Maimonides, the Jewish philosopher and legal codifier, who was also court physician to the Muslim sultan Saladin in the twelfth century, understands the dietary laws chiefly as a means of keeping the body healthy. He argued that the meat of the forbidden animals, birds, and fish is unwholesome and indigestible. According to Maimonides, at first glance, this does not apply to pork, which does not appear to be harmful. Yet, Maimonides observes, the pig is a filthy animal and if swine were used for food, marketplaces and even houses would be dirtier than latrines
The cultural materialistic anthropologist Marvin Harris thinks that the main reason for prohibiting consumption of pork was ecological-economical. Pigs require water and shady woods with seeds, but those conditions are scarce in Israel and the Middle East. They cannot forage grass like ruminants. Instead, they compete with humans for expensive grain. Unlike many other forms of livestock, pigs are omnivorous scavengers, eating virtually anything they come across, including carrion and refuse. This was deemed unclean, hence a Middle Eastern society keeping large stocks of pigs would destroy their ecosystem. Harris points out how, while the Hebrews are also forbidden to eat camels and fish without scales, Arab nomads couldn't afford to starve in the desert whilst having camels around.
These are basically the arguments for vegetarianism.
No, they are arguments for eatings ruminants. Science already showed that humans can't survive on vegetables alone (
).