Me in new trade for protein-rich food (3,4)
I believe the answer is:
red meat
'protein-rich food' is the definition.
I can't judge whether this definition defines the answer.
'me in new trade' is the wordplay.
'in' is an insertion indicator.
'new' indicates an anagram.
'trade' anagrammed gives 'redat'.
'me' placed within 'redat' is 'RED MEAT'.
'for' is the link.
Can you help me to learn more?
(Other definitions for red meat that I've seen before include "Beef e.g." , "Lamb perhaps" , "iron-rich item" , "non-vegetarian food" , "Maybe beef" .)