Finest diet drug? (5)

I believe the answer is:
elite
'finest' is the definition.
(I've seen this in another clue)
'diet drug?' is the wordplay.
I cannot really see how this works, but
'diet' could be 'lite' (synonyms) and 'lite' is present in the answer.
'drug?' could be 'e' (E is another name for ecstasy) and 'e' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for elite that I've seen before include "Chosen ones" , "Choice group" , "top drawer?" , "Identified as the best" , "Upper crust" .)
