There is not a limited supply of food in the game. There are vendors that have an unlimited supply of cheap food. And you can always wander around outside looking for stuff to fight to earn a little extra cash (which I do, also for the xp). Besides, A6 required food, and I never had an issue there. I ran all over the place (didn't always use the pylons), and I was fine on food. As for using it to heal, that didn't really seem needed. If I got hurt and needed to heal but didn't want to spend mana, I'd step outside, walk back and forth a few times and I was full health again.
Now don't get me wrong, I still love the game, but it does feel as if it's being overly simplified. I remember in the first game you needed a light source in dark dungeons. You used to need food when resting. But to make things simpler, they got rid of that.