Enough dieting to make you fade away? (3)
I believe the answer is:
die
'fade away?' is the definition.
(I've seen this in another clue)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for die that I've seen before include "one's cast" , "Perish" , "Mould; become extinct" , "One spotted" , "Cease living" .)