Food and drink, very filling, source of nutrition in stomach (9)

'food and drink' is the definition.
I know nothing about this answer so I can't tell whether this works.

'very filling source of nutrition in stomach' is the wordplay.
'very filling' becomes 'inger' (I can't justify this - if you can you should give a lot more credence to this answer).
'source of' says to take the initial letters (the start - or source - of the word).
'in' is an insertion indicator.
'stomach' becomes 'gut' (I've seen this before).
The initial letter of 'nutrition' is 'n'.
'inger'+'n'='ingern'
'ingern' placed within 'gut' is 'GINGERNUT'.

Can you help me to learn more?