Wonderful to maintain large rolls of flesh (4)
I believe the answer is:
flab
'rolls of flesh' is the definition.
'wonderful to maintain large' is the wordplay.
'wonderful' becomes 'fab' (slang abbreviation of fabulous).
'to maintain' is an insertion indicator.
'large' becomes 'l'.
'fab' going around 'l' is 'FLAB'.
(Other definitions for flab that I've seen before include "Informally, unsightly fat" , "Soft loose flesh" , "spare tyre?" , "Ugly, surplus flesh" , "Sign of overeating" .)