Different plates are required for this kind of diet (6)
I believe the answer is:
staple
'required for this kind of diet' is the definition.
Both the answer and definition are adjectives. Maybe there's an association between them I don't understand?
'different plates' is the wordplay.
'different' indicates an anagram.
'plates' with letters rearranged gives 'STAPLE'.
'are' is the link.
Can you help me to learn more?
(Other definitions for staple that I've seen before include "Chief - paper fastener" , "Short U-shaped paper fastener" , "Paper fastener - basic foodstuff" , "Important; paper fastener" , "U-shaped wire to fasten papers together" .)