Don't eat regularly from odd unhealthy portions (4,4)

I believe the answer is:

fast food

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'unhealthy portions' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'don't eat regularly from odd' is the wordplay.
'don't eat' becomes 'fast' (fasting is not eating).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'from'+'odd'='fromodd'
The alternate letters of 'fromodd' are 'food'.
'fast'+'food'='FAST FOOD'

Can you help me to learn more?

(Other definitions for fast food that I've seen before include "Fish and chips, burgers, etc" , "Burgers or kebabs (but not snails!)" .)

I've seen this clue in The Independent.

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