Green’s Dictionary of Slang

a native of Leicestershire; thus bean-bellied adj.

1606		Wily Beguiled 13: I scorne that base, broking, brabbling, brauling, bastardly, bottlenos’d, beetle-brow’d bean-bellied name.
1622		M. Drayton Polyolbion III (1876) xxiii 95: Bean belly, Lestershire her attribute doth bear.
1662		Fuller Worthies (1840) II 225: ‘Bean-belly Leicestershire’ [...] Those in the neighbouring counties use to say merrily, ‘Shake a Leicestershire yeoman by the collar, and you shall hear beans rattle in his belly’.
1878		Luton Times 12 July 7/5: Beanbelly , Leicestershire [...] ‘Shake a Leicester yeoman by the collar, and you’ll hear the beans rattle in his belly’.
1887		N.Y. Tribune 28 Apr. 6/1: ‘Bean-belly’ is a choice bit of slang [...] It is a nickname for an inhabitant of Leicestershire, where the bean habit is stroingly developed.