Lent isn't about giving up something you love, it's about giving up something that separates you from god. Although, I'm pretty sure most Christians just use it as an excuse to go on a diet (like the people who give up soda).

I think Wikipedia pretty much sums it up in a sentence, "The traditional purpose of Lent is the penitential preparation of the believer—through prayer, penance, repentance, almsgiving, and self-denial."