Without animal protein, it is very likely that we would not be as we are -since the last 200,000 years- as indicated by the archeological remains of the hominids that preceded us. Supported by documentary information with abundant bibliography, the dilemma of eating meat is analyzed, with arguments from philosophy, ethics, anthropology, animal welfare science, applied ethology, nutrition, psychology and sustainability. The main objective of this essay is to provide a framework on the use of contemporary ethical principles and theories on our relationship with food animals - such as teleological theories, deontological theories and principlism, among others - that the reader - especially a zootechnical student - can understand as an acquisition of instrumental competences, and apply it to the dilemma caused by the consumption of animal protein.