The most common and most likely answer to this crossword clue is the 9 letter word RATIONING
I've seen this crossword clue in Financial Times
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More clues leading to the result RATIONING
Buddy explains!
The straight part
We know that "restriction on what we eat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case restriction on what we eat = rationing.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does RATIONING mean?
RATIONING verb- To supply with a ration; to limit (someone) to a specific allowance of something.
- To portion out (especially during a shortage of supply); to limit access to.
- To restrict (an activity etc.)
- A ration.
- Controlled distribution of scarce resources such as food or fuel; used typically in wartime.