Reared on baked food, say (4)
I believe the answer is:
bred
'reared' is the definition.
(I've seen this before)
'baked food say' is the wordplay.
'baked food' becomes 'bread' (I've seen this before).
'say' indicates a 'sounds like' (homophone) clue.
'bread' is a homophone of 'BRED'.
'on' is the link.
(Other definitions for bred that I've seen before include "Very (music)" , "Propagated, raised" , "Gave rise to" , "Multiplied" , "did produce issue" .)