Cheese used by well-fed Americans? (4)
I believe the answer is:
edam
'cheese' is the definition.
(I know that Edam is a type of cheese)
'used by well-fed americans?' is the wordplay.
'used by' indicates the answer is hidden within the clue.
'EDAM' is hidden within 'well fed americans'.
(Other definitions for edam that I've seen before include "Dutch market town famous for its cheese" , "Made into a nice cheese" , "edible sphere" , "something to have with crackers" , "Dutch food" .)