OK for the sake of an answer:
When small, flake, daphnia, blood worm etc.
When larger, small pellets, brine shrimp.
When over the 8" mark - all of the above plus neon tetras etc.
When over the 15" mark larger fish, worms, mussel etc.
Keep going till abou 48" and from this point they turn veggie and start consuming fallen fruit, nuts etc.
Now quit it.