Filling food ultimately ruins dessert (4)

I believe the answer is:

spud

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'filling food' is the definition.
'spud' can be an answer for 'food' (spud is a kind of food). I'm unsure of the 'filling' bit.

'ultimately ruins dessert' is the wordplay.
'ultimately' indicates one should take the final letters.
'dessert' becomes 'pud' (short for pudding).
The final letter of 'ruins' is 's'.
's'+'pud'='SPUD'

Can you help me to learn more?

(Other definitions for spud that I've seen before include "one's eyed" , "Weeding spade" , "Commoner's King Edward?" , "Spade; potato (slang)" , "Vegetable" .)

I've seen this clue in The Independent.

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