The Italian is after fast food (6)
I believe the answer is:
lentil
'food' is the definition.
(lentil is a kind of food)
'the italian is after fast' is the wordplay.
'the italian' becomes 'il' (the in Italian).
'is after' is a charade indicator (letters next to each other).
'fast' becomes 'lent' (I've seen this before).
'il' put after 'lent' is 'LENTIL'.
(Other definitions for lentil that I've seen before include "A legume, its seed" , "Edible leguminous plant seed" , "bit of food" , "High-protein pulse" , "Lintel (anag.)" .)