Changes new diets (5)
I believe the answer is:
edits
'changes' is the definition.
(editing is a kind of changing)
'new diets' is the wordplay.
'new' indicates an anagram.
'diets' anagrammed gives 'EDITS'.
(Other definitions for edits that I've seen before include "Redacts" , "Corrects" , "Tides (anag.)" , "Puts together" , "Directs newspaper production" .)