Biblical Fasting is Not a Fad, Not Dieting and Not For Show
"And when you fast, do not look gloomy like the the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. But when you fast, anoint your head and wash your face, that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you." - Jesus
Daniel Stood Up for His Faith
"Then Daniel said to the steward whom the chief of the eunuchs had assigned over Daniel, Hananiah, Mishael, and Azariah, "Test your servants for ten days; let us be given vegetables to eat and water to drink. Then let our appearance and the appearance of the youths who eat the king's food be observed by you and deal with your servants according to what you see." So he listened to them in this matter, and tested them for ten days. At the end of the ten days it was seen that they were better in appearance and fatter in flesh than all the youths who ate the king's food."
"And after fasting forty days and forty nights, he was hungry. And the tempter came and said to him, "If you are the Son of God, command these stones to become loaves of bread."
Jesus fasted but He was also tempted after doing so. It is important, while denying oneself of the nourishment and pleasures of this world, to partake of spiritual nourishment which comes from being in the presence of God, and reading and studying God's Word.
Jesus responded to the temptations thrown at Him, with Scriptures.