And, very importantly, as brother StuartK put it, we have to remember why we fast.
Toward that end it is beneficial to read Isaiah 58:5-9a:
Is such the fast that I choose,
a day to humble oneself?
Is it to bow down the head like a bulrush,
and to lie in sackcloth and ashes?
Will you call this a fast,
a day acceptable to the LORD?
6Is not this the fast that I choose:
to loose the bonds of injustice,
to undo the thongs of the yoke,
to let the oppressed go free,
and to break every yoke?
7Is it not to share your bread with the hungry
and to bring the homeless poor into your house;
when you see the naked, to cover them
and to not hide yourself from your own kin?
8Then shall your light break forth like the dawn,
and your healing shall spring up quickly;
your vindicator shall go before you,
the glory of the LORD shall be your rear guard.
9Then you shall call, and the LORD will answer;
you shall cry for help, and he will say, Here I am.