Matthew 6:18 But when you fast, put oil on your head and wash your face, so that it will not be obvious to others 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.
Have you ever wondered why people wear scarves in the winter. Personally, I have owned or worn one. I thought they were fashion items and despite being an obvious fashion model, I never wore them. Then my wife told me they were to keep your neck warm. I was born and raised in the south. My neck may be red but its never been cold enough to notice. But this year, around Christmas it got Canada cold around here and I understood. The cold was pushing down my neck and into everywhere. People wear scarves for fashion bu they also wear them because they keep you warm: they work.
In the above verse, look beyond the Lord saying we shouldn’t brag about what we do for the Lord. That actually applies to everything. We should have humble spirits. But look past that and see the part about God rewarding you. It works. Fasting leads us to rewards that only God can give us.