Fr. Milovan Katanic has an excellent post on understanding the spirit of the fast during Lent:
Let there be no mistake, God will be pleased if we fast with humility and sincerity. The Pharisees once asked the Disciples, “Why is your Teacher eating with tax collectors and sinners?” Jesus overheard them and replied simply, “Go and learn what it means ‘I desire mercy and not a
sacrifice’.” (Matt. 9:13).
Read the rest here: Mercy, not Sacrifice