Forbid eating company food (5)
I believe the answer is:
bacon
'food' is the definition.
(bacon is a kind of food)
'forbid eating company' is the wordplay.
'forbid' becomes 'ban' (banning is a kind of forbiding).
'eating' indicates putting letters inside.
'company' becomes 'co' (abbreviation).
'ban' placed around 'co' is 'BACON'.
(Other definitions for bacon that I've seen before include "Cured back or side of pork" , "Francis -, twentieth century Ir. artist" , "Meat (brought home by a breadwinner?)" , "Thin slices of pig" , "See 9" .)