Tried to lose (6)
I believe the answer is:
dieted
'tried to lose' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dieted that I've seen before include "Tried to lose weight" , "Regulated one's food consumption" , "Followed an eating regime" , "Followed a food regime" , "Went on strict food regime" .)