Grunting, chew nuts — awful! (3-9)

I believe the answer is:

gut-wrenching

I'm a little stuck... Click here to teach me more about this clue!

'awful' is the definition.
Both the definition and answer are adjectives.
Maybe you can see a link between them that I can't see?

'grunting chew nuts' is the wordplay.
'nuts' is an anagram indicator (nuts can mean crazy).
'grunting'+'chew'='gruntingchew'
'gruntingchew' with letters rearranged gives 'GUT-WRENCHING'.

Can you help me to learn more?

(Another definition for gut-wrenching that I've seen is " Extremely upsetting".)

I've seen this clue in The Times.

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