Hunger matters around mealtime, starter polished off before one (3,8)
I believe the answer is:
the munchies
'hunger' is the definition.
'matters around mealtime starter polished off before one' is the wordplay.
'matters' becomes 'themes'.
'around' indicates putting letters inside.
'mealtime' becomes 'lunch'.
'starter polished off' means to remove the first letter.
'before one' becomes 'i' (Roman numeral. I am not sure about the 'before' bit.**).
'lunch' with its initial letter taken away is 'unch'.
'unch'+'i'='unchi'
'themes' placed around 'unchi' is 'THE MUNCHIES'.
(Other definitions for the munchies that I've seen before include "Sudden strong desire for food" , "what affects avid consumer" .)