Heavy food awkward to digest without it (6)
I believe the answer is:
stodge
'heavy food' is the definition.
(I've seen this before)
'awkward to digest without it' is the wordplay.
'awkward' indicates anagramming the letters.
'without' indicates named letters should be taken away.
'to'+'digest'='todigest'
'todigest' with 'it' taken away is 'odgest'.
'odgest' with letters rearranged gives 'STODGE'.
(Other definitions for stodge that I've seen before include "Heavy, uninteresting food" , "Heavy pud" , "'Heavy, starchy food (6)'" , "Dull work" , "Heavy filling food" .)