Fasting is not the most popular of Spiritual Practices – maybe because we enjoy comfort, maybe because we are simply lazy, maybe because we think we have deep theological objections to fasting; whatever the reason most of us simply do not fast.
Yet we read the words of Jesus that tell us when we fast not to make a show of it, like hypocrites do. Note Jesus does not say ‘if you’ fast, but when you fast. (Matthew 6:16-18)
A fast is disciplined diet, not going without food entirely. During a fast, you still eat; you just abstain from certain foodstuffs. Traditionally, people have fasted by eliminating luxury items from their diets, such as meats. For example you could have a fast that consists of eating whatever you want, but drinking only water.
The simplest way to fast is to just omit an item or two from your regular diet—something that you would normally eat in the course of the day. Every time you get an appetite for those items, you will be reminded of your fast and that will remind you of the reason for your fast, and you can pray instead of eating. This can have immense spiritual benefit. You are simply using your belly as a spiritual alarm clock.
Another way would be to chose a day in the week when you decide to fast during lunch – by all means have a 
glass of water, but use the time normally set aside for eating to prayer and reading God’s word.
Fasting is helpful in that it reveals the things that control us. Too often we cover up what is inside of us with food and other good things, but in fasting these kinds of things come to the surface. One thing we learn from fasting is our lust for good feelings. If we are hungry, we don’t feel good, and soon we realise that we would do just about anything to feel good. Now there is nothing wrong with feeling good, but that has to be brought into a place in our lives where it does not control us.
Another thing it can bring to light is our weaknesses. When you fast, pray, “Lord, reveal what is inside of me.” And listen without distraction for the answer.