switched to a diet of ultra-processed foods, such as breakfast oat bars and a lasagne-ready meal. The other group completed the diets in the opposite order. In total, 50 participants completed at least one diet.”
After eight weeks on each diet, both groups lost weight, rather worryingly likely as a result of the improved nutritional profile of what they were eating compared to their normal diet. However, this effect was higher (2.06% bodyweight drop) on the minimally processed diet compared to the ultra-processed diet (1.05% drop).Potential reasons for the difference include energy density,” says Dicken. “Our previous study showed ‘healthy’ ultra-processed foods are more energy dense than healthy minimally processed foods.”
Ultimately, Dicken advises sticking as closely to nutritional guidelines as you can by moderating overall energy intake; limiting salt, sugar and saturated fat; and choosing less processed options such as whole foods and cooking from scratch.