Table 1 Background information on subjects in each group.

	Group I	Group II	Group III
Number (male/female)	36 (20/16)	77 (37/40)	54 (32/22)
Gestational age range (weeks)	29–32	33–36	37–41
Birth weight (g)*	1583 (36)	2133 (35)	3056 (66)
Birth weight range (g)	1322–2318	1426–2992	2300–4400
Milk intake	Breast milk	Breast milk	Breast milk
Day 3 (ml/kg/day)*	48.5 (5.2)	65.5 (8.1)	81.5 (7.7)
Day 7 (ml/kg/day)*	91.0 (5.1)	112.2 (8.8)	137.4 (11.1)

*Values are mean (SE).