Starvation diet? (4,4)
I believe the answer is:
fast food
'starvation diet?' is the definition.
I know that 'diet' relates to this answer.
'starvation diet?' is the wordplay.
'starvation' becomes 'fast' (I can't justify this - if you can you should give a lot more credence to this answer).
'diet?' becomes 'food' (diet is a kind of food).
'fast'+'food'='FAST FOOD'
Can you help me to learn more?
(Other definitions for fast food that I've seen before include "Burgers or kebabs (but not snails!)" , "Fish and chips, burgers, etc" .)