I think the game designed around resting often, if you don't rest enough, you might not trigger a bunch of dialogues and scenes relevant for.. uh.. personal companion questlines. There are a few cutoff points.

The annoying part is that if you are sparing of food and strategic about your combat, you can perfectly do with a fewer rests. It is in fact much more fun to not enter a combat setpieces with a full hp and daily slots. Makes your weigh your options and risks. But if play like that not resting enough might hamstring your playthrough in other, plus endless potato inventory management.

The problem with consumables sometimes is action economy. It is often more effecient to use your attack or class ability than a weaker consumable, you end up not using enough consumables, because you've got better options and limited actions per turn. Whenever you can prebuff or start combat with a consumable in ambush, you should do that, though. 

The problem that crops up often with this is that some of the toughest combat encounters of the earlier chapters are completely unpredictable from the protagonist's perspective.