What are the mean milk production rates of American women?
0.78L/day in term infants from birth through 6 months
0.6L/day in term infants from 7-12 months of age
How is the EER for lactation calculated?
EER=Adult/adolescent EER (depending on age)+milk energy output-weight loss
Does the protein content in human milk change with the mothers diet?
No. The concentration of protein in human milk is not influenced by diet or body composition even in undernourished mothers
How much protein is required to maintain good milk production in healthy mothers?
Protein intakes of 1g/kg body weight/day are needed to promote the conservation of skeletal muscle in order to maintain good milk production in lactating mothers
How is protein intake for lactating women determined?
Factorial approach is utilized
It is assumed that the process of lactation does not alter the maintenance protein requirement
Protein and/or amino acid requirement is increased in proportion to milk production
Describe the levels of non-protein nitrogenous substances in human milk.
Human milk is characterized by a relatively high concentration of non-protein nitrogenous substances.
Non-protein nitrogenous substances contribute approximately 20-27% of total milk nitrogen
What is the quantitatively important non-protein nitrogen component in milk?
Where do mothers get their increased nitrogen needs?
It is assumed that part of the increased nitrogen needs of the lactating woman to produce milk non-protein nitrogen will come from dietary protein
How was the protein EAR for lactating women calculated?
The average protein equivalent of human milk nitrogen output during the first 6 months of lactation was divided by the average incremental efficiency of dietary protein utilization
The values for the various moths of lactation were then averaged to set the amount by which the EAR for non-lactating women should be increased by as +21g/day
What is the protein EAR for lactating women?
1.05g/kg/day or +21g/day additional protein
What is the protein EAR for non-lactating women?
What is the protein EAR for lactating women?
What is the protein RDA for non-lactating women?
What is the protein RDA for lactating women?
How is the protein RDA for lactating women calculated?
Requirement for protein losses during lactation = 21.2
21.3x1.24=26.3 (rounded to 25)
26.3/57(average weight)=0.46 (increase factor)
What is the AI for lineoleic acid for lactating women?
13g/day for all age groups
What type of fatty acid is linoleic acid?
Why does lineoleic acid have an AI and how is it determined?
Due to lack of evidence for determining the requirement during lactation, the AI is set based on the median lineoleic acid intake of lactating women where a deficiency is basically nonexistant in free-living populations
How are n-3 FA secreted in milk during lactation?
The demand for secretion of n-3 polyunsaturated fatty acids in milk during lactation must be met by n-3 fatty acids from maternal tissues or through dietary intake
How are plasma and RBC lipid DHA levels affected during lactation?
Lower plasma and red blood cell lipid DHA levels are present in lactating women compared to non-pregnant, non-lactating women
How can DNA levels be increased in both the mother and newborn infant?
Supplementation with fish oil
Why do lactating women experience lower plasma and red blood cell lipid DHA levels?
May reflect declining DNA status due to inadequate n-3 FA intakes in the women in these studies
Changes in maternal DNA levels are normal physiological responses to the changes in endocrine status, lipoprotein and lipid metabolism, or nutrient transfer that accompany pregnancy and lactation
What is the AI for alpha-linolenic acid during lactation and how is it determined?
Because of a lack of evidence for determining the requirement during lactation, the AI is set based on the median alpha-linolenic acid intake of lactating women where a deficiency is basically non-existent in free-living populations
How can an n-3 deficiency be combated?
Small amounts of EPA and DHA can contribute towards reversing an n-3 fatty acid deficiency and can therefore contribute towards the AI for alpha-linolenic acid
How does the requirement for CHO change during lactation?
The requirement for CHO increases during lactation
Why are CHO requirements increased during pregnancy?
Higher respiratory quotient and rates of CHO utilization have been reported in lactating women compared with non-lactating women
Consistent with the preferential use of glucose by the mammary gland
What is the lactose content of human milk?
How is lactose synthesized?
Lactose is synthesized from glucose and so an increased supply of glucose must be obtained from ingested carbohydrates
Or via an increased supply of amino acids in order to prevent utilization of the lactating woman's endogenous proteins for glucose production
How do maternal fat stores contribute to lactose formation?
Glycerol derived from endogenous or exogenous fat may contribute to the increased production of glucose through gluconeogenesis. However, the amount of fat that can be oxidized daily greatly limits the contribution of glycerol to glucose production and thus lactose fermentation
What is the carbohydrate EAR for lactation?
What is the carbohydrate RDA for lactation?
How is the carbohydrate EAR during lactation set?
Sum of the CHO intake necessary to replace the CHO secreted in human milk (60g/day) and the EAR for adolescent girls and women (100g/day)
How is the carbohydrate RDA during lactation set?
Set by using a CV of 15% based on the variation in brain glucose utilization
What is the AI for fiber during lactation?
Why is the AI for fiber the same for lactating and non-lactating women?
There is no evidence to suggest that the beneficial effects of fiber in reducing the risk fo CHD in adolescent girls and women is different from non-pregnant adolescent girls and women
Why are thiamin EAR levels increased during lactation?
For lactating women it is assumed that 0.16 mg of thiamin is transferred in their milk each day when daily milk production is 0.78L
An additional 0.1mg of thiamin is added to the EAR (0.9mg/day) for the nonpregnant, nonlactating women to cover the energy cost of milk production
What is the EAR for thiamin change during lactation?