Gothic health depletion in Returning 2.0

I recently installed Gothic 2 Returning 2.0, and like it so far, but my health keeps depleting. I thought I was poisoned at first, so I drank an antidote, but this did nothing. It's getting to where it's difficult to keep up with the amount of healing I have to do. Anyone know what's going on here?

You're supposed to eat & drink - are you doing that?