Fresh, cold and low in fat (5)
I believe the answer is:
clean
'fresh' is the definition.
(thesaurus)
'cold and low in fat' is the wordplay.
'cold' becomes 'c' (eg on taps).
'and' is a charade indicator (letters next to each other).
'low in fat' becomes 'lean'.
'c'+'lean'='CLEAN'
(Other definitions for clean that I've seen before include "Sterile" , "Pure; well-defined" , "Carrying no illegal drugs" , "Quite" , "thoroughly" .)