A prescribed selection of foods (4)
I believe the answer is:
diet
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a prescribed selection of foods</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for diet that I've seen before include "Prescribed food - council" , "regular intake" , "Legislative assembly in some countries" , "Restrict food-intake" , "(Perhaps, try to) reduce rump; parliament" .)