According to a 2012 Gallup poll, 5% of Americans consider themselves vegetarians. That number may be small, but the number of actual vegetarians in this country may actually be smaller. According to a 2011 Psychology Today article, many who claim to be aren't completely vegetarian, but rather are people who follow a "vegetarian-inclined diet." A 2003 USDA study highlighted in the article confirms that "self-defined" vegetarians may still eat meat, but they eat less of it and are generally considered healthier than the general population.
Even if their numbers are comparatively small, vegetarianism is not a new phenomenon. In fact, anthropologists believe that many of our ancestors were vegetarians, eating nuts, fruit and ancient fungus. While it was previously thought that Neanderthals ate mostly meat, a 2012 science journal article explains that plant-material accounted for large portion of their diet. Sure, our human forebears ate meat on occasion, but it was often difficult and dangerous to catch. So, they relied on non-moving food (vegetation) as sustenance. That's not to say that humans had no need for meat. A 2012 study concluded, based on the studying of skulls, that human evolution could have only happened with a high-energy diet, one that could have not been maintained by plants alone. A 2016 report in Nature confirmed that humans needed meat to evolve. In other words, as one researcher put it, "I know this will sound awful to vegetarians, but meat made us human."
4000 years ago, humans began making the choice not to eat meat. Ancient Egyptians' diet, according to a recent finding, relied mostly on cultivated wheat and barley rather than meat and fish. This might be surprising considering the civilization's proximity to the Nile, but researchers theorize this was for religious reasons. Cows, rams, pigs and geese were all considered sacred in ancient Egypt. Not only did Egyptians at the time rarely eat meat (only during festivals and special occasions), they also frowned upon the wearing of animal flesh.