From clinical facts, fat stores (adipocytes) serve as a
reservoir for formation of extra sex hormones, the more you have,
the higher your storage are and the production rate will be when
the need comes.
These hormones are better known as gonadocorticosteroids and is
primarily produced by the adrenal glands, secondly produced by the
fat cells.
Though it may seem that prosperous gals may have higher
'horniness', but I still think it varies across the prosperous
individuals...