Warnings to avoid ultra-processed foods (UPFs) could lead to some people eating even less healthily, researchers have said.
Two experts from the universities of Aberdeen and Liverpool argued research around UPFs is still in its infancy and more needs to be known before people are told to stop consuming them.
Instead, they said the focus of public health guidance should remain on eating a diet full of fruit, vegetables and wholegrains, while also limiting foods high in fat, sugar and salt.
UPFs have been linked in studies to poor health, such as an increased risk of obesity, heart disease, cancer and early death.
Examples of UPFs include ice cream, processed meats, crisps, mass-produced bread, some breakfast cereals, biscuits and fizzy drinks.
These UPFs also tend to include additives and ingredients that are not used when people cook from scratch, such as preservatives, emulsifiers and artificial colours and flavours.
However, some experts say it is 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.
In the new article, published in PLOS Medicine, experts 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, one of the authors of the article, 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.”
The article states there is a potential “social cost for many people with more limited resources” of removing convenient options and the possible negative mental health impacts on “those who worry about their health or live with eating disorders, particularly if social circumstances make avoiding UPFs difficult”.
It continued that “avoiding some types of UPFs” could lead some people to choose alternatives “that are higher in energy or macronutrients of concern.
“We know with certainty that foods which are energy dense and/or high in saturated fat, salt or sugar are detrimental to health and we should continue to advise consumers to limit consumption of these foods.
Professor Alexandra Johnstone, from the Rowett Institute of Nutrition and Health, University of Aberdeen and one of the authors, 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 and 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.”
In the paper, the authors published details of anything that could be seen as a competing interest.
Prof Johnstone said she currently receives funding from places such as UK Research and Innovation, charities and the Scottish Government, and leads an FIO Food research project “where there is a retailer project partner” looking at obesity.
“I also lead the DIO Food project, also funded by UKRI, with other UK retailers involved in data analysis and consumer trend reporting around HFSS purchase patterns.”
Prof Robinson said during 2014-2016, he was a named investigator on a project funded by Unilever and a project funded by the American Beverage Association.
He added: “I do not receive any financial awards or fees from the food industry.”
Dr Hilda Mulrooney, reader in nutrition and health at London Metropolitan University, said: “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 (e.g. breakfast cereals, breads) make substantial contributions to nutrient intakes in the UK population.”
