Although meat is a valuable source of protein and essential micronutrients for humans, red (beef, pork, lamb, goat) and particularly processed meat excessive consumption has been associated with the development of several chronic diseases, particularly colorectal cancer. Nutritional epidemiology pointed out this association about 30 years ago. From there, preclinical and mechanistic studies have consolidated this association, highlighting the role of heme iron-induced luminal lipid peroxidation, nitroso-compound formation, thermally induced neo-formed products and the likely implication of gut microbiota alteration. From these studies, preventive strategies have been developed to counteract the deleterious effect associated with red and processed meat intake. This article describes the major results provided by nutritional epidemiology, preclinical and mechanistic studies and the development of biomarkers linking these studies.