Im thinking it would be interesting to not only do the food and water aspect, but because of the "Sick" Debuff you can get from drinking the "Nasty Water" wouldnt it be interesting to also have other features? 

Imagine if you are sick from drinking the Nasty Water, you can get Diarrhea which could potentially lead to more water loss and hunger loss. You could get Dysentry etc. What if you are tracking that spider you want to kill, and you get sudden pains which gives you a Debuff because you got constipated. Just a few ideas I thought of.

Yes that would be a nice idea. That you can no longer jump with a full backpack and sprint would be nice too.