Favourite leader's lost weight where some US VIPs have gained stones (9)
I believe the answer is:
arlington
'where some us vips have gained stones' is the definition.
(US military cemetery)
'favourite leader's lost weight' is the wordplay.
I cannot really understand how this works, but
'weight' could be 'ton' (ton is a kind of weight) and 'ton' is located in the answer.
The remaining letters 'arling' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
(Other definitions for arlington that I've seen before include "American cemetery" , "US National Cemetery site" , "in Texas" , "American county" , "Casualties lying here" .)