Is this the manner of fasting I wish,
of keeping a day of penance:
That a man bow his head like a reed
and lie in sackcloth and ashes?
Do you call this a fast,
a day acceptable to the LORD?
This, rather, is the fasting that I wish:
releasing those bound unjustly,
untying the thongs of the yoke;
Setting free the oppressed,
breaking every yoke;
Sharing your bread with the hungry,
sheltering the oppressed and the homeless;
Clothing the naked when you see them,
and not turning your back on your own.
Then your light shall break forth like the dawn,
and your wound shall quickly be healed;
Your vindication shall go before you,
and the glory of the LORD shall be your rear guard.
Fasting is no end in itself. It should only serve to break our selfishness that we might be less violent and more tuned in to the needs of the world. Fasting to any other end is vainglory.
There are lots of things we can fast from classics like chocolate and beer to other things our imaginations feed upon like the internet and CNN. The trick is to choose not the one that seems the most religious, but the one that will make our hearts less selfish, setting us up to contribute to the justice and peace of the world.