I haven't trusted plane food entirely since I got food poisoning from some pizza they gave me on one of my connecting flights home. Then the airline forced us to change our flight. I then threw up in the hotel they had us stay in right before we left and then again on the bus to the hotel. I then threw up several times between flights. I then was sick the entire day and the way home.
I usually fly with Singapore Airlines or Qantas so it isn't too bad. However the head of the food resigned a few years ago with SA and my family find it has gone downhill since then. Qantas seems, on the other hand, to be getting more edible!
I found it pretty good... but anyway it depends. once I flew in first-class (how do you call it? the section with wider seats) because there was overbooking (I don't have enough money to pay an overseas first-class trip xD) and the food was DELICIOUS.