Heading off, one subsidising fellow journalist short of fare (8)
I believe the answer is:
underfed
'short of fare' is the definition.
(fare means food)
'heading off one subsidising fellow journalist' is the wordplay.
'heading off' means to remove the first letter.
'one subsidising' becomes 'funder' (someone subsidising or funding something).
'fellow' becomes 'f' (abbreviation - of a society etc.).
'journalist' becomes 'ed' (short for editor).
'funder' with its first letter taken off is 'under'.
'under'+'f'+'ed'='UNDERFED'
(Other definitions for underfed that I've seen before include "in a starved condition" , "Malnourished" , "deprived of basic need" , "Not having enough to eat" , "Too thin?" .)