[guineapig]

Food durations and stats have been covered many times on the forums.

My guess would be that durations were one of the many things that they intended on messing around with then they launched EQ but never got around to it till later on. This is no different than the fact that there were many recipes in classic that you could find throughout the world that did not actually get added to the game till Kunark.

Again, this is just my guess, but until I see proof otherwise, all food had the same duration UNTIL the changes to food duration were implemented. It really makes no less sense than any other silly classic things (like clerics with + intelligence gear).