NOTE: Energy content is expressed in kcal per liter breast milk. The equations of Wang et al (previous section) are expressed in kcal per dL breast milk.
Parameters:
(1) lactose concentration in g/L
(2) total protein concentration in g/L
(3) fat concentration in g/L
(4) creamatocrit in percent
total energy content in kcal per liter breast milk =
= (3.95 * (lactose content)) + (4.0 * (protein content)) + (9.0 * (fat content))
creamatocrit = percent of length of fat in milk spun in a microcentrifuge tube =
= (length of cream layer in mm) / (total length of fluid in mm) * 100%
fat content in g/L =
= ((creamatocrit in percent) - 0.59) / 0.146 =
= (6.849 * (creamatocrit in percent)) - 4.04
total energy content in kcal per liter breast milk =
= (66.8 * (creamtocrit in percent)) + 290
total energy intake in kcal =
= (total energy content in kcal per liter) * (liter of breast milk ingested)
where:
• The paper has the equation as (290 + 66.8) * (creamatocrit) which makes little sense, especially when compared to results displayed in Figure 3 (page 1019).
• 1,000 kcal is equivalent to 4.2 MJ.
• The total energy content is dependent on lactose and protein in addition to the fat. The total energy is proportional to the creamatocrit but is greater than the amount of energy due to fat content predicted by the creamatocrit. For example, a creamatocrit of 6% corresponds to a fat content of 37 g/L which has a energy content of 333 kcal per liter while the total energy predicted is 690 kcal per liter.
