The purpose of this paper is to present a scientific consideration of the consumption of red meats as it relates to health and to the sustainability of our planet, and to help professionals and consumers to reflect on this matter and make suitable decisions in this respect. An interdependence clearly exists between climate change, our dietary models and our health, and all of this involves various factors. It should be kept in mind that not all types of foods, diets or alimentary patterns have the same environmental impact. The most highly “questioned” foods include intensively produced red meats and processed foods. These types of foods are consumed in larger quantities and with greater frequency in the developed societies, and above all in the most highly urbanised areas. It is known that 22% of the deaths in our world may be attributed to diet (overeating, poor diets or malnutrition) and this obliges us to consider the importance of carefully choosing the foods that we eat, together with the quantities of these foods and the frequency with which we eat them. It should also be recalled that 14% of the greenhouse gases (GHGs) come from livestock and 30% are related to the food system, which explains the great influence of livestock on food sustainability. A balanced diet based on varied foods, above all including those of vegetable origin, is a possible solution for reducing greenhouse gas emissions (per gramme of protein and per calorie ingested). Such a diet is also healthier, helping to reduce the risk of non-communicable chronic illnesses. Progress should be made towards the achievement of environmentally more sustainable livestock management and a careful monitoring of impacts should be carried out, while increasing the production of vegetable foods and their consumption in different fields.