Veganism: to eat no meat either out of necessity and/or ethical objection and/or because of a conscious "simple living" strategy and/or out of the belief that the consumption of meat is economically unsound in terms of water usage, green house gas emissions, energy consumption, animal waste.
The alternatives are: plant-based meat substitutes (based on: soy, rice, peas-proteins, mushroom), cultured meat from in vitro-grown muscle tissue (although there are still numerous technological obstacles that have to be overcome to produce in vitro meat) or Entomophagy (insects as food could serve as a more environmentally friendly source of dietary protein).