TABLE 1.

Human milk (mature) composition and formula comparison of commonly used formulas in the United States¹

	Energy, kcal/dL	Protein, g/dL	Protein, g/100 kcal
Mature human milk (7)1
Weeks 3–4 of lactation	66 (48–85)2	1.2 (0.8–1.6)	1.82
Weeks 10–12 of lactation	68 (50–86)	0.9 (0.6–1.2)	1.32
Routine 20-kcal/oz formula (8)	67.6	1.4	2.1
Routine 20-kcal/oz formula (9)	67.6	1.5	2.2
Routine 19-kcal/oz formula (10)	64.3	1.3	2.0

¹Transitional milk (week 2 of lactation) is reported to have 1.3 g of protein/dL. A range of values for mature milk from 0.9 to 2.1 g of protein/dL was reported in studies included in this review (33–38).

²Mean ± 2 SD, meta-analysis of 2299 mothers.