German weight-watcher? (6)
I believe the answer is:
dieter
I believe this clue is a double definition.
'german' is the first definition.
(common German name)
'weight-watcher?' is the second definition.
(I've seen this in another clue)
(Other definitions for dieter that I've seen before include "One who's slimming" , "The weight-watcher" , "One watching one's weight" , "German boy" , "German fellow" .)