Producer of 2 into diet changes, eating unknown quantity (9)
I believe the answer is:
donizetti
'producer' is the definition.
Both the definition and answer are singular nouns.
Perhaps you can see an association between them that I don't see?
'of 2 into diet changes eating unknown quantity' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is located in the answer.
'unknown' could be 'z' (algebra) and 'z' is found within the answer.
'quantity' could be 't' (T is an example) and 't' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for donizetti that I've seen before include "writer of noted works" , "Italian composer" .)