Warbler said:

how can you give up all food ? If you did that for the entire season of lent, you'd die.

Actually, probably not. Lent is based off of Jesus' temptation in the desert, which lasted forty days, during this time he did not eat. While many would be quick to say "Aw, come on! The Bible is clearly a work of fiction/Jesus was the son of God, he could do things a normal man couldn't!" I actually had a friend who felt the same way, he was talking with one of his Christian friends about how ridiculous the whole thing was and that he was sure it was impossible, his friend's response was, "I guess the only way to know for sure would be to try." To this he responded, "I think I will." And he did. He found it so fullfilling that after the first time he made it an annual thing. He said the first four days are the most difficult part (which, having gone a few more days than that myself, I can confirm), and that after a bit it gets to the point you don't even feel hungry anymore, with an occasional exception. So yeah, you could do the entire period of lent without eating and live to tell about it, if you're in fairly good health. It isn't really very good for you though, as somewhere in that period of time your body will start to harvest itself for nutrition...