Fears over ultra-processed foods (UPFs) 'could mean people eat even less healthily', researchers have warned.
In recent years UPFs – which are usually high in salt, sugar and saturated fat – have been linked in studies to an increased risk of obesity, heart disease, cancer and early death.
Examples can include biscuits, ice cream, processed meats, crisps, mass-produced bread, fizzy drinks and some breakfast cereals.
However, two experts have argued that research around UPFs is still in its infancy and more needs to be known before people are told to stop consuming them.
They also warned that a number of UPFs – such as baked beans, vegetable-based pasta sauces and some soups – are actually very nutritious and can contribute to a healthy diet.
The scientists, from the universities of Aberdeen and Liverpool, said the focus of public health guidance should remain on eating a diet full of fruit, vegetables and wholegrains while limiting foods high in fat, sugar and salt.
In the new article, published in the journal PLOS Medicine, they argued that less well-off people could be most affected by any blanket health warnings about UPFs without more scientific evidence.
Professor Eric Robinson of the University of Liverpool said: 'Foods classed as ultra-processed which are high in fat, salt and/or sugar should be avoided, but a number of ultra-processed foods are not.
'We should be thinking very carefully about what advice is being given to the public, as opposed to providing simplified and potentially misleading messages that grab headlines.'
Overall, UPFs tend to include additives and ingredients that are not used when people cook from scratch such as preservatives, emulsifiers and artificial colours and flavours.
Some experts say it's not clear why UPFs are linked to poor health and question whether this is because of processing, additives or because people tend to eat less nutritious other foods.
The article states there is a potential 'social cost for many people with more limited resources' of removing convenient options.
Meanwhile there could be negative mental health impacts on 'those who worry about their health or live with eating disorders, particularly if social circumstances make avoiding UPFs difficult'.
Professor Alexandra Johnstone, from the University of Aberdeen said: 'We must guard against the possibility that the people in our society who are already most at risk of not being able to afford to eat healthily are not put in an even worse position as we continue to investigate the links between some ultra-processed foods and poor health.
'We need more high-quality mechanistic research in humans, using controlled diets, to tease out the effects of nutrient profile and ultra-processing per se.'
The article concluded: 'Based on the balance of current evidence, we do not believe it is appropriate to be advising consumers to avoid all UPFs.
'We await further evidence to inform consumer guidance on the need to limit consumption of specifics foods based on their degree or type of processing.'
Commenting on the study Dr Hilda Mulrooney, reader in nutrition and health at London Metropolitan University, added: 'This is an important and timely paper, given the current level of interest in UPFs and their potential effects on health.
'It is important to acknowledge the fact that, for some groups in particular, foods classed as UPFs make very significant contributions to nutrient intakes, and these would be difficult to achieve otherwise.
'Much of the research available shows associations between UPFs and health outcomes and cannot demonstrate causality.
'This distinction is important, given that many UPFs — for example breakfast cereals and breads — make substantial contributions to nutrient intakes in the UK population.'
