Skip to main content

Table 2 Macronutrient and energy content in preterm and term human milk (n = 45) during the daytime

From: Circadian changes in the composition of human milk macronutrients depending on pregnancy duration: a cross-sectional study

 Time of day (hours)
6 AM – 12 PM6 AM – 6 PM6 AM – 12 AM12 PM – 6 PM12 PM – 12 AM6 PM – 12 AM
Protein, g/100 mL\( \overline{x}\pm s \)1.37 ± 0.2
1.43 ± 0.2
1.37 ± 0.2
1.41 ± 0.2
1.37 ± 0.2
1.37 ± 0.2
1.43 ± 0.2
1.41 ± 0.2
1.43 ± 0.2
1.37 ± 0.2
1.41 ± 0.2
1.37 ± 0.2
p value< 0.001**0.02*0.900.240.001*0.02*
Cohen’s d0.30a0.20a00.100.30a0.20a
Fat, g/100 mL\( \overline{x}\pm s \)4.06 ± 0.9
4.39 ± 1.1
4.06 ± 0.9
4.57 ± 1
4.06 ± 0.9
4.00 ± 0.7
4.39 ± 1.1
4.57 ± 1.0
4.39 ± 1.1
4.00 ± 0.7
4.57 ± 1.0
4.00 ± 0.7
p value0.04*0.001*0.650.280.02*< 0.001**
Cohen’s d0.33a0.50b0.070.170.42a0.66b
Carbohydrate, g/100 mL\( \overline{x}\pm s \)7.39 ± 0.2
7.33 ± 0.3
7.39 ± 0.2
7.33 ± 0.2
7.39 ± 0.2
7.37 ± 0.2
7.33 ± 0.3
7.33 ± 0.2
7.33 ± 0.3
7.37 ± 0.2
7.33 ± 0.2
7.37 ± 0.2
p value0.120.140.400.880.270.22
Cohen’s d0.24a0.24a0.0800.160.20a
Energy, kcal/ 100 mL\( \overline{x}\pm s \)74.42 ± 9.1
77.58 ± 10.0
74.42 ± 9.1
79.18 ± 9.7
74.42 ± 9.1
73.89 ± 6.8
77.58 ± 10.0
79.18 ± 9.7
77.58 ± 10.0
73.89 ± 6.8
79.18 ± 9.7
73.89 ± 6.8
p value0.03*< 0.001**0.590.290.01*< 0.001**
 Cohen’s d0.33a0.51b0.070.160.43a0.63b
  1. \( \overline{x} \) ± s mean value ± standard deviation; Cohen’s d – Cohen’s d effect size
  2. a – small effect size, b medium effect size; significant differences are highlighted in bold (*p < 0.05; **p < 0.001)