This isn't a bug. Playing on one of the top two difficulty levels removes health regen from meditation. Forces you to use potions or food. I suppose it adds a certain level of forethought, though it doesn't really increase difficulty.

Or just buy food and eat :-)

no, i switch between the difficulty to restore it, but i dont understand the reason

Having a little fun with this thread ;)

I dont know, if I felt hungry or thirsty, and I decided to plop my butt down and meditate for an hour or a day, I'd still feel pretty damn hungry / thirsty.

My dislocated shoulder wouldn't reset. My wounds wouldn't stitch themselves.

Additionally, the game gives you full stacks of most food / drink items several times over. Stack = 100 items. There has to be some use for them.

The reason I guess would be there was a lack of time to implement a more fully fleshed out difference in difficulty levels? I don't know. I don't have an issue with it. There's an ability that increases standing regen. There's multiple concoctions that refill health in various ways. There's two potions that either give an instant refill of some health, and another that regenerates it over time. Then like I said, there's about a million food / drink items you can use constantly without ever worrying about getting fat and sluggish, clogged arteries, or diarrhea.