Processed foods are often confused with ultra-processed foods. The latter are simply foods with poor nutrient density and are wrongly considered to be the same thing.

Processed foods are often considered equally harmful to health because they are often lacking in nutrients, similar to ultra-processed foods. However, there is a fundamental difference between the two. While processed foods undergo minimal transformations to improve conservation or safety, ultra-processed foods are subjected to intensive industrial processes that profoundly alter their composition.

The NOVA classification

To clarify this distinction, the NOVA classification system categorises foods into four groups according to their level of processing. Group 4 ultra-processed foods are industrial formulations containing numerous artificial ingredients and additives, often without a recognisable food structure. These products are characterised by a long shelf life and high palatability and are designed to encourage excessive consumption, which can lead to nutritional imbalances and metabolic problems.

Ultra-Processed Foods and Health

The impact of ultra-processed foods on human health is a topic that is increasingly at the centre of scientific debate. One of the most concerning aspects is their effect on intestinal health. Research has shown that these foods alter the intestinal microbiota, reducing its diversity and favouring the proliferation of pro-inflammatory bacteria at the expense of beneficial species such as Akkermansia muciniphila and Faecalibacterium prausnitzii. The presence of emulsifiers, artificial sweeteners, and other additives compromises the integrity of the intestinal barrier, increasing its permeability and promoting chronic inflammation, which is associated with metabolic diseases and gastrointestinal disorders.

In addition to their impact on the microbiota, ultra-processed foods have been linked to an elevated risk of obesity-related cancers. Epidemiological studies indicate that regular consumption of these products is associated with an increased risk of developing certain types of cancer, including colorectal, breast, and pancreatic cancer. This effect could be due not only to excess calories and subsequent weight gain but also to exposure to harmful compounds generated during industrial processing, such as polycyclic aromatic hydrocarbons, acrylamide and nitrosamines. Furthermore, the presence of endocrine-disrupting substances, such as bisphenol A and certain phthalates, can negatively impact hormonal regulation and promote the development of hormone-dependent tumours.

The critical issues of the NOVA classification

Despite this evidence, the NOVA method has some critical issues. While it is useful for identifying potentially problematic food categories, it is not always applied rigorously. The definition of ultra-processed food is based on quantitative rather than qualitative criteria, which can lead to ambiguous classifications. For instance, some traditional foods may be erroneously categorised as ultra-processed based solely on the number of ingredients without considering their actual nutritional profile. Furthermore, the NOVA method does not distinguish between safe and potentially harmful additives, grouping products with very different health impacts together.

An example of this imprecision is Italian cured meats, which do not fall into the hyper-processed food category. Traditional Italian cured meats are obtained through controlled transformation processes such as seasoning and salting, which do not alter the basic properties of the food matrix and maintain a balanced nutritional profile. They are prepared using simple ingredients and do not contain large quantities of artificial substances that characterise true ultra-processed foods.

Food processing is not in itself harmful

It should also be emphasised that food processing itself is not harmful. Techniques such as fermentation, cooking and preservation improve food safety, extend shelf life and facilitate access to nutritious foods. However, excessive processing can destroy the organic matrix of foods, thereby compromising the bioavailability of essential nutrients. Adding exogenous and synthetic substances, such as artificial flavours, emulsifiers and sweeteners, worsens the situation further, creating products that alter the metabolic response and encourage excessive consumption.

Ultimately, the excess consumption of ultra-processed foods poses a tangible health risk, particularly to the intestinal microbiota and increases the risk of cancer. However, the NOVA classification system requires greater precision to categorise foods accurately. A more accurate evaluation, integrating nutritional parameters and data on metabolic effects, could help to provide more reliable, science-based dietary guidelines.