Small idea

You could add a hunger system. If you don't eat you could die. This is just an idea to make the game a bit more realistic.

Add another bar that would drop like a rock?

I guess it could work.

Seems like it would be nothing but a burden. I can see no good coming from this other than to give us another constantly reappearing threat. If you lose all your money that means you gotta get some more really fast or you die of starvation.

Hm. Then people would mug. (Possibly.) >.>

I’ve seen this integrated in other role playing games with supposed intent of realism.
Though most would be able to surmise it themselves after a smidge of retrospect I’ll spell it out; it does not work well. That is of course, presuming the function is meant as more then a parasitic drain on various resources of the player, from money, to time, even opportunity. All too frequently have people run off in search of a burger or some manner of fantasy realm fried chicken in the midst of an imperative moment of role play. Interstices such as these are comical at best; the most we’d likely see here would be L ordering his Task Force to go on a fast food retrieval mission. They seem to know when to happen as well, as if puppeteered by some malevolent deity.
I personally don’t require any more counters reminding me of my eagerly approaching demise at my age either.
In short, for shortsighted, it’s a nice idea in theory, but think it any further then that and its junk, more often then not.