Isn't it natural to eat animals, since our ancestors did?
2. There's no question that in the past, during war or famine, eating meat helped insure survival.
Even now in certain parts of the world - cattle, fish and poultry, help insure survival in rural population where marginal lands don't support the growing of agriculture - but can still support the grazing of livestock; as well as coastal regions that have insufficient space for growing but access to fish.
With all of the above noted, few people in developed countries can claim that their survival depends on animal products.
In terms of its nutritional value - there is nothing in animal products, that cannot be found in a well-balanced vegan diet.
With a thought to the environment and sustainability -we should stop feeding a huge portion of granis to livestock (which = huge food waste), and instead focus on growing grains for human consumption instead.
"Did you know that factory farming now accounts for more than 99% of all farm animals raised and slaughtered in the United States? Did you also know that it is one of the leading contributing factors to global warming?"
Something to think about, via: http://globalsolutionspgh.org/2014/04/global-warming-factory-farms/