The German artist’s consumer’s guide (9)
I believe the answer is:
dietitian
'consumer's guide' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'the german artist's' is the wordplay.
'the german' becomes 'die' ('the' in German).
'artist' becomes 'titian' (Titian is an example).
'die'+'titian'='DIETITIAN'
Can you help me to learn more?
(Other definitions for dietitian that I've seen before include "Initiated for food expert" , "Food specialist" , "Medical adviser" , "one who regulates courses" , "Food guru" .)