Poor as (or meaner than) gar broth.

The 1800s American frontier metaphor, “Meaner than gar broth,” referred to gar fish broth which was a common, almost inedible poor man’s soup made of alligator gar which, though plentiful in the frontier rivers, was not a fish of choice for eating and therefore of no economic value. Synonyms for “meaner” include, shabbier, sparser, and poorer. And so, “Poor as gar broth” refers to someone so poor he or she must resort to eating the same.