Preterm infants ( birth weight 500-1249g ) were randomized to receive parenteral nutrition with MOSF ( 30 % Medium-chain triglycerides , 25 % Olive oil , 30 % Soybean oil , 15 % Fish oil ) or S ( S , 100 % Soybean oil ) both at two levels of fat intake : 2.5 or 3.5 gkg ( -1 ) d ( -1 ) , named 2.5 Fat and 3.5 Fat respectively .