Cream tea, extremely deficient and low in calories (5)
I believe the answer is:
elite
'cream' is the definition.
(I've seen this before)
'tea extremely deficient and low in calories' is the wordplay.
'extremely deficient' means to look at the middle letters.
'and' is a charade indicator (letters next to each other).
'low in calories' becomes 'lite' (I've seen this before).
The middle of 'tea' is 'e'.
'e'+'lite'='ELITE'
(Other definitions for elite that I've seen before include "Cream, the pick" , "Select body, cream" , "Selected as the best" , "Aristocratic" , "top drawer?" .)