Soda pie turned out fatty (7)
I believe the answer is:
adipose
'fatty' is the definition.
('adipose' can be a synonym of 'fatty')
'soda pie turned out' is the wordplay.
'turned out' indicates anagramming the letters.
'soda'+'pie'='sodapie'
'sodapie' is an anagram of 'ADIPOSE'.
(Other definitions for adipose that I've seen before include "Is a dope fat?" , "Like a sort of fat" , "Relating to fat" , "Relating to fatty tissue" , "Composed of animal fat" .)