When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full. But when you fast, put oil on your head and wash your face, so that it will not be obvious to men that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.
"Fasting is spiritual concentration. In this case, you are concentrating your mind, soul, and body to know God and to know his will."
Fasting from the world and feasting on God is such an important aspect of our faith. The key to fasting is to listen to what Jesus tells you to do. He might ask you to fast from television for a little bot so that you can spend time talking to Him. Whatever He calls you to do, do with all your heart. However, do not advertise the fact that you are fasting. Keep it between you and God. Allow Him to work in and through you. If you are going to fast from food, please consult your doctor or parents to make sure that it is the healthiest and wisest choice for you. Also, please note that fasting is not a way to lose weight. Many people fast as a way of dieting. But, in reality, when you fast, your metabolism stops functioning and you are not burning calories. Your heart needs to be in the right place to fast from anything--not on losing weight.