In the UK I'd be suprised if like us most of the income of other poorer people didn't go to landlords/banks through rent/mortgage payment?
It may appear for those in state housing that food is their greatest outlay but that would only be if accommodation provided by welfare wasn't classed as "income".
In Twain's position, and time, would food have certainly been the greatest outlay?
http://www.hindustantimes.com/interactives/how-do-people-in-...