They have been linked to a range of deadly illnesses like heart disease, cancer and dementia – but experts say not all ultra-processed foods are bad.
Researchers say wholegrain breakfast cereals like Bran Flakes, plant-based milk and yoghurt and even supermarket bread can all be part of a healthy diet.
Ultra-processed foods, also known as UPFs, are mass-produced items like snacks, packaged bread and ready meals, many of which contain high levels of fat, sugar and salt.
They are also often packed with artificial ingredients, which experts say could have a detrimental impact on the healthy bugs in our gut that protect us from disease.
But experts say the new findings – presented at an annual meeting of nutrition experts in Maryland – show that processed foods are ‘not inherently harmful’.
The study team analysed data from more than 200,000 US adults to examine how diet quality affected the risk of heart disease, type 2 diabetes and premature death.
They found that the overall quality of a person’s diet mattered far more than how processed their food was.
However, that does not mean all UPFs are healthy.
Researchers have found that foods such as wholegrain breakfast cereals, plant-based milk, plant-based yoghurt, wholegrain bread and canned fruit can all be part of a healthy diet
Fast-food meals, chips, fizzy drinks, packaged desserts and snack foods such as crisps and chocolate bars remain poor choices, they warned.
They also stressed that minimally processed foods can be unhealthy choices.
Examples include white rice, fruit juice and homemade desserts made with refined flour and sugar.
Experts say the findings show that the public ‘should focus on what they’re eating overall, not just whether it’s processed’.
Commenting on the findings, Xiaowen Wang, a research fellow at Harvard T.H. Chan School of Public Health, said: ‘While many ultra-processed foods tend to be of poor nutritional quality and should generally be limited or avoided, processing itself is not inherently harmful.’
For their research, the team looked to separate the overall quality of a diet from the level of food processing.
They examined the plant-based part of each person’s diet over the course of 40 years, looking at how healthy those foods were and how processed they were.
Although the study included everyone – not just vegetarians and vegans – the analysis focused on plant foods so the researchers could make fair comparisons.
Around half of the people developed heart disease or type 2 diabetes or died over the course of the study, which ran between the 1980s and early 2020s.
The team found that those who ate healthier diets were much less likely to experience these outcomes than those with poorer-quality diets.
And crucially, the researchers found it made little difference whether those healthy diets were made up of ultra-processed or minimally processed foods.
They say this suggests the nutritional quality of food matters more than how processed it is.
A widely used system for classifying foods by the level of processing, known as Nova, does not take into account their nutritional value.
This means some nutritious foods are labelled as ultra-processed, while some minimally processed foods can still be high in sugar and provide little nutritional benefit.
Ms Wang said: ‘Advising people to universally avoid ultra-processed foods can lead to lower diet quality since healthy ultra-processed foods are beneficial and unhealthy minimally-processed foods are detrimental.
‘People should prioritize the quality of foods rather than focusing solely on the level of processing. Aim for more nutrient-dense, high-quality foods to help lower your risk of chronic diseases.’
