What’s the truth about UPFs? One year after the health warnings, a nutritionist evaluates

What are UPFs?

Numerous frameworks have sought to define ‘processed foods’ but the most widely used is the NOVA classification which was developed to provide a method of classifying foods according to the ‘level’, ‘nature’ and ‘purpose’ of processing. Although commonly applied, NOVA has been criticised for its broad definition which captures many energy-dense, nutritionally poor food products and classifies them alongside other manufactured foods.

The four classifications of NOVA are:

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Group 1. Unprocessed or minimally processed – these are natural foods which have been processed only in terms of cleaning or removing inedible parts (such as shelling or peeling), or perhaps freezing, drying or pasteurising. Examples include eggs, pasteurised or powdered milk, flour etc.

Group 2. Processed culinary ingredients – these are usually foods that are used as an ingredient to prepare, season or cook other foods. Examples include vegetable oils, butter and lard, sugar and molasses etc.

Group 3. Processed food – foods that have been altered by the addition of culinary ingredients or by methods like canning, curing and bottling. These may include tinned fruit and vegetables, cured or smoked meats and fish, freshly made unpackaged bread and cheese etc.

Group 4. Ultra-processed food – these are made from substances that have been extracted from foods or synthesised in a laboratory; they include carbonated drinks, flavoured yogurt, infant formula and follow-on milks, mass-produced and packaged bread etc.

Without doubt NOVA does appear to throw up some questionable groupings, for example powdered milk (group 1) is considered less processed than olive oil (group 2), and since NOVA’s inception in 2009, examples of foods in category 4 have varied – a current example being a packaged multi-seed sliced wholemeal loaf and a packaged white sliced loaf both being classed as UPFs. These anomalies arise because NOVA doesn’t take account of the nutrients in a food such as fibre, vitamins and minerals.

What was the early advice around UPFs?

With UPFs making up a significant part of our diets and the mounting evidence of an association to health issues, early advice suggested we should reconsider our eating habits and cut back on these convenient, often cost-saving, packaged foods.

Two trolleys, one containing healthy foods and the other with unhealthy foods

What do we currently know?

Processing changes the structure of food, known as the ‘food matrix’. This structure plays a role in determining how healthy a food is (along with other aspects such as added sugar and salt). However, it’s not a simple equation, as foods with differing degrees of structure can appear in all categories of NOVA. For example, the packaged multi-seed, wholemeal loaf bought from your local shop may be considered group four – but can still represent an important source of fibre and B vitamins and consequently carry less risk to health than a group three or even group two food.

Compelling and consistent they may be, but the numerous studies that have linked a high consumption of UPFs with health issues such as obesity, type 2 diabetes, heart disease, certain cancers and overall mortality rates, are largely based on observational studies. These studies involve researchers asking people about their diets and then assessing their health for a period of time. Although they provide valuable insights, such studies make it difficult to unpick the impact of less healthy diets or lifestyles and don’t provide us with the essential ‘cause and effect’ that we so clearly need.

So where does this leave us?

As the evidence stands, we don’t know the mechanisms behind these findings – is it the lack of nutrients or the high levels of fat, sugar and salt that are to blame? Perhaps it’s the change in the food’s structure or the way these foods influence our appetite? Or maybe it’s the use of additives such as emulsifiers, colours and flavourings? Or is it aspects of a consumer’s lifestyle such as whether they smoke, drink alcohol or lead a sedentary lifestyle?

Some studies have even suggested that the type of UPF may be relevant, with ready-meals containing meat, poultry and seafood showing higher associations with mortality risk. Sadly, we simply don’t know and more quality research is needed.

Which UPFs are definitely bad for our health?

The evidence that eating too much fat, sugar and salt leads to poorer health outcomes is well-established, so UPFs that are high in these components can be expected to have the same effect. Other UPFs that are best avoided, or at the very least minimised, are those that undergo extensive formulation and typically include ingredients you wouldn’t find in your own kitchen (including emulsifiers, preservatives, colours and flavours). These products tend to lack protein, fibre, vitamins and minerals as well as protective plant compounds. Examples include (but are not limited to) energy drinks and soda, candy, reformulated potato snacks, powdered soups and instant foods, like noodles.

Of course, the overall balance of your diet is the most important factor, and – even if there’s the odd UPF you can’t give up – a focus on healthy foods should outweigh the risk.

Which UPFs, when eaten in moderation, can form part of a balanced diet?

Although categorised as UPFs, there are some foods that may bestow a health benefit to the consumer, justifying their place in a varied, balanced diet. Jars of pasta sauce and certain breakfast cereals, provided they’re high fibre and low sugar, are worth checking out – see if you can find brands with minimal additives.

These foods can, for some people, make it easier and more convenient to eat healthily because they are time-saving, shelf-stable and – in the case of a sauce – facilitate the inclusion of fresh ingredients, like vegetables. In fact in 2023, one study went so far as to suggest that a diet that obtained most of its energy from UPFs may still achieve a high diet quality score and provide adequate amounts of most macro- and micronutrients.

Are any UPFs beneficial to health?

It’s important to remember that not all processing is detrimental: some processes (such as pasteurisation, fortification and fermentation) can improve the safety of food, enhance its nutritional quality and improve nutrient availability. This means that some UPFs (including fortified foods like plant-based milks and breakfast cereals, as well as gluten-free products and functional foods like yogurts with added plant sterols) can make a valid contribution to a balanced, varied diet for some people, and especially so for those on a restricted diet or with a specific medical need.

How can I navigate the food aisles?

The science around food isn’t black and white, and communicating this nuance can be difficult. This is particularly the case with UPFs, where it’s tricky to even decide what defines them. The potential benefits of UPFs include the increased ease and speed of preparing meals and a reduction in food waste due to longer shelf life. That said, none of us should be in any doubt that the foods most beneficial to health are whole foods and minimally processed fruit and vegetables. While these should constitute the majority of our diet, processed foods and some UPFs can be of value too. Infant and baby formula, innovative products that meet a medical need (such as gluten-free products), and fortified foods that help give a nutritional boost to those following restricted diets are all classed as UPFs, but can all be said to provide health benefits.

Without question, there are many UPFs that are problematic – being high in ingredients we should limit, and low in those that provide valuable nutrition. But it is important to remember that, just because a food is industrially produced, this alone does not class it as a UPF, or even make it an unhealthy option. For now, while the evidence is still coming in (and while there’s little consensus on a definition of UPF), we need to consider the “healthiness” of a food not by the number of ingredients it contains, the number of processes it has been subjected to, or whether it has been made in a domestic kitchen or an industrial plant, but on its overall merits to us, particularly its nutritional contribution to our diet as a whole.

The best way to do this is to make informed choices – this means understanding food labels, cooking from scratch as often as possible and focusing on a balanced and varied diet. By doing so, it is possible to accommodate the convenience of some UPFs (as currently defined), alongside a plentiful array of nutritious, whole foods.