Response to: Debate in relation to "Ultra‑processed foods and human health: the main thesis and the evidence".

Abstract

This response addresses criticisms by Ibsen and colleagues regarding the definition of ultra-processed foods (UPFs) by Nova, proposed mechanisms linking UPFs to health outcomes, and the choice of comparators in epidemiological studies. We argue that these critiques partially reflect a misunderstanding of Nova and how evidence on UPF has been generated. Nova classifies foods into four groups by the extent and purpose of industrial processing, not nutrient composition. Epidemiological studies primarily examine the health effects of the worldwide increasing exposure to the ultra-processed dietary pattern, capturing real-world dietary displacement of the first three Nova groups, the basis of traditional healthy diets, by UPFs. The focus on specific food nutrient imbalances has informed important policies. However, this approach is insufficient to explain or orient actions to reverse the worldwide rise in diet-related chronic diseases, because they fail to address the underlying industrial food system. The ultra-processed dietary pattern is characterized by the systematic co-occurrence of nutrient and non-nutrient harmful attributes, including altered food matrices, excessive energy density, hyper-palatability, additives for which there is evidence of harm, and industrial contaminants. Heterogeneity within this pattern does not invalidate it as a dietary exposure, just as variability within the Mediterranean diet does not preclude its epidemiological and policy relevance. The same applies to the claims that mechanisms linking UPFs to health outcomes are non-specific. Similarly, critiques of inappropriate comparators conflate analyses of individual foods and dietary patterns. Given the scale, consistency, and breadth of the evidence, actions to reduce overall UPF consumption are justified and overdue.