I'm guessing this whole food argument has something to do with being able to spam long rest. If this is the case I think they should make it so there are only specific places you can long rest safely like an inn or an area obviously guarded. But if the player takes a long rest in a place like a forest or cave were there is bound to be danger; there should be random encounters, and you should have to pay a food price. "unlimited food" isn't the issue. The issue is long rest itself isn't balance. The fact I can long rest in a cave with giant hostile spiders without consequences is a problem. Also food shouldn't have healing properties in battle or otherwise.
You are looking at Long Rest as if the party rests right there in the cave of spiders. The concept is that the party leaves, finds their camp, and then long rests in a nice, safe location. Thus, random encounters would not apply. Larian is simply cutting out all the travel with a sort of "fade to black" effect.
So many think the rest issue is easily solved, but I've learned that it is far more complicated than it seems. Hence, I have been trying to develop a system that might work, hoping Larian will take some ideas from it.
Food spoiling could be a good, realistic mechanic, but I'm now leaning towards the idea that food should give some sort of bonus as opposed to being a requirement for resting.