Sports official eating whopper for charity (6)
I believe the answer is:
relief
'charity' is the definition.
(thesaurus)
'sports official eating whopper' is the wordplay.
'sports official' becomes 'ref'.
'eating' is an insertion indicator.
'whopper' becomes 'lie' (I've seen this before).
'ref' enclosing 'lie' is 'RELIEF'.
'for' acts as a link.
(Other definitions for relief that I've seen before include "new person on duty" , "help for needy countries" , "Rest - cure" , "Easement from pain or distress" , "Removal of stress" .)