We fast to focus our minds and thoughts on God and God alone.
What purpose is it to fast when God is in your midst, walking and talking with you?
An analogy would be to pine for and miss your spouse and write love letters to her when she's staying in the same house as you (instead of in a faraway land). It would make sense when your wife had to travel away.
Same things for Jesus and fasting.
Tit 3:2 to speak evil of no one, to avoid quarreling, to be gentle, and to show perfect courtesy toward all people.