Fast In Secret

Luke 5:
33 Then they said to Him, Why do the disciples of John fast often and make prayers,
and likewise those of the Pharisees, but Yours eat and drink?
[Apparently the question is being asked on "a fast day".]
34 And He said to them, Can you make the friends of the bridegroom fast while the
bridegroom is with them?
35 But the days will come when the bridegroom will be taken away from them;
then they will fast in those days.

A right and a wrong way to fast and pray.
Matthew 6:
16 Moreover, when you fast, do not be like the hypocrites, with a sad countenance.
For they disfigure their faces that they may appear to men to be fasting. Assuredly,
I say to you, they have their reward.
17 But you, when you fast, anoint your head and wash your face,
18 so that you do not appear to men to be fasting, but to your Father who is in the secret;
and your Father who sees in secret will reward you openly.

How does the reward of prayer and fasting "manifest openly"?
Is it not in the fruit of the Spirit?