I think it would be much easier to just reduce the amount of food we can find drastically with almost the same effect. If you don't have a lot of food in the first place, you will also think twice about resting. No offense, but I think the approach you are suggesting is just too complicated for a videogame where the developers are already struggling to not overwhelm new players who don't know DnD 5e with all the rules and mechanics.
Also I am not a fan of saying goodbye to NPCs that have a rich story of their own just because 'they cost me food'. I mean sure, I almost never actually use Gale for example, but I like having him around in my camp anyway because I like my camp to feel alive and I like interacting with him and finding out about his story, even if I don't run around with him all the time.
