Food Technology Magazine | Issues and Insights
Photography by Alastair Philip Wiper
When researchers at the University of São Paulo, Brazil, first published their novel framework for grouping edible substances based on the nature, extent, and purpose of processing applied to food in 2009, they simply adapted the paper’s title, “A new classification of foods,” to name it. Using the original Portuguese for “new,” the system known as Nova classification was conceived as a fresh way to assess dietary patterns and their associations with health outcomes. However, the system has been criticized as oversimplifying a complex subject because it categorizes foods based on processing level alone, without considering other factors that affect nutritional value, like the quality of ingredients. Critics also argue that the Nova classification system can result in misclassifying or even villainizing healthy, nutrient-dense foods.
University of Copenhagen nutrition scientist and researcher Susanne Gjedsted Bügel thinks that it’s time to take Nova classification from new to newer. The professor, who is head of section for human nutrition, Department of Nutrition, Exercise and Sports at the University of Copenhagen in Denmark, is leading a new international consensus-building initiative that she thinks will do just that.
“We are excited to be leading a new international project that we hope will advance development of the next generation of the Nova classification,” Bügel explains. “Our aim is to build consensus in the global science community around taking the nutritional content and the potential effect of the food matrix of ultra-processed foods (UPFs) into consideration when using Nova. We believe it’s time to refine the Nova system, not only to address longstanding criticisms and concerns but to help improve the system by making it more precise to ensure a positive impact on public health worldwide.”
Food Technology spoke with Bügel about the nuts and bolts of the new project and the impact she thinks consensus will have on the global food system and consumers.
What do you think leads to misclassification in the Nova classification model, particularly with regard to foods included in certain categories that may affect public health recommendations or consumer perceptions of UPFs related to health and disease?
It’s the imprecision of the Nova classification system that I think is at the root of many scientists’ concerns. I think in the Nova system Group 4, ultra-processed foods, there are foods that have been broadly categorized and grouped together without distinguishing between what is good and what is bad in terms of human health. And I think we have to dive deeper into each and figure out what is actually healthy in this group and what is not healthy. Nutritional quality should be factored into the [Nova] classification.
One of my biggest concerns is that some of the foods that we consider to be healthy—and that have been claimed to be healthy by international public health authorities—are now claimed to be ultra-processed, a Nova classification defined as unhealthy. One of the best examples is rye bread, which here in Denmark is a basic staple food. It has a very high content of fiber and high consumption is one of the main reasons that the Danish people are getting a healthy intake of dietary fiber. If you buy it at the supermarket, rye bread is considered ultra-processed according to Nova classification, but if you go to your local bakery, it’s not defined as ultra-processed only because they are not putting additives or preservatives in the bread that increase shelf life. Rye bread is a healthy food that now is perceived as “unhealthy” merely because of a processing action or an additive that doesn’t affect its nutritional value.
Another example is some kinds of potato chips, which are products that are high in salt and fat but are not defined as UPFs because they contain only potatoes, oil, and salt, and that’s it. In other words, you can make food that is not categorized as ultra-processed but that is high in salt, sugar, and fat, and is actually unhealthy. So, this way of classification might misclassify unhealthy foods as not UPFs while other foods that have a high nutritional value are classified as ultra-processed just because they include one or two additives that are not detrimental to health.
Also, we have scientific evidence that not all additives are bad for you. An example of this is emulsifiers. Emulsifiers are a big group of compounds that, as a whole group, are claimed to be detrimental to health because they can interfere with the gut microbiota. However, one emulsifier, lecithin, for example, is a natural compound in many foods and is good for your gut health because it protects your mucus. So, some emulsifiers and other natural compounds can be beneficial.
How did the University of Copenhagen’s project on building international consensus around a next-generation Nova classification system come about?
It was really by coincidence. I have been interested in UPFs for some years as I have been conducting research into food and diet in relation to a transition towards a more plant-based or plant-rich diet. Our research team at University of Copenhagen has been involved in a research project, where we have looked at four different regions in Europe, including Copenhagen, and one in Africa to see at which stage of transition these areas were in terms of adopting plant-based diets in terms of sustainability and health.
Within that project, we also started looking into some of the plant-based alternatives to dairy (and indirectly, meat) and it began to appear that many of these alternatives are actually ultra-processed, or even consist of some substances that I wouldn’t even consider foods. And I think to drive the transition toward more plant-rich diets—and on purpose I’m saying plant-rich because I don’t think we should omit meat totally from our diets—it would require for many people that they have some easily accessible alternatives. As a result, I thought that we as scientists need to work together more closely with industry to figure out how we can do this in a way so that food is still healthy and not just a lot of chemicals put together. So, that started my interest in UPFs while at the same time, we began to see all these observational studies coming out showing that UPFs were bad for your health, but they didn’t distinguish between plant-rich or plant-based or meat-based.
Now for the coincidence. During a meeting with one of the directors at the Novo Nordisk Foundation [a Danish foundation that supports scientific, humanitarian, and social causes] on an entirely different matter, he introduced the topic of UPFs. He had some discussions with University of São Paulo professor Carlos Monteiro, [who led the development of the Nova classification and coined the term ultra-processed food], concerning the pros and cons of the system, and he thought this would be a good topic to explore. I was asked if I knew of someone who would be interested in helping initiate a new project looking into UPFs [and] the Nova classification system and updating it. Based on my experience teaching this topic on different courses, I said, ‘I think I would be the one.’
At first, they were looking to collaborate with a university to set up a network, but then they decided that they would like the university partner to be independent of the Novo Nordisk Foundation. We were invited to make an application and after a colleague and I designed the project and officially made the proposal, University of Copenhagen ultimately received the money for the proposed two-year project.
What activities are in the pipeline for the two years of the project?
The funding we received is to establish a network of experts from around the world who have expertise from different areas of science to discuss how we can refine the Nova classification, especially Group 4, through literature review, information sharing, and discussion to build consensus around the issues.
In January 2025, [we began] developing and convening a core group of experts for this project who will recommend the criteria we will use to select a broader group of experts to invite to the first of two workshops, which we plan to hold in Spring 2025 and Spring 2026. We want to be very transparent and communicative in this process because there are so many experts who would like to participate, and we believe it is important to include experts from a range of scientific and related disciplines from across the world. We intend to establish monthly online seminars, newsletters, and other communications as well, to keep people informed about the discussions and progress and to ensure that worldwide experts who are not invited to give opinions can also participate and share what they are doing in this area.
During the first workshop, we want to get ideas about what needs to be done to take the next step toward refining the Nova classification approach. We’ll want to look at the knowledge we have to date and identify the gaps in that knowledge in order to put nutritional quality into this system. Some of those gaps, such as the lack of intervention studies, might be identified through literature review or by experts. We’ll then produce a review to clarify those gaps and identify and invite additional experts who can help close those gaps to the second workshop in 2026.
By the end of the two-year period, we hope to be able to have evidence-based suggestions or recommendations for an updated classification system that we can publish in a report or consensus papers. We have already established a partnership with the British Medical Journal for these publications in some form, and a BMJ editor will facilitate the discussions at both workshops.
What role does collaboration among researchers play in the success of a potential updated Nova classification, and why is it important to include both supporters and critics of the original classification?
I think collaboration is extremely important because the topic is related to a lot of different [areas of] expertise. Processing and formulation are two different [areas] that are being mixed up in the Group 4 ultra-processed classification, so it will be important to have experts who specialize in those areas as well as nutrition, toxicology, additives, and more who can bring their expertise, collaborate, and weigh in on improving the precision and usefulness of the Nova classification system.
As for the pros and cons of the Nova classifications, it’s important to address [the concerns of] both the critics and those in favor [of the system] and get them together at the same table to come up with something that we can all agree on. If we want this [initiative] to be a success, maybe to a legislative level where we can [have an impact] or communicate effectively with the food industry that there are opportunities to do some things differently in processing and formulation that can have a positive impact on the nutritional value of the foods they produce, then we, as scientists, need to be able to discuss these concerns and come up with an agreement.
Will the group’s activities focus on any food-health mechanisms to clarify differing perspectives related to processing and nutritional value of UPFs?
The mechanisms explaining the association between consumption of UPFs and [a healthful diet] or chronic disease are still unclear and are not the focus of this project. However, mechanisms are important, and while I can’t say that our workshops, seminars, or literature reviews will focus solely on them, I am confident that they will be an important part of the discussion.
It’s a complex topic, of course. When we’re looking at all the associations that have been found in the observational studies, we see that mechanisms can be everything from Maillard products produced during food processing, such as advanced glycation end products that are formed when sugar and protein become glued together, which are associated with an increased risk of diabetes, to the consumption of extremely palatable food that causes weight gain or obesity, which then increases the risk of several chronic lifestyle diseases. Most of the evidence so far is from observational studies, which is not necessarily a causal effect. It could be that study participants are substituting real foods or healthy foods with a lot of [unhealthy ones] and that’s why they gained weight that led to chronic disease. In other words, it’s just a marker for a bad lifestyle, not a mechanism. Of course, it would be better to have intervention studies.
What excites you the most about the Nova classification update project and what impact do you think this work will have on the global food system and consumers?
Again, when I’m looking at all these observational studies that have been published, it looks very convincing that there are some products in Group 4 that are detrimental to health. But I can’t accept that all foods currently included in that group actually belong there, especially when we think about nutritional value. The fact is, we all need to eat, and we can’t stop people from wanting to have an easier life.
We also need to feed people in the world who do not have the resources, the capacity, or even the foods needed to live. Most of the food used as food aids to the developing world, including baby foods, are ultraprocessed, according to Nova classification. In developing countries, we need to improve how we formulate and process foods with sustainability and nutrition in mind.
So, I hope that by coming up with some suggestions from the scientific community on how to distinguish more precisely the food classifications outlined by the Nova system, that we can better work with the food industry to [modify] the processing techniques and the formulations or compounds that we are using for food production in such a way that we provide higher-value, safe and healthy food for the world community.ft