Ultra-processed foods: A new holistic paradigm?

The concept of ultra-processed foods (UPFs) is new, and it was proposed for the first time in 2009 as group 4 of the NOVA classification to address the degree of food processing. UPFs include not only "junk foods" but also foods marketed as healthy, such as light, vegan, organic, or gluten-free products. UPFs are characterized by the presence of highly-processed/purified "cosmetic" ingredients and/or additives to restore and/or exacerbate organoleptic properties, i.e., taste, aroma, color and texture. Substantial industrial processing techniques, e.g., puffing, extrusion cooking, and/or extreme fractioning/refining that greatly breakdown the food matrix, may also be markers of ultra-processing. The UPF concept has been consistently criticized for being an overly heterogeneous concept, and the NOVA classification has been criticized for being qualitative only and too imprecise. This review is intended to discuss the UPF concept from a holistic perspective and to analyze the scientific soundness of criticisms about UPFs and NOVA. The UPF concept is first defined; then, its primary nutritional characteristics are described, followed by their association with health based on human studies. UPF criticisms differ between holistic and reductionist perspectives. In a holistic concept, reductionist researchers view the proposed definition of UPF as an imprecise, vague and heterogeneous technological group. However, from a holistic perspective, the UPF concept has serious advantages, such as broad and common deleterious health attributes (i.e., the loss of "matrix" effect, empty calories, poorly satiating, hyperglycemic and containing artificial compounds foreign to the human body).