Question: If a vegetarian did not eat meat for a long time, one or two years and then he began eating it again. What will be the consequences?
Answer: Well, karmically he will increase his karma again to where it was before he became a vegetarian. It will put him back in a heavy karma position. He may experience some actual physical problems until he gets used to it again, once his body gets used to the meat again, it will just be normal, so to speak.
But it is an unfortunate turn of events. A person who had already come to a level of being a vegetarian and then going back to eating meat, is just like a person who had been an alcoholic and quits drinking, going back is unfortunate.
Almost without exception, if something like this happens it is due to bad association. You see, so again, association is very important.