Carnivorousness is a part of human evolutionary heritage, but typical meat intakes were limited in virtually all preindustrial societies. Rising meat consumption has been a key marker of the universal dietary transition that has accompanied economic modernization. Meat is now the largest source of high-quality animal proteins, and in some countries its annual supply is as high as 100 kg or more per capita. At the same time, high average intakes of red meat and poultry have had a number of undesirable agronomic, economic, nutritional, and environmental consequences. Fortunately, most of these negative effects can be alleviated by reducing excessively high meat consumption and by managing better both the production of feeds and the feeding of animals.