This is a great question. The title "of Star Food" really gets to the heart of the matter. Let me try to explain.
Dade's father is a practical man. He lives for the store and his family. He works hard and commits to his business with his whole heart.
Dade's mother, on the other hand, is the complete opposite. She is a dreamer. And she wants Dade to dream as well. This is why she encourages him to look up into the sky to get inspiration and insight, so that he will be man of "limited fame." She wants him to see extraordinary things in common things. She gives the example of Leonardo da Vinci and Thomas Edison.
Dade, therefore, is between his mother and father, which brings us to the title of short story. Star food is the name of the grocery store. So, he is like his father. He gazes up into the stars. In this way he is like his mother. He is on the roof of the store. So, he is like his mother, but he is still on the store, which means he is like his father.
He is in between.