Food, you must swallow good? Right (6)
I believe the answer is:
yogurt
'food' is the definition.
(I know that yogurt is a type of food)
'you must swallow good? right' is the wordplay.
'must swallow' is an insertion indicator.
'good?' becomes 'g' (abbreviation).
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'you' enclosing 'g' is 'yogu'.
'yogu'+'rt'='YOGURT'
(Other definitions for yogurt that I've seen before include "Cultured fare" , "Cultural fare" , "Thick dairy product" , "Semi-liquid dairy product" , "Grouty (anag.)" .)