A party leader has little desire for food (8)
I believe the answer is:
appetite
'desire for food' is the definition.
(I've seen this in another clue)
'a party leader has little' is the wordplay.
'party leader' becomes 'p' (I've seen this in other clues).
'has' is a charade indicator (letters next to each other).
'little' becomes 'petite' (similar in meaning).
'a'+'p'+'petite'='APPETITE'
(Other definitions for appetite that I've seen before include "Natural desire to satisfy a need" , "thirst" , "Justification for dining" , "'Strong desire, craving (8)'" , "Hunger; desire" .)