Important to differentiate between food processing and formulation

The concept of ultra-processed foods (UPFs) is defined by the NOVA classification system, developed by the Brazilian researcher Carlos Monteiro (Monteiro et al., 2019). However, the definition is controversial and widely debated (e.g., Louie et al., 2025; Mela D et al., 2026). One criticism is that the associations between so-called ultra-processed foods and various negative health outcomes have mostly been observed in observational studies. For these associations to be considered credible as causal relationships, they need to be supported by a biologically plausible mechanism—in this case, a mechanism that serves as a common denominator for the group of ultra-processed foods. So far, no such mechanism has been established.

Formulation, not processing, explains many proposed mechanisms

Several mechanisms have been proposed, with varying relevance for the different types of foods classified as ultra-processed. These often highlight well-known negative health effects of salt, free sugars, saturated fat, and high energy content. However, a food’s content of these substances, as well as their energy content, often depends primarily on ingredient choices, rather than the processing. A food can also be classified as ultra-processed because it contains what NOVA calls cosmetic additives. Again, this is more about the food’s formulation than how it was processed. In other words, despite the name, the discussion about so-called ultra-processed foods is not always about processing.

Formulering vs processning 

In food technology, a distinction is made between formulation and processing of a food product. Formulation refers to the combination and design of ingredients to create a specific product, whereas processing involves subjecting raw materials or the composite food to physical or chemical treatments to achieve desired characteristics. Both formulation and processing can affect the nutritional content and health properties of a food, but their relative importance can vary considerably depending on the product type and the specific food attribute or health impact of interest.

Processing may play a significant role

In some cases, processing can have a significant impact. For example, certain vitamins can be degraded by heat, and minerals can leach out during boiling. Processing can also affect the bioavailability of nutrients, i.e., their availability for absorption by the body, by breaking down or reorganizing structures. Two foods with the same formulation, and thus similar nutrient content, can therefore have different health properties if they are processed differently. For instance, white bread elicits a high postprandial blood glucose response, whereas pasta produces a lower response due to structures formed during pasta extrusion (Di Pede et al., 2021). Another example is that the absorption of beta-carotene from carrots is higher in grated, pureed, or cooked carrots, where cell structures are broken down, compared to whole raw carrots (Hedrén et al., 2002).

These are just a few of countless examples illustrating when food processing matters for health. In other words, we need to remain humble about the importance of processing and strive to understand how different processing techniques lead to positive or negative changes in a food’s composition and health properties. At the same time, we also need to recognize what effects are not due to processing.

In some cases, formulation has a greater Impact

When it comes to the amounts of saturated fat, salt, and/or free sugars in products such as breakfast cereals, bread, sausages, cookies, ice cream, and soft drinks, the issue is primarily one of formulation. In other words, the quantity of fat, free sugar, and salt, or raw materials containing these components, in the recipe plays a major role. Processing, such as baking cookies or stuffing sausages, is unlikely to significantly alter the content or bioavailability of saturated fat, free sugar, or salt. There is broad agreement that intake of saturated fat, free sugars, and salt should be limited—but the solution does not necessarily lie in reducing processing. In some cases, it may even be the opposite: new, innovative processing methods can enable the reformulation of foods into appealing products with a healthier nutritional profile.

IUFoST proposes an alternative model

The lack of distinction between formulation and processing in discussions about ultra-processed foods is an issue that engages, among others, the International Union of Food Science and Technology (IUFoST). Within IUFoST, a working group has developed a method called the “IUFoST Formulation and Processing Classification” (IF&PC) (Ahrné et al., 2025). One key reason for IUFoST to develop this system is precisely to address the current conflation of formulation (composition) and processing, thereby contributing to the improvement and refinement of the controversial NOVA classification system.

For quantifying nutritional value, this model uses the Nutrition Rich Food (NRF) nutrient density index, which is also used in research at RISE (Bianchi et al., 2020; Strid et al., 2021). The model also aims to explore the possibility of taking other important food attributes into account for product classification, such as safety, sustainability, palatability, affordability, and convenience. The researchers behind the IUFoST initiative propose that the model be further developed and complemented through coordinated research and development efforts among food scientists, food engineers, and nutritionists (Ahrné et al., 2025).

Global framework for revised food classification

IUFoST has also recently introduced a new global framework, “Towards Evidence-Based, Inclusive and Science-Driven Food Classification Systems”, aimed at transforming how foods are classified in policy and public health discussions. The initiative rests on three pillars: developing evidence-based classification methods, engaging with global policy platforms such as the Codex Alimentarius Commission, and improving public understanding of the benefits of food processing. Through collaboration with FAO, WHO, the International Union of Nutritional Sciences (IUNS), and other partners, IUFoST aims to ensure that future food policies are grounded in robust science.

Eating rate a key determinant

Regarding possible mechanisms behind the health effects of so-called ultra-processed foods, a recent study from the RESTRUCTURE project investigated the role of eating rate. Previous research has shown that the speed at which we eat affects how quickly we feel full, which in turn influences how much food we consume during a meal. The RESTRUCTURE study examined the longer-term effects of meal texture and eating rate on energy intake from meals composed of foods classified as ultra-processed, with textures that either allowed faster or slower consumption (Forde et al., 2025).

The study found that individuals who consumed foods with textures that forced them to eat more slowly consumed on average about 370 kcal less per day compared to when they ate foods with textures that allowed faster intake. This effect persisted over the study’s two-week period, during which body fat also decreased slightly in those consuming the “slower” foods. The findings highlight the importance of food texture in regulating eating rate and the central role of sensory cues in controlling meal size. The study also demonstrates that not all foods falling under NOVA’s definition of ultra-processed foods should be treated the same.

References

Ahrné L, et al. Defining the role of processing in food classification systems-the IUFoST formulation & processing approach. NPJ Sci Food 2025;9:51.

Bianchi M, et al. Systematic Evaluation of Nutrition Indicators for Use within Food LCA Studies. Sustainability 2020; 12: 8992. 

Forde CG, et al. Eating rate has sustained effects on energy intake from ultraprocessed diets: a 2-week ad libitum dietary randomized controlled crossover trial, Am J Clin Nutr 2025: 101122.

Di Pede G, et al. Glycemic Index Values of Pasta Products: An Overview. Foods 2021; 10: 2541.

Hedrén E, et al. Estimation of carotenoid accessibility from carrots determined by an in vitro digestion method. Eur J Clin Nutr. 2002; 56: 425-30. 

Louie JCY. Are all ultra-processed foods bad? A critical review of the NOVA classification system. Proceedings of the Nutrition Society. 2025: 1-9.

Mela D. Misleading narrative of “healthy” ultra-processed foods. BMJ 2026; 392: e087538.

Monterio, CA, et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutrition 2019; 22:936–94. 

Strid A, et al. Diets benefiting health and climate relate to longevity in northern Sweden. Am J Clin Nutr 2021; 114: 515-529.