1	exp protein intake/
2	((protein or hydrolysate or hydrolys* or hydrolyz*) not formula$).ti,ab.
3	1 or 2
4	exp breast milk/
5	((human or breast or expressed) adj2 milk$).ti,ab.
6	((mother$ or maternal or donor$) adj2 milk$).ti,ab.
7	4 or 5 or 6
8	(infan* or newborn or neonat* or premature or very low birth weight or low birth weight or VLBW or LBW).mp.
9	exp infant/
10	8 or 9
11	(human not animal).mp.
12	(randomized controlled trial or controlled clinical trial or randomized or placebo or clinical trials as topic or randomly or trial or clinical trial).mp.
13	10 and 11 and 12
14	3 and 7 and 13