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Series 5: Is the Ultra-processed Food (UPF) concept useful, and for what goals?

It is hard to open a newspaper or lifestyle magazine now without finding the concept of ‘ultra-processed food’ somewhere mentioned. Based on the idea that not only a product’s content but the processes involved in its manufacture determine its health value, UPF has captured public attention. How useful is the classification, and what can its use achieve? In this TABLE Letterbox Exchange, Rob Percival, Anthony Warner and Mike Rayner were asked to consider in their debate i) the multiple understandings of the UPF concept, ii) the context and conditions of its successful or unsuccessful use, and iii) the relative goals and outcomes of i) and ii). The Letterbox will feature a total of nine letters. Read more about the origins and terms of the concept in TABLE’s UPF Explainer

Headshot of Rob Percival, Head of Food Policy at Soil Association

Rob Percival

Rob works for the Soil Association, an organisation advocating for healthy and sustainable food and farming. As Head of Food Policy, he leads their advocacy and influencing around dietary change and food system transformation. He is also the author of 'The Meat Paradox', a book about the cognitive and cultural complexity of meat. @Rob_Percival_


The Soil Association is the UK's leading food and farming charity advocating for healthy and humane food, farming and land-use. @SoilAssociation


Headshot of Anthony Warner, development chef and author

Anthony Warner

A development chef and food writer working on projects to improve the health and sustainability of commonly eaten foods. Writes about food systems for newspapers, magazines and the Angry Chef Blog. Author of an award winning trilogy of books on food system health and sustainability. Founder of the Fruition Food Accelerator, supporting innovative food start-ups in the North of England. @One_Angry_Chef


New Food Innovation is a consultancy working at the intersection between academia and industry, helping to bridge the gap between Universities and Corporates. They specialise in nutrition, health and plant-based foods and include an investment support arm.


Headshot of Professor Mike Rayner, Nuffield Department of Population Health

Mike Rayner

Mike Rayner is a Professor of Population Health at the Nuffield Department of Population Health. Formerly he was Director of the Centre on Population Approaches for Non-Communicable Disease Prevention, based in the department, which was a World Health Organisation Collaborating Centre from 2013- 2021. 

Mike's research has been on all aspects of the prevention of non-communicable diseases with a focus on population based interventions to promote healthier eating such as improved food labelling, restrictions on the marketing of foods and health-related food taxes such as taxes on sugary drinks. He has a particular interest in nutrient profiling. 

Mike is also Chair of Sustain: the alliance for better food and farming in the UK, and Chair of the Nutrition Expert Group for the European Heart Network. He is an ordained priest in the Church of England. @MikeRayner

Headshot of Rob Percival, Head of Food Policy at Soil Association

Dear Anthony and Mike, 

You’ll be aware that ultra-processed foods (UPF) have been in the spotlight of late, prompting a lively and often heated debate. It’s my contention that the UPF concept and associated NOVA system, applied appropriately, advance our understanding of dietary health and food system politics. I believe governments should respond accordingly. This letter is written in anticipation that our views may differ, in the spirit of furthering the debate.

As an opener, allow me to outline the contexts in which the UPF concept is commonly applied (or misapplied). To my mind there are (at least) four. UPF may be understood as (i) a designation describing the degree and purpose of processing applied to a food product; (ii) a frame within which to assess the health outcomes associated with dietary patterns; (iii) a conceptual lens for viewing the political economy of the food system; and (iv) part of a body of evidence that might inform policy. Let’s take these one at a time.

As a designation applied to food products, you’ll know that ‘ultra-processed’ derives from the NOVA system devised in 2009 and honed over subsequent years to describe four categories: N1, minimally processed foods; N2, processed culinary ingredients; N3, processed foods; and N4, ultra-processed foods.

It’s worth stressing that this is all NOVA does. In popular discourse, ‘ultra-processed’ is sometimes taken to imply a value judgement (‘UPF = bad!’) or as a blanket condemnation of diverse products as uniformly ‘unhealthy’. There are lots of reasons ‘UPF’ carries such connotations, but they are not intrinsic to NOVA. There is no value judgement in NOVA; the system doesn’t tell you whether a food is good, healthy, ethical, or sustainable. All NOVA does is categorise food products according to the degree and purpose of processing.

What’s the value in that? Well, researchers have harnessed NOVA to assess the health outcomes associated with different dietary patterns. Diets rich in UPF have been associated with poorer health outcomes, and for reasons which appear to extend beyond nutrient composition.

As with nutritional epidemiology more broadly, scientists have had to grapple to accurately measure intake and isolate confounding factors, and no doubt NOVA-based research will continue to grow in sophistication in years to come, but the evidence is already compelling. Dozens of cohort studies controlling for salt, fat, sugar, and overall diet quality, have found UPF-rich dietary patterns robustly and independently associated with poorer health outcomes. A randomised controlled trial similarly found a UPF-rich diet caused an increase in ad libitum calorie intake and weight gain. Hypothesised mechanisms underlying this association relate to properties that blunt satiety signalling, organoleptic characteristics associated with higher energy intake rate, and additives that might act as endocrine disruptors or disturb the microbiome. It’s likely that multiple mechanisms are simultaneously at play across the span of an ultra-processed diet. 

UPF are defined by the ‘purpose’ as well as ‘degree’ of processing. That purpose, broadly speaking, is product design for profit maximisation. UPF are often designed to either displace NOVA 1-3 foods or generate novel eating opportunities (snacking etc) and engineered for repeat purchase. UPF might also be designed to be convenient, safe, or rich in chosen nutrients, but there are few incentives in the system to motivate manufacturers to prioritise public health over corporate profit. The UPF concept thereby contributes to our understanding of the commercial determinants of dietary health.

In the context of a globalised food system, the UPF business model has been very successful. UPF is displacing traditional cuisines and indigenous food cultures worldwide, part of a dietary transition shaped by social, biological, and economic drivers. Underpinning this transition is a food production paradigm predicated on trade liberalisation, agrochemical intensification, and mass production of cheap commodity crops. The externalities for climate, nature, and health are well documented.

These are broad brush statements (as demanded by the format) and as such open to dispute. Allow me to plough even deeper into disputed territory by commenting on potential policy implications. How should governments respond?

We probably agree that governments should invest in research concerning UPF. The case can be made, however, that this research should not impede more immediate action, the evidence having now reached a ‘critical mass’. I would argue that there are ‘no regrets’ policies that should be implemented now, and that we are obliged to take a precautionary approach, especially in relation to child health. This line of reasoning would lead to NOVA being employed alongside nutrient profiling to inform policies aimed at re-balancing diets across the social gradient towards minimally processed foods and healthier processed foods, away from UPF.

If such proposals are controversial, it is partly because they threaten the industry’s business model. If ultra-processing is the issue, and not only salt, fat, or sugar, and if reformulation has limited potential as a public health strategy, then how is industry to respond? Both legitimate and illegitimate lines of critique have been levelled against NOVA, the latter sometimes deriving from this thorny challenge posed to industry. Paradigm shifts are uncomfortable, especially for those in eclipse. 

For these reasons, in these contexts, I find the UPF concept to be of utility and value. Would you agree? I look forward to your response. 

Yours sincerely,


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Headshot of Anthony Warner, development chef and author

Dear Rob and Mike,

We certainly agree that the concept of Ultra Processed Food has been in the spotlight recently, largely due to a few fierce, media savvy advocates.

Given the recent academic and media discourse, any assertion that UPF doesn’t constitute a value judgement does not hold water. Foods falling under the NOVA 4 category are frequently presented as being of low value by advocates, if not outright demonised. Surely the very concept of classifying foods by the ‘purpose’ of processing - clearly a matter of opinion - implies value judgement.

We should base our nutrition choices, especially when it comes to policy, on the totality of available evidence. The claim that ‘the evidence is already compelling’ presumably refers to the media traction UPF has gained. It surely cannot refer to the actual totality of evidence, which has been systematically reviewed by experts and found wanting. Only this year, the UK’s Scientific Advisory Committee on Nutrition (SACN) recommended against UPF-based policies, concluding that there were ‘uncertainties about the quality of evidence’ and observed associations were ‘already covered by existing UK dietary recommendations.’ Similar boring, grey committees of independent experts in the Nordics and the US have found the evidence equally weak. Some of the most qualified people in the world have spent months reviewing hundreds of papers and found little of interest.

It is very easy to cherry pick a few bits of nutrition research to make a rhetorical point. But for guidance on matters of nutrition we should look to the sort of committees that spend months poring over hundreds of references and conducting independent systematic reviews. ‘Dozens of cohort studies’ may have come to negative conclusions on UPFs, but there are many others suggesting something different. To make informed decisions, we have to consider all the evidence together. Several UPFs are found to be associated with positive health outcomes, particularly those containing fibre and added micronutrients. To ignore this counter evidence is to depart from the pursuit of truth, perhaps the difference between advocacy and science.

Almost all research into ultra-processed food is from observational studies, which in nutrition science are notoriously unreliable. Papers that propose mechanisms such as endocrine disruptors or disturbances to the microbiome are usually poorly evidenced, often only supported by a single reference. Such a basis is sufficient for purveyors of fad diets, but not for serious decisions about health. In contrast, committees that assess the safety of food additives in the UK and Europe review hundreds of pieces of research for each assessment, often demanding additional studies before approval. They are notoriously risk averse; exactly the sort of ditch-dull independent committees we should look to. Why should we suddenly believe they are wrong?

To claim that evidence has reached a ‘critical mass’ is frankly absurd. The only ‘critical mass’ is the weight of agenda-driven media frenzy. No one with an interest in truth should ignore the findings of organisations like SACN, the USDA and NNR, particularly not in favour of media personalities with books or health tracking apps to sell, who have dominated much of the media discourse on this topic.

There are not ‘no regrets’ policies here. Anything that demonises perfectly sensible food choices comes with regrets. Anything that makes staple foods like sliced bread more expensive or less available comes with regrets. Not everyone has well-equipped, middle-class kitchens and family dining tables. Not everyone has the time or capability to cook organic fresh foods. For many vulnerable groups, processed foods represent easy, affordable nutrition that they cannot get elsewhere. For the elderly, disabled and sick, processed foods can be a lifeline. Making such things more expensive, harder to access and painting them with guilty associations will cause genuine harm. To do so when the totality of evidence says not to, would be criminal.

If we do have some common ground, it is probably an agreement that food has an important role to play in health. The main reason I do not support NOVA is that placing most of the food people currently eat into a single, arbitrary category and then regulating against it is not how we improve diets. Damning all UPFs would remove incentives to improve the food that people actually eat. Valuable activities by both companies and academic institutions to reduce the level of processing, increase the quality of fibre, lower saturated fat, fortify with micronutrients, or reduce calorie density would be rendered pointless in such a system. However much the nutritional quality of a manufactured food is improved, under this system it would still be considered a UPF, and so still demonised as an unhealthy choice. 

Assessing the healthfulness of foods by the categories into which a Brazilian nutritionist, motivated by the anti-capitalist impulse of reducing the influence of large corporations, places them into is foolish and anti-science. I strongly believe that basing UK health policy on such a system would cause immediate harm to vulnerable people and make it harder to improve the food system in the long term. I am thankful that measured, sensible assessments by independent committees still have value in this country, but I do fear that the rise of soundbite politics may eventually mean concepts like UPF enter into policy by the back door.

Kind regards,


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Headshot of Professor Mike Rayner, Nuffield Department of Population Health

Dear Anthony and Rob,

Yes I think we can all agree that food has an important role to play in health. We probably also agree that diets in the UK are unhealthy and unsustainable and that something needs to be done about that. And yes the concept of Ultra-Processed Food (UPF) has been in the spotlight recently. The main question for me here is what is the value of the concept of ultra-processed as opposed to other derogatory descriptors for foods such as ‘unhealthy’ (as defined by nutrient profile models) or indeed just ‘junk’? Rob clearly thinks there is considerable value and Anthony does not. But first we need to agree on what we mean by the term UPF.

I think Rob is right to suggest that the concept has multiple meanings including an objective ‘designation describing the degree and purpose of processing applied to a food product’ and a subjective ‘conceptual lens for viewing the political economy of the food system’. These are quite different meanings! Without agreeing what we mean by UPF we risk talking at cross-purposes in these exchanges as in many other such discussions.

For me Rob’s first meaning of UPF – as a designation for a manufactured food that is highly processed - is more useful than his second – a conceptual lens for viewing the food system. The NOVA system provides the most commonly used definition of UPF but this definition is based not just on the degree of food processing but also its purpose. For me this is a huge barrier to its usefulness – not only for academic research but also in food policy making. As Anthony points out, adding ‘purpose’ to ‘degree’ in the NOVA definition of UPF introduces considerable subjectivity. How can you tell, say from the food label, the purpose of the processing involved? How then would you be able to regulate the marketing of UPF if you so desired?

Even if subjectivity can be reduced for scoring the degree and purpose of food processing the NOVA system has other drawbacks. It draws a line between UPF and other classes of processed foods which seems arbitrary and has the effect of allowing no distinction to be made between highly processed UPFs (such as sugar sweetened beverages) and not so highly processed UPFs (such as most breads).

On the other hand the evidence for an inverse relationship between the degree to which a food is processed and its healthiness is growing, even if more research is needed to clarify the reasons for why that is so. I am tempted to agree with Rob that such evidence has reached a ‘critical mass’ to which ‘governments should respond accordingly’ (as indeed some are). But I worry (like Anthony) that an over-emphasis on the relationship between food processing and health might obscure the benefits of food processing – particularly when it comes to the environmental impacts of diets. 

I think the jury is out on whether the NOVA definition of an UPF will turn out to be the most useful definition of a highly processed food, or whether something more objective can be devised. The definition needs to be more objective if the concept is to be useful beyond its original context of dietary guidelines for Brazilians and in particular if it is to be used for food regulations.

Is the concept of UPF a useful conceptual lens for viewing the political economy of the food system (Rob’s second meaning of UPF)? Rob seems to think it is: linking the growth of UPF production and consumption with trade liberalisation, agrochemical intensification, and mass production of cheap commodity crops. Anthony thinks this lens is ‘motivated by the anti-capitalist impulse of reducing the influence of large corporations’ and surely Rob would agree with that. As an anti-capitalist myself I think this is all too simplistic and risks distorting the diagnosis of the problems and identification of the solutions to unhealthy and unsustainable diets.

For me the UPF concept puts too much emphasis on the manufacturing link in the food chain. We have come to realise that to attain more healthy and sustainable diets we need to switch from animal based foods to plant based foods (whether they are processed or not). It is not just the processing of foods which makes them unhealthy and unsustainable but the raw materials as well. The emphasis on food-processing as the main problem with the food system, or even just as symbolic of those problems, surely distorts the discussion of what we need to do to improve the healthiness and sustainability of diets.

Best wishes, 


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Headshot of Rob Percival, Head of Food Policy at Soil Association

Dear Anthony and Mike,

I’d like to unpack one line of criticism that recurs across your responses. You both seem to agree that the purported ‘subjectivity’ of NOVA is problematic. Mike writes: “Adding ‘purpose’ to ‘degree’ in the NOVA definition of UPF introduces considerable subjectivity… the definition needs to be more objective if the concept is to be useful.” Anthony similarly warns that NOVA’s political dimension is “foolish and anti-science”.

Implicit in these comments appears to be the view that, beyond NOVA, there are areas of nutrition science which are objective and apolitical. NOVA is undesirable in that it sullies these clear waters.

In response, I’d like to return to the origins of NOVA and to Carlos Monteiro as its architect. I enjoyed Anthony’s description of Carlos as “a Brazilian nutritionist, motivated by the anti-capitalist impulse of reducing the influence of large corporations.” This conjured (to my mind, at least) the image of a Che Guevara figure – Monteiro in a leather motorcycle jacket, biking around Latin America, preaching the Brazilian dietary guidelines as his neo-Marxist creed. But that’s not quite how this began. Monteiro was indeed concerned that multinational corporations were trampling over indigenous food cultures, but he was also grappling with a more mundane paradox. People in Brazil were eating less sugar and fat, yet they were becoming heavier and unhealthier. This ran counter to the prevailing wisdom.

You’ll be aware that for the past half century dominant strands of nutrition science have focussed narrowly on single nutrients as determinants of health, an outlook characterised as ‘nutritionism’. Within this reductive paradigm, nutrients are systematically decontextualised from the foods, dietary patterns, social contexts, and food systems in which they are embedded. The problem to be solved is fat, or fibre, or sugar. Monteiro understood that this perspective could not explain the trends he was observing in Brazil. NOVA was conceived to illuminate the bigger picture.

It’s important to recognise that ‘nutritionism’ did not become the prevalent paradigm by accident. A narrow focus on ‘nutrients of concern or benefit’ neatly coheres with an ultra-processed business model, for it allows UPF companies to fortify, functionalise, or reformulate their products, and to market them with a health claim. UPF companies have accordingly engaged in a range of ‘corporate scientific activities’ aimed at creating and perpetuating a body of knowledge characterised by reductive nutritionism. These activities include the funding and framing of nutrition research; sponsoring scientific seminars and events; involvement in scientific standards and policy committees; and funding scientific front groups to influence policy, regulation, and media narratives.

These front groups are active in the UK, where the UPF industry is deeply embedded at the interface of science and policy. Financial ties to ultra-processed food companies can be observed in high-level UK Government committees, including the Scientific Advisory Committee on Nutrition (SACN) which recently formed a view on UPF. Anthony claims that in reaching this view, SACN reviewed “the actual totality of evidence”. They did no such thing. The committee critically analysed twelve studies related to UK consumption – a worthwhile exercise, but far from the “actual totality” of the available evidence, especially if one looks beyond nutritional epidemiology to relevant evidence pertaining to commercial determinants and food system politics. SACN’s review was nutritionism in action.

I willingly concede that NOVA’s conjoining of ‘purpose’ with ‘degree’ can feel disorienting, but this is primarily because we’re not (at least in our culture) accustomed to thinking in such a hybrid manner. NOVA makes salient a political domain that is often obscured from view. If UPF discourse was to vanish overnight, we would not be left with a research and policy agenda purged of ‘subjectivity’. No area of science is apolitical or wholly objective – the accumulation and implementation of scientific knowledge does not take place in a social or psychological vacuum. It’s a human endeavour.

That is not to say that NOVA cannot be employed in an ostensibly ‘objective’ (even reductive) manner. One can readily use NOVA to categorise foods according to a defined set of physical transformations or characteristics. Many scientists are employing the system in this way, investigating the molecular and physio-chemical components of UPF and their relation to bodily health. But the inclusion of ‘purpose’ within NOVA’s definition provides an in-built ‘telescoping’ mechanism that persistently draws attention back to the big picture, micro to macro – from the molecular level to whole foods, dietary patterns, commercial determinants, and food system drivers.

And herein lies the system’s value. NOVA punctures the pretence of the apolitical. Implicit in NOVA is the understanding that dietary health can only be understood in this larger context, which encompasses corporate profit motives. It compels us to recognise that another decade of UK dietary health policy myopically focussed on reformulation and ‘nutrients of concern’ is a decade wasted. We either pursue more structural transformations to food systems and diets, or we will continue to fall sick. The ‘purpose’ component does not muddy the waters but deepens them. What you perceive to be the system’s weakness may be its greatest strength.

All best wishes,


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Headshot of Professor Mike Rayner, Nuffield Department of Population Health

Dear Rob and Anthony,

I’d be happy to unpack my criticism of the subjectivity of the NOVA system for classifying foods. Yes I do think this subjectivity is problematic and particularly when it comes to using the system for certain policy-related purposes such as more understandable food labelling, restrictions on the marketing of foods, food taxes, etc., all of which I think will be important if we are to ‘pursue more structural reforms to foods systems and diets’ as Rob put it. The subjectivity of the system doesn’t matter so much when providing dietary advice, or even research into the impact of food processing on health and environmental sustainability where it can be taken into account.

You say, Rob, that implicit in our comments appears to be the view that, beyond NOVA, there are areas of nutrition science which are objective and apolitical. I cannot speak for Anthony but of course I am not saying that. I agree that multinational food companies are ‘deeply embedded at the interface of science and policy’ and nutrition science is particularly prone to the influence of vested interests and not just commercial interests.  I believe all science is political and some of my scientific heroes of the first half of the 20th century – like Joseph Needham, JD Bernal and Lancelot Hogben - were members of the Communist party or sympathisers. These giants believed that objectivity is important if science is to be useful for society and I do too.

The objectivity of a system for classifying foods is important when there is a need for transparency and replicability e.g. when designing regulations to restrict the marketing of highly processed foods. Regulators need to have a way of determining whether an individual food can be marketed or not based on criteria that are clear to the producers, i.e. objective. The NOVA system seems to me to be wanting in this respect and therefore is less useful than it might be.

My first problem with the subjectivity of NOVA is with its design. It doesn’t make sense to me to say that a cake made at home for the purpose of eating at home should be classified as ‘processed’ and therefore not too unhealthy. But the same cake, with exactly the same ingredients, made in a factory for the purpose of selling it to a consumer, should be classified as ‘ultra-processed’ and therefore ultra-unhealthy. Of course a cake made in a factory is likely to have more additives than the cake made at home but the presence or absence of additives by itself doesn’t determine which NOVA class a cake falls into.    

But my main problem with the subjectivity of NOVA is in its application. You say, Rob, ‘One can readily use NOVA to categorise foods according to a defined set of physical transformations or characteristics,’ i.e. by ignoring the purpose of the food processing involved in the production of the foods.  

Even if we ignore ‘purpose’ I am not at all sure about ‘readily’. If you ask two or more people to classify a list of foods using the definitions for NOVA classes then you end up with a lot of inter-rater disagreement. How much disagreement depends on the amount of information the raters have about the foods, the type of food, the raters’ understanding of phrases such as ‘relatively simple industrially manufactured food’ (part of the definition of ‘processed food’). The raters also need to be familiar with the lists of foods that NOVA provides as examples of its four classes. Yoghurt, for example, appears in two different classes depending on whether they are ‘plain’ or ‘flavoured’. And then they need to know whether, for example, flavoured with sugar counts as ‘flavoured’.

It is true that all classification systems used for foods (including those used in food regulations such as ‘subject to Value Added Tax’ or ‘organic’) are, to a greater or less degree, subjective, but they nevertheless seek to be as objective as possible in their design and to reduce the subjectivity required for those applying them.

I do think that an objective definition of a highly processed food (HPF rather than UPF) would be a useful tool for nutrition scientists studying the health and environmental impacts of foods. And there have been various attempts recently to improve definitions of level of processing e.g. by defining precisely which food additives make a food more highly processed, or which nutrients are more or less likely to appear in highly processed foods. I also think that other systems for classifying foods for food policy purposes (such as nutrient profile models) need to take more account of food processing. And, in part, related to the development of the NOVA system, this is happening.

I agree with you, Rob, that ‘We either pursue more structural transformations to food systems and diets, or we will continue to fall sick’ and I presume we agree that we need better tools to implement those transformations. I do not agree with you, Rob, that the ‘purpose’ component of the NOVA system is its greatest strength in this regard. I do think its subjectivity is its greatest weakness.

Best wishes,


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Headshot of Anthony Warner, development chef and author

Dear Mike and Rob,

Personally, I really like objective science. In nutrition, it has achieved a great deal. It has transformed our food system from one where for most of history 90% of the population regularly experienced severe hunger, to one where only 10% do. Since the discovery of vitamins in the early twentieth century, deficiency diseases in the UK, Europe and the US, once affecting the majority of children, are now extremely rare. Our modern food system has its problems, but it is perhaps humanity’s greatest achievement, preventing more death and suffering than any other scientific advance. 

This transformation has almost entirely been driven by reductionist advances in agricultural, food and nutrition science. In more recent times, initiatives to reduce salt, fortify staple foods, cut saturated fat, remove trans fats, and lower the consumption of processed meats have saved thousands more lives. Some might see this extraordinary progress and think ‘there’s a paradigm that needs overturning’, but I personally believe that if we want to improve the food people eat, a continued pursuit of reductionist science is the most effective way forward. 

As for the nutritionism that Rob mentions, I find it to be a straw man argument. Nobody sensible working in nutrition decontextualises nutrients from the matrix in which they are consumed. Bioavailability, starch digestibility, glucose response and countless other factors are all well known to be dependent on the context in which foods are eaten. Although this context is often complex, much of nutrition science involves studying it objectively.

Every dietitian and nutrition scientist working today also understands that overall dietary patterns and societal factors are highly significant in determining health. Although reducing sugar, salt and saturated fat are important public health messages, there is not a single set of dietary guidelines that only focuses on single nutrients. There are globally consistent messages to eat more whole plant-based foods and reduce the consumption of animal derived products. Nutritionism seems to be a convenient (and ironically reductionist) myth, created to bash nutrition scientists when they speak inconvenient truths that don’t align with cultural prejudices about food.

As someone who is interested in making food systems healthier, I am always open to exploring new ways of doing this. As such, the integration of the NOVA system into the Brazilian Dietary Guidelines since 2014 provides a fantastic case study. Curiously however, information regarding the success of this change in transforming the dietary health of Brazil is lacking, and prevailing trends of obesity and poor dietary health seem to have continued regardless. Perhaps the fundamental issue with all dietary guidelines, and the reason why real change is so hard, is that nobody follows them. People eat the foods they enjoy, so to improve diets, we probably need to stop moralising about their choices, and focus on making healthier foods more delicious and affordable. 

It is fine to dislike capitalism. There is much about it to dislike. It is almost certainly correct that a small number of global companies control far too much of the food system. But it is worth noting that within certain parts of the capitalist food system, the NOVA classification system has been warmly welcomed. For the $1 trillion global meat and livestock industry, the idea that processing is the main problem when it comes to health is quite an absolution, considering the known health and environmental harms of high meat consumption. Under NOVA, we can all eat plenty of unprocessed steak cooked in butter, so long as we avoid wholemeal bread. It is no coincidence that meat lobby groups paid for a Superbowl advert this year, demonising plant-based burgers as Ultra Processed. The meat heavy 2014 Brazilian dietary guidelines must have made sweet reading for certain industry groups.

As a development chef working to make the foods that people commonly eat healthier and more sustainable, the NOVA system makes a mockery of these attempts. If NOVA is integrated into policy, it would render all such work pointless. Any attempts to improve the nutritional quality of manufactured foods would be replaced by pointless initiatives to move them into a different NOVA category. Low processed meat products, despite their known health and environmental harms, would gain a further advantage over plant-based alternatives.

I do not think that any of us believe the food system should not be regulated and controlled in some way. This does require us to classify foods, but in my opinion that classification system has to be based on objective science. No system is perfect, and science does evolve as our understanding grows, but NOVA departs so far from objectivity as to be useless in any practical sense. It allows a loophole through which the $1 trillion global meat industry can absolve its produce from blame. It defines bacon cooked in lard as a healthier breakfast choice than muesli and yogurt. It demonises baby formula and scuppers any attempts to improve the nutritional quality of commonly eaten foods. And perhaps worst of all, it makes millions of people feel guilty about the perfectly sensible food choices they make for their family. 

For that, more than anything, I find the moralising of NOVA’s advocates unforgivable. To hear families say they are ashamed of making fish fingers or beans on toast for their tea, and being falsely led to believe that such foods are causing their children terrible harm, is not a fair price for some ill-defined political goals. 

Kind regards,


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Headshot of Rob Percival, Head of Food Policy at Soil Association

Dear Anthony and Mike,

You’ve raised concerns regarding meat consumption, suggesting NOVA might be misaligned with efforts to shift diets (as is needed in affluent populations) from animal foods towards plants. Of particular concern is the appropriation by the meat industry of the term ‘ultra-processed’, which has been selectively employed by lobbyists to dissuade people from consuming plant-based products, thereby entrenching meat-rich dietary patterns. I share your concern in this regard. 

But, as ever, it’s important to differentiate science from industry spin. NOVA does not give a green light to uninhibited meat consumption. On the contrary, NOVA-based research strongly associates UPF-rich diets – and those are diets rich in burgers, sausages, nuggets, and other reconstituted meat products, also often lacking in pulses and vegetables – with poorer health outcomes. In the UK, UPF represents the largest category of meat consumed. NOVA-based science implies we should be eating much less, and NOVA-informed dietary guidelines, such as those in Brazil, accordingly advise people to consume foods “mainly of plant origin” and to eat animal foods “in small quantities” only.

On a food system level, ultra-processing and industrial animal farming are symbiotic. Both are driven by the intensive production of cheap commodity ingredients and the incentive to add profit along consolidated supply chains, typically either by manufacturing commodity crops into saleable ultra-processed products or by forcing those crops through a factory farmed animal (whose flesh is often subsequently processed into UPF). Indeed, the defining feature of the global ‘nutrition transition’ is the displacement of diverse indigenous food cultures by a ‘Western’ monocultural diet rich in both UPF and factory farmed meat. They are two sides of the same coin.

Of course, this is not how the meat lobby has presented NOVA, especially in the U.S., where the term ‘ultra-processed’ has been weaponised to attack plant-based products and mask the harms caused by industrial meat and dairy. This is dishonest. While one segment of the industry (selling snacks, drinks, and so on) is voraciously dismissing concerns about ultra-processing, saying, ‘NOVA is nonsense, keep buying our product!’, another segment (selling burgers, nuggets, and so on) is simultaneously appropriating the term, saying, ‘NOVA (our warped version of it) is gospel, keep buying our product!’ Neither tells us much about NOVA itself; both speak of the wilful contortion of science by corporate interests.

This contortion is pervasive in UPF discourse. Anthony suggests that, “Under NOVA, we can all eat plenty of unprocessed steak cooked in butter, so long as we avoid wholemeal bread”, and that NOVA “defines bacon cooked in lard as a healthier breakfast choice than muesli and yogurt”. NOVA says no such thing. These statements might bear resemblance to meat lobby rhetoric, or claims made on social media, but neither is substantiated by NOVA-based science. Neither reflects the nuance or balance of NOVA-informed dietary guidelines, which repeatedly caution (on both health and environmental grounds) that meat and animal foods should be eaten “sparingly”. Anthony is perhaps alluding to the recommendation that people “avoid ultra-processed foods”. Some yoghurts and breads fall into this category. But the guidelines stress that one should choose less highly processed versions of the same product or category, where available. The advice is to eat less highly processed bread and yoghurt, not to gorge on lard.

Why is misinformation about ultra-processing so rife? It’s partly because industry-linked actors have deliberately sought to sow confusion and doubt. The UPF industry bears resemblance in this regard to the fossil fuel, tobacco, gambling, mining, and pharmaceutical industries, where the same pattern of ‘corporate political activity’ has been observed. In each case, industry voices have sought to co-opt the fields of policy making, science production, and public opinion, making it difficult to disentangle propaganda from reality, rendering corporate-sponsored values and narratives dominant.

The purported difficulty (which Mike alluded to in an earlier letter) of applying NOVA in a consistent manner provides a salient example. Evidence for this difficulty primarily derives from industry-linked studies. In studies where the authors have no financial or non-financial competing interests to declare, and where NOVA is applied by trained individuals, there is less than 5% disagreement in product category assessments. 

It bears repeating that NOVA can readily be used to categorise foods according to a defined set of physical transformations or characteristics. Many scientists have employed the system in this way – across large, long-duration, carefully conducted cohort studies, and randomised control trials, both published and in development – to investigate the impacts of UPF-rich diets on bodily health. This research is advancing apace and is already informing policy in diverse contexts, a trend that is likely to grow exponentially once a ‘regulation friendly’ iteration of NOVA is published. Such an iteration, further enhancing the system’s specificity and granularity, is already in development.

NOVA offers an avenue beyond the reductive nutritionism that industry cleaves to, an opportunity to build on those health improvements obtained through the hard work of nutrition scientists and public health advocates. It is ‘fit for purpose’ in science and policy, and there is growing public appetite for a political response. 74% of UK citizens say they would welcome government action on UPF. This need not involve ‘demonising’ or ‘damning’ ultra-processed products; it has nothing to do with ‘banishing’ veggie burgers or ‘moralising’ everyday food choices. The challenge is simply to reconfigure food systems so that everyone can access and enjoy a healthy and sustainable diet. NOVA reinforces the understanding that such a diet should be based around diverse, minimally processed foods, mostly plants. Climate, nature, and human health all stand to benefit. It is only industry obfuscation that stands in our way. 

All best wishes,


Expand full letter

Headshot of Anthony Warner, development chef and author

Dear Rob and Mike,

I must admit, having read some of the letters in this exchange, I am now a little confused about what NOVA actually is. I thought it was simply a system of classifying foods by the level of processing they undergo. Apparently however, it has some curious dualities. It moves ‘beyond reductive nutritionism’, whilst at the same time being able to ‘categorise foods according to a defined set of physical transformations’. It is regularly co-opted by meat industry lobbyists, yet also the victim of coordinated cross-industry campaigns to discredit it. It defines foods by the ‘purpose’ of production, yet can still be applied reductively in terms of physical characteristics. It ‘punctures the pretext of the apolitical’ (quite an achievement for a food classification system), but still somehow ‘doesn’t tell you whether a food is good, healthy, ethical or sustainable’. 

Surely it cannot be all these things. If NOVA is about campaigning against the excessive influence of large corporations on our food system, that is fine. In many ways, that’s a cause I would support. But if it is a purely political classification system, it cannot also claim to be an objective measure of the healthfulness or sustainability. If, as Rob has stated, NOVA tells us nothing about whether a food is healthy, then it should not be used to create public health legislation. Its advocates really need to pick a team. 

If we want to improve the food system, very few people would argue against the need to classify foods for healthfulness and sustainability. The need to do this is not the battleground here. The battleground is whether NOVA is fit for that purpose, and whether there are better alternatives. In my opinion, there are many such systems. NutriScore, HFSS, Codex, EFIC, UNC and EPIC classification systems all offer ways of defining how healthy foods are. None of these are perfect, because food and our relationship with it is complex. But all show clear associations with positive health outcomes, and all have a basis in decades of thoughtful health and nutrition research. It is true that any such system will have room for improvement and should look to evolve with our understanding. The impact of food structure, food texture, eating rates, types of dietary fibre, micronutrient density and bioavailability need integrating, as will new knowledge when it comes along. But even in their current flawed state, none of these systems lead to the huge misclassifications that exist within NOVA. 

There are countless problems within the NOVA categories, many of which verge on the comic. Sugar sweetened drinks and highly processed meats are lumped in NOVA 4 with wholegrain bread, tinned soup and hummus. Putting all those items together in epidemiological studies, as most of the NOVA research does, will always create misleading results, leading to suggestions that hummus is causing us terrible harm. Huge amounts of time and resource are currently being wasted on such research, leading to damaging newspaper reports of killer baked beans and toxic vegan burgers. To me, this makes as much sense as looking for associations between foods that begin with the same letter of the alphabet, then saying we shouldn’t eat salmon because of sausages, sugar and Snickers. And when people complain, telling them that dark industry forces are just trying to cause confusion. But it is not industry obfuscation that causes these issues to be raised. It is because the broad nature of the NOVA classification system creates issues that responsible commentators cannot ignore. 

If NOVA does somehow become more granular in the way it categorises foods, then it will be a completely different system. Maybe then it will be more useful, but to enter into policy, there will still need to be objectivity. There will need to be potential mechanisms driving associations, and these will need to be proven in well conducted experimental studies. The problem is that unlike mining data sets for associations, that sort of objective nutrition research is difficult, expensive and time consuming. But taxing, rationing, or restricting foods, presumably the eventual aim of NOVA advocates, is hugely impactful and should never be done lightly. Just because NOVA has gained political and popular momentum, does not mean it should bypass normal process. If there is an objective scientific truth, prove it. But if NOVA is simply a political movement, keep it well away from nutrition research.

One of the reasons why food classification systems are such a source of division is that they often create results that stray from our pretensions and preconceptions around food. We instinctively believe that an artisan blue cheese is healthier than cheap processed burger slice, but a NutriScore rating might not agree. We think that a fine dining restaurant’s offering is inherently better for us than a Big Mac, but measurement of key nutrients might tell a different tale. NOVA, by design, is better at agreeing with our preconceptions, and I believe this is why it has so rapidly gained popularity, especially among wealthy Western food activists. It allows cultural predilections towards certain culinary choices, particularly more expensive and artisan ones, to be given a veil of scientific credibility. But we should not confuse a system that is easy to agree with, with one that is true. That is why the scientific method was created in the first place. We progress by following it, even when it feels wrong to do so.



Expand full letter

Headshot of Professor Mike Rayner, Nuffield Department of Population Health

Dear Anthony and Rob,

We seem to have covered a lot of ground in this Letterbox Exchange but we don’t appear to have reached much consensus. In our discussions we now seem to be treading over old ground but there are still a lot of issues where we have just scratched the surface. 

Perhaps one thing we can agree upon is that there is some confusion about what the NOVA system actually is. It is surely more than just a food classification system, Anthony? But can it be all the things you say it is, Rob? We can also probably agree that the term ultra-processed has grabbed the attention of the public in ways in which other terms used to describe foods have not. There is surely something to be learnt here.

Where we still don’t seem to agree is over the utility of the concept. Rob thinks it is useful, Anthony does not and I have my doubts. I do think that its emergence as a concept has had some benefits: for example, it has raised awareness about the downsides of some aspects of food processing e.g. when making unhealthy foods more attractive to consumers than they would be otherwise. But for me the concept also has its downsides, in particular its failure to take appropriate account of environmental sustainability.

In response to Anthony’s and my criticism that NOVA is misaligned with efforts to shift diets in developed countries from animal foods towards plants, Rob has raised the issue of the misuse of the concept – in particular by different sectors of the food industry - some using it for their own purposes to promote their non-UPFs (meat and dairy producers) and some vigorously opposing its use because they make their money from UPFs (most of the rest).  

Rob is right to distinguish the NOVA system itself and dietary guidelines of countries such as Brazil which recommend avoiding consumption of ultra-processed foods. Technically the NOVA system says nothing about the amounts of the foods in its four classes that are advisable and it is the guidelines which advise on amounts. But the NOVA system does surely imply that UPFs are less healthy than processed foods and I think Anthony is right to say, on that basis, that NOVA “defines bacon cooked in lard as a healthier breakfast choice than muesli and yogurt.”

NOVA also defines sugar-sweetened drinks, highly processed meats, wholegrain bread, tinned soup and hummus (if made out of the home) as all equally unhealthy – all UPFs – and that cannot be right. We surely need to agree that some UPFs are less unhealthy than others, as the recent study by Reynalda Cordova and her colleagues suggests. But as Anthony says, a more granular NOVA is not NOVA. 

Which brings me to what NOVA says about environmental sustainability. It was drawn up with mainly health in mind but some of its advocates have suggested that UPFs are less sustainable than other foods.   Can this be right? Studies of whether ultra-processed is or is not associated with indicators of environmental sustainability such as greenhouse gas emissions and land use seem to be distinctly lacking. It may be the case, as Rob says, that ‘ultra-processing and industrial animal farming are symbiotic. Both are driven by the intensive production of cheap commodity ingredients and the incentive to add profit along consolidated supply chains.’ But how does this play out when it comes to consumption: are ultra-processed foods thereby less environmentally sustainable than their non-ultra-processed alternatives? The answer is not obvious to me. Indeed on a-priori grounds the opposite might be the case: one purpose of food is preservation to avoid waste. Preservation means that less energy, and other resources such as water and land, are needed to produce one gram of food consumed. The energy needed to produce one gram of edible food mostly comes from fossil fuels which is one reason the food system contributes about a third of greenhouse gas emissions to global warming.   These fossil fuels are used in all stages in the food chain from production to consumption, but processing only accounts for 4-8% of food system emissions.

There is a growing number of studies to indicate which foods are more or less environmentally sustainable. And we now know which characteristics of foods are associated with greater or lesser environmental sustainability. These characteristics are mainly related to the species of the animals or plants that make up their ingredients.

We know that animal products are much less environmentally sustainable than plant-based products, that meat from cows and sheep is less environmentally sustainable than from pigs and chickens, that rice is less sustainable than wheat, etc. What happens to the animals or plants by way of processing, after slaughter or harvesting, seems to affect their sustainability very little: processed beef is just as unsustainable as unprocessed beef; sugar-sweetened drinks are just as unsustainable as sugar cane. Once again we surely need to agree that some UPFs are less environmentally sustainable than others but again, a more-granular NOVA is not NOVA.  

Rob is right to say that dietary guidelines such as those of the Brazilian Government that reference ultra-processed foods also tend to caution (on both health and sometimes environmental grounds) that meat and animal foods should be eaten “sparingly”. But the NOVA system, itself, does not distinguish between ultra-processed meat-based products and ultra-processed plant-based products, nor for that matter between fresh red meat and fresh vegetables. The lazy conflation of ‘ultra-processed’ with ‘unsustainable’ is, to me, worrying.  

The problems of climate change and environmental degradation are so important that demonising what is likely to be part of the solution - i.e. the development of ultra-processed plant-based products to replace meat – seems to me irresponsible. 

Best wishes,


Expand full letter


Summary: Each of our contributors has clear and distinct positions on whether the NOVA-based concept of Ultra-Processed Food (UPF) is a useful one, and in what conditions. Rob Percival proposes that the concept is valuable for four uses: i) a designation describing the degree and purpose of processing applied to a food product; ii) a frame within which to assess the health outcomes associated with dietary patterns; (iii) as a conceptual lens for analysing the political economy of the food system; and (iv) as part of a body of evidence that might inform policy. Anthony Warner counters that the subjectivity he identifies as inherent in the NOVA system distorts the classification beyond usefulness for either nutrition research or health policy. He allows its potential value for political analysis, but only in a context that maintains complete separation from nutrition research. Mike Rayner finds that while a tool classifying foods as highly processed is needed, the subjectivity he also finds in NOVA prevents UPF being that classification; while it may therefore play a role in dietary guidelines, it is unsuited for use in labelling and regulation. He sympathises with RP’s political aims, but feels that a classification system encompassing both health and the political must produce distortion in both uses.

Key arguments (+ in favour of / - critique of the concept):


 + A ‘critical mass’ of evidence has been reached connecting processing and health (RP, MR), including cohort studies and randomised trials.

 + Countries incl. Brazil, Chile and France have embraced NOVA in dietary guidelines and policy. 

 - In the UK (SACN), USA (USDA) and Nordics (NNR), scientific bodies have reviewed evidence to date and decided against adoption of the NOVA system at this time in regulation and policy (AW) [ - note the SACN review engaged with a sample of research papers rather than a ‘complete’ evidence pool (RP)].


 - UPF categorisation includes a ‘purpose of processing’ component - this cannot be objectively applied because it involves a value judgement (MR, AW).

 + Classification is achieved with less than 5% disagreement in studies (RP). 

Healthy choices

 - UPF categorisation does not distinguish between highly processed foods such as sugar-sweetened beverages and those that can form part of a healthy diet, e.g. packaged wholemeal bread, flavoured yoghurt, margarine, so is unsuitable for labelling.

 - Making decisions based on processing level can cause consumer confusion, e.g. suggesting that meat cooked in butter is healthier than muesli and plant milk (MR, AW).

 + Where NOVA is used in dietary guidelines it encourages swapping UPFs for less highly processed versions of the same thing, rather than to another product type, and promotes diets of which minimally processed foods make up the greater proportion (RP). 

Environmental analysis

 + The production model of UPFs is symbiotic with and conducive to mass production of cheap commodities, agrochemical intensification and monocultural agriculture (RP).

 - The most significant contributor to GHG emissions is raw material (i.e. type of plant or animal) rather than manufacturing - ‘UPF’ does not directly align with ‘unsustainable’ (MR). 

However, the letters only advance on sustainability in terms of emissions, not other environmental issues such as biodiversity loss, agricultural practice, soil health.

Open questions:

  • Is disparagement, even to the point of "demonisation", of certain food choices intrinsic to NOVA and the UPF classification? Or is that disparagement a case of misuse of the framework, something to which all nutrition classifications might be subject, and responsibility sits with advocates and media?
  • Subjectivity in classification is less of a barrier to political analysis: how can NOVA-informed political analysis support food system transformation or improvement? 
  • All agree the burden of responsibility for change away from highly processed diets should not fall on (vulnerable) consumers: does NOVA as a tool support or obstruct this aim? 
  • Industry and policy initiatives that draw on single nutritional classifications without reference to their role in wider health goals can be distorting or counter-productive: is NOVA more or less available to this than other classifications?
  • Does NOVA’s relevance change with geography and associated regulatory environments?

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