Honestly, this discussion surprises me somewhat because of the dozens and dozens of videogames RPGs I have played, food has only rarely ever been a healing item, with potions and healing magic being far more prevalent.
That said, I can understand why they might think that. If they both didn't understand how healing occurred (didn't understand healing surges and rests yet) and saw an item in an inventory that did not have a clear use (food), it is perfectly reasonable for them to conclude that the item with no use will solve their problem with no answer.
I think the real videogame trope involved in their thought processes is the fact that it is very rare for videogame characters to carry food around with them. It is usually abstracted. If it is not abstracted, then it almost always is linked to healing/stamina/recovery/whatever. In other words, if you have food in a videogame, then it is linked to game mechanics. The fact that 4E has food as a notable purchasable item and doesn't link it to any game mechanics is a pretty wild oddity, really. You are expected to buy rations, but it is nothing more than a fluff/nod-to-simulationism element. Having it appear on a pregen character sheet is probably a mistake, since it can distract attention but serves no real purpose to the game itself (and certainly is needed there in order to learn the game).
Actually, now that I have written this all out, I am beginning to wonder why 4E didn't take a bit more of an effort to abstract out things like that... It would have fit the game's overall design philosophy.
