An excellent article on CatholicExchange.com addresses the great grace-giving gifts we have during this Lenten season of prayer and fasting. Indeed, these two spiritual weapons are two of the greatest in a Catholic's arsenal against sin and the Devil. From the article:
Through fasting we can gain that freedom and a deeper spirituality, a greater hunger for God. It is a tool that helps us obtain a closer walk with God. Through God’s grace it has the power to break the effect of concupiscence — the tendency to sin — and brings our flesh under submission. Prayer and fasting are largely overlooked as weapons to conquer addictions. But if you are struggling with persistent sins such as lust or gluttony, fasting is an effective way to help you rid these sins from your life.
Many Catholics are never taught about the importance and reasoning behind prayer and fasting. In our society, who would even think of denying themselves anything they wanted? If we have food, why not eat it? If we want to spend our time watching TV or browsing the web, why not do that? Lent is a retreat for Catholics—learn to pray (even if it be a simple prayer of faith) and learn to fast (from food and from other things... but be sure to take care of yourself!).