Action is now needed to reduce the use of ultra-processed foods (UPF) in diets around the world due to their health risks, international experts say in a global review of research.
They say the way we eat is changing—from fresh, whole foods to cheap, highly processed foods—which increases the risk of developing a range of chronic diseases, including obesity and depression.
Writing in The LancetResearchers say governments need to “step up” and introduce warnings and higher taxes on UPF products to help fund access to more nutritious foods.
However, some scientists say this review cannot prove that UPFs directly cause health harm, and more research and testing is needed to prove this.
Ultra-processed foods are defined as containing more than five ingredients that you won't find in your kitchen cupboard at home, such as emulsifiers, preservatives, additives, colors and sweeteners.
Examples of UPF include sausages, chips, baked goods, cookies, instant soups, sodas, ice cream and supermarket bread.
Research shows that these industrially produced foods are increasingly found in diets around the world, degrading the quality of what we eat through too much sugar and unhealthy fats, and not enough fiber and protein.
This review of evidence on the health effects of UPF, conducted by 43 global experts and based on 104 long-term studies, suggests that these products are associated with an increased risk of developing 12 diseases.
These include type 2 diabetes, cardiovascular disease, kidney disease, depression and premature death from any cause.
Review author Professor Carlos Monteiro from the University of Sao Paulo in Brazil, who created the Nova classification system for classifying food, said the growing consumption of ultra-processed foods is “changing diets around the world, displacing fresh and minimally processed foods and dishes.”
“These changes in what people eat are fueled by powerful global corporations that make huge profits by prioritizing ultra-processed foods, supported by extensive marketing and political lobbying to stop effective public health policies that promote healthy eating,” he added.
Co-author Dr Philip Baker from the University of Sydney said the answer was a “strong global public health response, such as a coordinated effort to combat the tobacco industry”.
The review acknowledges the lack of clinical trials showing exactly how UPF harms health, but says this should not delay action to protect people around the world from potential health harms.
Some scientists note that it is difficult to separate the impact of UPF on people's diets from other factors in people's lives, such as lifestyle, behavior and wealth.
Critics of Nova's classification system say it relies too much on the level of processing of the food rather than on how nutritious that particular food is. For example, whole grain breads, breakfast cereals, low-fat yogurts, infant formula, and fish fingers are all considered ultra-processed but contain many health benefits.
Professor Kevin McConway, Emeritus Professor of Applied Statistics at the Open University, said: “A study like this may find a correlation, but it cannot be sure of cause and effect.”
He said there was “still room for doubt and clarification from further research.”
“It seems likely to me that at least some UPFs may cause an increased risk of some chronic diseases. But this, of course, does not mean that all UPFs increase the risk of disease.”
It is still unclear what ultra-processed foods may cause or contribute to disease.
Professor Jules Griffin, from the University of Aberdeen, said there were some positive aspects to food processing and “more research is urgently needed to understand how it affects our health.”
The Food and Drink Federation (FDF), which represents the industry, says UPF can form part of a balanced diet, such as frozen peas and wholemeal bread.
“Over the years, companies have made a number of changes to make the food and drink we all buy healthier, in line with government recommendations,” says Kate Halliwell, chief scientist at FDF.
The amount of sugar and salt in foods sold in shops and supermarkets has fallen by a third since 2015, she added.
UK Nutrition Scientific Advisory Committee Earlier this year said the link between higher consumption of ultra-processed foods and adverse health effects was “alarming”.
But it added that it is “unclear” whether these foods are unhealthy because of processing or because many are high in calories, saturated fat, salt and free sugars.
Current UK government dietary advice is to eat more fruit, vegetables and fibre, and reduce your intake of sugar, fat and salt.
