I don't think it's any mystery that someone who eats meat 2 0r 3 times every day would almost immediately feel better not eating meat after 3-4 days.
do some kind of colon cleanse, and you'll see how healthy you really are.
most meat eaters have colons filled with pounds of rotting undigested meat - something that is obviously not healthy, and occurs because meat is more difficult to digest. the typical american diet is meat at every meal, which is not balanced. for me, eating beef once a month or every couple of months is a shock to my system unless it's in small quantities - it takes several days to digest. you're supposed to poop once for each meal you eat, which is an excellent sign of how healthy your digestive system is...