Macronutrient and energy contents of human milk fractions during the first six months of lactation

Abstract

Aim: To study the macronutrient and energy contents of human milk fractions during the first 6 mo of lactation. Study design: A total of 483 milk samples, including 52 pairs of fore‐ and hindmilk samples from 20 mothers, 253 samples from 53 donor mothers and 126 samples from 36 mothers of preterm infants, were collected longitudinally, starting at 1 wk postpartum and continuing monthly up to 6 mo. Protein, lactose and fat contents were measured and energy density estimated. Results: The protein content was significantly lower in fore‐ and hindmilk than in donor or preterm milk during the first months of lactation. In donor and preterm milk, the protein content declined consistently from 2.0 g/100 ml at 1 wk to half of that at 6 mo, and a similar trend was observed in fore‐ and hindmilk. Lactose content showed no significant changes between the groups or in the course of lactation. The fat content was highest in hindmilk, being approximately two‐ to threefold that of foremilk. Accordingly, hindmilk included 25–35 kcal/100 ml more energy on average than foremilk. Conclusions: The fat content of human milk increases in relation to breast emptying, while the other macronutritients of milk show only slight changes. When enteral feeding with high‐energy human milk is preferred, as in the case of very preterm infants, hind milk, with its higher fat content, would be a natural choice.

Preterm human milk composition: a systematic literature review

“…This is despite the reformulation of several human milk fortifiers since the latest enteral guidelines were released in 2010 (8) , suggesting that current nutrition regimens, including fortification practices, may still not be sufficiently optimised to meet the needs of extremely preterm infants. (33) Average 28·3 -Days 6-8, 13-15 N, lipid, lactose, E* Bauer & Gerss (6) 23-33 102 1-8 weeks Pro, lipid, carbohydrate, E Beijers et al (34) 25·7-36 45 1, 2 and 4 weeks N Beijers & Schaafsma (35) <36 65 Days 0-5, 6-14, 15-55 Lipid Chessex et al (36) Average 30·3 1 1 -N, lipid, carbohydrate, E* Corvaglia et al (13) 26-32 55 Day 10 N, lipid Ehrenkranz et al (37) 26-33 21 Days 2, 7, 14, 28, 42 Lipid Faerk et al (38) <32 (average 28) 101 1-10 weeks N, lipid, carbohydrate, E* Gross et al (20) 27-32 (43) 26-36 58 Days 1-28 N Maas et al (44) 25-29 79 1-11 weeks N, lipid, lactose, carbohydrate, E* Saarela et al (45) Average 31·4 36 1 week, 1, 2, 3, 4, 5, 6 months N, lipid, lactose, E* Sann et al (46) 26-35 41 < 6, 7-14, >15 d Pro, lipid, lactose Silber et al (47) Average 29·6 5 Days 9-17 N, lipid, lactose, E Stevens (48) 34-36 weeks 7 Days 3-25 N E, energy; *, calculated; Pro, protein. (34) †, Ehrenkranz (37) , Faerk (38) , Gross (20) *, Guerrini (39) , Jitta (40) , Lemons (16) †, Lucas (43) *, Saarela (45) , Sann (46) , Stevens (48) Kjeldahl (16,34) Kjeldahl without NPN correction (18,20,33,45,48) Micro Kjeldahl (17) Semi-micro Kjeldahl (21) Semi-micro Kjeldahl without NPN correction …”

“…Atwater specific factor system (20) Heats of combustion factors (18,33,40,44) Bomb calorimetry (16,17,42,47) 295·8 258·6-325.5 70·7 61·8-77·8 (34) †, Ehrenkranz (37) , Gross (20) *, Jitta (40) , Lemons (16) †, Lucas (43) *, Maas (44) †, Saarela (45) , Stevens (48) Kjeldahl (16,34) Kjeldahl without NPN correction (18,20,44,45,48) Semi-micro Kjeldahl (21) Semi-micro Kjeldahl without NPN correction (32,43) Lowry-Peterson (6) Esbach/Bogg (40) 1·37 0·88-2·10 Folch (37) Roese-Gottlieb (20,44,45) Colorimetry (16,18) Creamatocrit (6,40) 3·84 3·24-4·80 Lactose: Chromatography (16) Boehringer lactose assay kit (18,44) Unidentified (40) Unidentified (45) Unidentified (20) Total carbohydrate: Carbohydrate by difference (44) Colorimetry (6) 6·07 7·42…”

“…Atwater specific factor system (20) Atwater general factor system (45) Heats of combustion factors (18,40,44) Bomb calorimetry (6,16) 297·9 252·3-323·8 71·2 60·3-77·4 4 Bauer (6) *, Faerk (38) , Guerrini (39) , Lemons (41) †, Maas (44) † Kjeldahl (41) Kjeldahl without NPN correction (44) Lowry-Peterson (6) IR spectrophotometry (38) 1·33…”

“…1·71-2·60 Folch (37,46) Roese-Gottlieb (20,45) Colorimetry (16,18,33) De la Huerga (39) Van de Kamer (17) Creamatocrit (40) IR spectrophotometry (38) 2·80 1·60-3·90 Lactose: Chromatography (16,46) Boehringer lactose assay kit (18,33) Unidentified (40) Unidentified (45) Unidentified (20) Total carbohydrate: Beckman Glucose Analyzer (17) IR spectrophotometry (38) 6·01 6·73 5·04-7·12 6·20-7·10…”

“…Atwater specific factor system (20) Atwater general factor system (45) Heats of combustion factors (18,33,38,40) Bomb calorimetry (6,16,17) 267·8 205·0-309·6 64·0 49·0-74·0 (34) †, Corvaglia (13) , Ehrenkranz (37) , Gross (20) *, Guerrini (39) , Jitta (40) , Lemons (16) †, Lepage (42) †, Lucas (43) *, Maas (44) †, Sann (46) , Stevens (48) , Silber (47) † Kjeldahl (16,34,42) Kjeldahl with NPN not accounted for (13,18,20,33,44,47,48) Micro Kjeldahl (17) Semi-micro Kjeldahl (21) Semi-micro Kjeldahl without NPN (32,43) Biuret (46) Lowry-Peterson (6) IR spectrophotometry (13) Esbach/Bogg (40) 1·67…”