I often drop a little bit of Bear Pipe (counts as Vegetable, I think) into soup or stew, and it feels like the entire soup becomes as invigorating as a beverage from this. That suggests the invigoration was implemented as an either/or factor, not a fluid thing depending on substance concentration.
Might be a little less realistic, but I came to enjoy it. Gives you the "you won't believe my soup recipe, it kicks, bro" feeling.