It would be easy to fast until you get hungry, then eat.
That’s the point.
Fasting teaches us through pain of hunger what fortitude is required to avoid the easy-outs of sin or laziness when discipleship gets hard. Fasting trains the physical body how to succumb to the will of the mind. This is the same process the spirit must learn to submit and choose to honor your covenants and promises.
And in the end, we are more attuned, more focused, and more grateful for the blessings of those very covenants and promises.