Abstract The ultra‐processed food (UPF) concept first emerged 15 years ago, and is now studied worldwide in different contexts, for example, human health, food behavior, socio‐economic, food consumption, food scoring, and food system sustainability. Briefly, UPFs are defined as containing at least one marker of ultra‐processing (MUP). MUPs are (1) cosmetic additives, (2) aromas, (3) some highly processed carbohydrates, proteins, fats, and/or fiber, and (4) drastic processes directly applied to food such as extrusion cooking or puffing. The first three categories of MUPs are on the food packaging in the list of ingredients, and are extracted, then purified, from raw foods or coming from artificial syntheses, leading to a‐matrix/a‐cellular compounds. Therefore, the core paradigm to define MUP is extreme food matrix degradation , and for UPF, matrix artificialization . Besides, UPFs are more than just junk food, encompassing numerous industrialized foods, falsely presented as healthy, for example, animal‐based food analogs, but also organic, vegan, gluten‐free, micronutrient‐enriched, and/or light foods. In this way, UPFs are “high‐quality junk foods.” Otherwise, UPF being a holistic and indivisible concept by essence, we propose in this review to analyze ultra‐processing at four holistic levels corresponding to four important scientific issues: the food matrix, the dietary pattern, food system, and food scoring. We reached the main conclusion that UPFs should be first studied with a holistic and scientifically based approach, not a reductionist one. Otherwise, we take the risk of performing greenwashing and create still more new health threats at a global level.