Food that has no nutrition at its core (6)
I believe the answer is:
bagels
'no nutrition at its core' is the definition.
I can't judge whether this defines the answer.
'food that' is the wordplay.
'food' becomes 'bagel' (bagel is a kind of food).
'that' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'bagel'+'s'='BAGELS'
'has' is the link.
Can you help me to learn more?
(Other definitions for bagels that I've seen before include "Doughnut-shaped bread rolls" , "Doughnut-shaped roll with hard crust" , "Ring-shaped bread rolls" , "Hard ring-shaped rolls" , "Jewish bread rolls" .)