Eating Lies: the NOVA mystification

With the end of summer, as is customary, the pages of magazines and periodicals fill up with advice on how to shed the extra pounds gained during the holidays. Among the various suggestions, this year one seems to dominate all others in popularity: eliminating ultra-processed products from the diet. The concept seems intuitive, even a matter of common sense, given the frightening name of the category. Scientific evidence, however, tells a different story.

The term “ultra-processed” originates from the NOVA classification, developed by a group of Brazilian researchers in 2009. Unlike traditional nutritional models, which are based on decades upon decades of research and scientific corroboration, NOVA does not regard the nutrient content of a food as decisive—for example, how much sugar, fat or fibre it contains—but focuses instead on its presumed degree of industrial processing. On this basis, foods are divided into four groups, from NOVA 1, devoted to the least processed foods, to NOVA 4, which brings together a range of products labelled “ultra-processed.”

This latter group ends up placing under the same label products such as sugary drinks and confectionery on the one hand, and packaged wholemeal bread or plain yoghurt on the other.

It is precisely this heterogeneity that researchers have identified as the first weakness of the system, because no scientific evidence supports treating foods with radically different nutritional compositions as a single biological category.

But this is only one of the objections that scientific literature has raised against NOVA in recent years. The central issue is that the system is based on categories that are too broad, shaped more by ideological assumptions than by scientific reasoning. The degree of processing, in fact, does not in itself determine the healthiness of a food, while its demonisation follows a form of anti-industry populism that is widespread in Latin America. The very term “ultra-processed” lacks an objective, internationally agreed definition. And even within the NOVA classification, it is unclear what quantitative thresholds establish the distinction between a food belonging to group 3 and one belonging to group 4.

International nutritional guidelines, it should be remembered, have never been based on the degree of industrial processing of a food. It therefore seems surprising that, despite such a fragile scientific foundation, the concept of “ultra-processed” food has gained so much ground in public discourse. Several factors have contributed to this outcome. First and foremost is the term’s journalistic appeal. As the old saying goes, “bad news sells,” and the prefix “ultra,” associated with the manipulation of something as primordial as food, is a guarantee of success for alarmist and sensationalist articles. The use of this expression also taps into widespread distrust of the large food industry, a mistrust fuelled in part by the propaganda of numerous organisations active in the fields of food, the environment and agriculture. Finally, a network of researchers has emerged from South America, fuelling a proliferation of studies linking the consumption of so-called ultra-processed products to various diseases. These studies, almost all of a merely observational nature, are often based on inconsistent data or flawed methodologies and cannot demonstrate a genuine causal relationship.

Returning to a balanced eating routine after the summer, therefore, does not require banning entire categories of products on the basis of their presumed degree of processing, but rather focusing on what has a real and measurable impact on health, such as the balance between calories consumed and expended, dietary variety, the proportion of nutrients and the amount of fibre. The NOVA classification, however widespread it may be, remains an unsuitable tool for guiding individual food choices. Recommending its use as a compass for a healthy diet does nothing more than foster an unjustified sense of guilt among consumers, leading them to give up many products they enjoy without this contributing in any way to improving their health.