From the 1971 song "Amos Moses", a phrase referring to a person that gorges on
food. It
literally means that one can eat the equivalent of their weight in
food, and unless the person exercises vigorously, the chances are high that they're huge.
(There) lived a man named Doc Milsap and his
pretty wife Hanna, (and) they raised up a son who could eat up his weight in groceries! Named him after a man of the cloth, Called him Amos Moses!" -Jerry Reed, "Amos Moses