Actually alot of Catholics in the past didn't't believe in eating meat during all of Lent. Which is a commemoration of Passover in a sense where the Jews escaping from Egypt had only flatbread to eat on thier exodus. So Lent is a 40 day period of "fasting" starting on the day after Mardis Gras or Fat Tuesday. Which is why there is a huge party, you know the last day before Lent they used to have a big feast which as now turned into getting smashed. The 40 days lasts through Easter. These days most Catholics I know just give up one of thier vices such as alcohol, chocolate, sex, whatever they think they should go without for Lent.