Get infant out - not healthy (9)

I believe the answer is:

fattening

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'not healthy' is the definition.
I can't judge whether this definition defines the answer.

'get infant out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'get'+'infant'='getinfant'
'getinfant' with letters rearranged gives 'FATTENING'.

Can you help me to learn more?

(Another definition for fattening that I've seen is " of high-calorie food?".)

I've seen this clue in The Daily Express.

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