It's worth considering if OneBar should estimate health before something is done (e.g. eating, drinking a potion).

Specifically:

• Only for good (healing) or for bad (hurting) as well? How to indicate it?
• Is it easy to do with potions? Even non-standard ones? Poisonous food, suspicious soup?
• Consider hunger and poison effects
• Is there a concept of "waste"? How to indicate that?
• Should it consider existing potion effects? How?