Pole with no excess fat? Not quite (4)
I believe the answer is:
spar
'pole' is the definition.
(spar is a kind of pole)
'with no excess fat? not quite' is the wordplay.
'with no excess fat?' becomes 'spare' (I've seen this before).
'not quite' means to remove the last letter.
'spare' with its last letter taken away is 'SPAR'.
(Other definitions for spar that I've seen before include "Box in training - nautical pole" , "microcrystalline mineral?" , "What boxers do" , "Mineral; strong pole" , "Practice boxing with wooden beam" .)