Food conference (4)
I believe the answer is:
diet
I believe this is a double definition.
'food' is the first definition.
(diet is a kind of food)
'conference' is the second definition.
(thesaurus)
(Other definitions for diet that I've seen before include "Prescribed selection of foods" , "Restricted cheer" , "Slimmer's regimen" , "cut down" , "International conference" .)