The most common and most likely answer to this crossword clue is the 4 letter word ITAL
I
T
A
L
Buddy explains!

The straight part
We know that "Natural Rastafarian food" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case natural rastafarian food = ital.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 ITAL mean?
ITAL noun- (Iyaric) Pure, natural food suiting a Rastafari lifestyle.
- (of a typeface or font) Designed to resemble a handwriting style developed in Italy in the 16th century.
- (of a typeface or font) Having letters that slant or lean to the right; oblique.