Confusion often arises when discussing or considering ultra-processed foods because the term itself is not uniformly defined or understood across different scientific and regulatory bodies. The NOVA classification was first proposed in 2010 by nutritionist Carlos Augusto Monteiro at the University of São Paulo and colleagues from other Brazilian institutes. But its implementation is sometimes described as complex and subjective, causing discrepancies in what is deemed ultra-processed.
Source: Navigating ultra-processed foods: getting clarity on complexity – EIT Food