Human food vs. animal feed debate. A thorough analysis of environmental footprints

Currently, a large portion of grain production is funneled into animal feed despite widespread hunger and undernutrition. In the present work we: (i) estimated the area, water and carbon footprints of animal-source proteins (AP) obtained from intensive farming systems and compared them with those from producing an equivalent amount of plant-source proteins (PP); (ii) postulated a set of straightforward hypotheses to recover environmental resources by cutting down a surplus in the per capita protein intake from three representative regions where intensive animal farming systems account for a great share of animal food production.