During the past decades, diets have shifted towards an important increase in the degree of food processing and formulation. “Ultra-processed foods” (UPF) now represent more than 50 % of energy intakes in several Western countries. In the very last years, an impressive accumulation of evidence from large-scale epidemiological studies linked regular UPF consumption to diverse adverse health outcomes. In this framework, our team conducted pioneer studies within the prospective e-cohort NutriNet-Santé (n=170,000) launched in 2009 in France. Dietary intakes were collected using repeated and validated 24-hour dietary records, covering>3500food items, which have been categorized using the NOVA classification according to their degree of processing. These analyses highlighted robust significant associations between the consumption of UPF and increased risks of overall and breast cancers (Fiolet BMJ 2018), cardio/cerebrovascular diseases (Srour BMJ 2019), mortality (Schnabel JAMA Int Med 2018), type 2-diabetes (Srour JAMA Int Med 2019), overweight, obesity and weight gain (under review), depressive symptoms (Adjibade BMC Med 2019), and gastro-intestinal disorders (Schnabel AJG 2018). A large number of lifestyle, socio-demographic, anthropometric, medical, behavioral, and nutritional factors were accounted for. Research perspectives now consist in elucidating the potential mechanisms that underlie these associations, notably involving nutritional quality but also various factors such as cocktails of food additives, neoformed compounds created during processes or packaging materials in contact with food. Meanwhile, public health authorities in several countries have recently started to promote unprocessed or minimally processed foods and to recommend limiting the consumption of ultra-processed foods.