The median ( interquartile range ) energy and protein supplies during the first 4 weeks of life were higher in the intervention group : 139 ( 128-145 ) versus 126 ( 121-128 ) kcal kg day ( P < 0.001 ) and 4.0 ( 3.9-4 .2 ) versus 3.2 ( 3.1-3 .3 ) g kg day ( P < 0.001 ) .