Fasting never saved anyone, unless you are fasting so someone else can find salvation.
Fasting is a discipline, part of the process of reigning in the passions so we can train ourselves to more easily say no to temptations. It is akin to an athlete training. Who do you think runs the race to the end? The athlete who makes no effort to build his stamina and strength or the one who struggles and strives to be better than he was the day before?
1 Corinthians 9:24-25
Do you not know that in a race all the runners compete, but only one receives the prize? So run that you may obtain it. Every athlete exercises self-control in all things. They do it to receive a perishable wreath, but we an imperishable.
2 Timothy 4:6-8
For I am already on the point of being sacrificed; the time of my departure has come. I have fought the good fight, I have finished the race, I have kept the faith. Henceforth there is laid up for me the crown of righteousness, which the Lord, the righteous judge, will award to me on that Day, and not only to me but also to all who have loved his appearing.
Hebrews 12:1-2
Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with perseverance the race that is set before us, looking to Jesus the pioneer and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of the throne of God.
We are called to be holy, and the Holy Orthodox Church provides the tools by which we can grow in holiness. Fasting is just one of those tools. What do the Protestant Churches provide?