Starchy bread modified to contain zero sugars etc (13)

I believe the answer is:

carbohydrates

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'sugars etc' is the definition.
I can't tell whether this defines the answer.

'starchy bread modified to contain zero' is the wordplay.
'modified' is an anagram indicator.
'to contain' means one lot of letters goes inside another.
'zero' becomes 'O' (O resembles 0).
'starchy'+'bread'='starchybread'
'starchybread' is an anagram of 'carbhydrates'.
'carbhydrates' placed around 'o' is 'CARBOHYDRATES'.

Can you help me to learn more?

(Another definition for carbohydrates that I've seen is " Source of energy in food".)

I've seen this clue in The Times.

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