Actually the text doesn't say Jesus ate anything at all. Saying so is just eisogetical.
John 21:1–14 (NASB95)
1 After these things Jesus manifested Himself again to the disciples at the Sea of Tiberias, and He manifested Himself in this way.
2 Simon Peter, and Thomas called Didymus, and Nathanael of Cana in Galilee, and the sons of Zebedee, and two others of His disciples were together.
3 Simon Peter *said to them, “I am going fishing.” They *said to him, “We will also come with you.” They went out and got into the boat; and that night they caught nothing.
4 But when the day was now breaking, Jesus stood on the beach; yet the disciples did not know that it was Jesus.
5 So Jesus *said to them, “Children, you do not have any fish, do you?” They answered Him, “No.”
6 And He said to them, “Cast the net on the right-hand side of the boat and you will find a catch.” So they cast, and then they were not able to haul it in because of the great number of fish.
7 Therefore that disciple whom Jesus loved *said to Peter, “It is the Lord.” So when Simon Peter heard that it was the Lord, he put his outer garment on (for he was stripped for work), and threw himself into the sea.
8 But the other disciples came in the little boat, for they were not far from the land, but about one hundred yards away, dragging the net full of fish.
9 So when they got out on the land, they *saw a charcoal fire already laid and fish placed on it, and bread.
10 Jesus *said to them, “Bring some of the fish which you have now caught.”
11 Simon Peter went up and drew the net to land, full of large fish, a hundred and fifty-three; and although there were so many, the net was not torn.
12 Jesus *said to them, “Come and have breakfast.” None of the disciples ventured to question Him, “Who are You?” knowing that it was the Lord.
13 Jesus *came and *took the bread and *gave it to them, and the fish likewise.
14 This is now the third time that Jesus was manifested to the disciples, after He was raised from the dead.