Ultra-processed foods (UPFs) are defined by the UN’s FAO as “formulations of ingredients, mostly of exclusive industrial use, typically created by a series of industrial techniques”. They form the most harmful subgroup of the NOVA classification, which categorises foods according to the extent of their industrial processing. This subgroup is characterised as having undergone multiple production stages and containing cosmetic additives with “no or rare culinary use” that enhance hyper-palatability. These foods often have a high glycaemic impact and low satiety, leading to overconsumption and contributing to nutritional deficiencies. Moreover, research has found that diets high in UPFs are associated with cancer, metabolic, cardiovascular, gastrointestinal, and respiratory diseases, as well as overall higher rates of mortality.
The NOVA framework has been influential in highlighting the presence of UPFs in modern diets, but the system does not account for the individual nutritional value of food products. The UPF category is highly heterogeneous, grouping relatively healthy items such as baked beans and gluten-free foods alongside traditional junk foods that have undergone similar stages of production. As a result, it becomes difficult to accurately interpret a product’s individual nutritional profile. In some cases, simply containing five or more ingredients can place a food product at risk of being classified as ultra-processed, regardless of its actual nutritional value.
Furthermore, many forms of industrial processing can improve the nutritional quality or accessibility of foods. Nutritional fortification, for instance, can enhance the micronutrient content of products, while allergen-friendly processing can make foods suitable for individuals with specific dietary requirements. Despite these benefits, such processes can still lead to foods being categorised as ultra-processed. Even elements such as appealing packaging have been considered determinants of processing within the NOVA framework, despite having no relevance to the nutritional value of the food itself. Confusion is further compounded by the fact that foods high in salt or sugar are sometimes incorrectly labelled as UPFs, when the health concern in these cases stems from the ingredients rather than the degree of processing.
Despite these limitations, concerns surrounding certain types of ultra-processed foods remain valid. Foods that are energy-dense, low in satiety, and rich in additives with little nutritional value can contribute to unhealthy dietary patterns and adverse health outcomes. However, the current classification system fails to distinguish between foods whose nutritional profile has been improved through processing and those that are nutritionally poor. This lack of nuance presents challenges for consumers attempting to make informed dietary choices and for health professionals providing nutritional guidance.
Vegans are often criticised for higher consumption of UPFs, although relatively few studies directly compare plant-based and omnivorous consumption patterns. Consumption of ultra-processed foods in the United Kingdom is generally high across the population and may appear higher among vegans. However, this observation must be interpreted cautiously because the NOVA classification does not differentiate between processing that improves a food’s nutritional profile and processing that reduces nutritional quality. In many plant-based foods, processing may involve fortification or reformulation intended to meet specific nutritional requirements.
Vitamin B12 provides a clear example of this issue. Fortification with B12 is widely considered a stage of processing necessary for many plant-based foods, and such fortification can contribute to these foods being labelled as ultra-processed. Yet most animals raised for meat, dairy, and poultry products are supplemented with or injected with vitamin B12 during their lives. Consequently, both omnivorous and plant-based food products may ultimately provide comparable levels of this nutrient. Under the NOVA classification, however, the plant-based food is more likely to be penalised as ultra-processed, while the animal-derived product is not categorised in the same way.
The concept of ultra-processed foods has been valuable in drawing attention to the potential health risks associated with highly industrialised food systems. However, the NOVA classification system on which the concept relies does not adequately account for the nutritional quality of individual foods or the potential benefits of certain forms of processing. By grouping nutritionally diverse products into a single category, the framework risks oversimplifying complex dietary realities. This limitation becomes particularly evident in discussions of plant-based diets, where foods may be labelled as ultra-processed despite being nutritionally fortified or otherwise improved through processing. As a result, criticisms of vegan diets for higher UPF consumption may be based on a classification system that fails to distinguish between harmful processing and nutritionally beneficial processing. A more nuanced approach to food classification is therefore necessary to ensure fairer assessments of dietary patterns and to support clearer, more accurate nutritional guidance.