Lean body mass of well-nourished women is preserved during lactation

Abstract

To determine whether the lean body mass of well-nourished women was mobilized to support milk protein output during lactation, the body composition of 10 lactating and 10 nonlactating women was examined longitudinally at 6-wk intervals between 6 and 24 wk postpartum and at 52 wk postpartum, and that of 10 nulliparous women was examined at equivalent intervals, by using clinical anthropometry and whole-body potassium counting. Milk production was determined at 6-wk intervals during the period of exclusive breast-feeding (6-24 wk postpartum) by the test-weighing procedure. Milk composition was determined by chemical analysis. Dietary intakes were determined at 6-wk intervals between 6 and 24 wk postpartum from 3-d food records with use of a nutrient database. Lean body mass was maintained in women who exclusively breast-fed their infants during the first 6 mo postpartum while consuming dietary protein in amounts that exceeded those of their nonlactating counterparts by 55%. The high protein intakes were sustained throughout lactation despite a progressive reduction by 32% of milk protein output. Lean body mass was preserved throughout lactation in well-nourished women, suggesting that the metabolic needs of milk protein production were met solely by higher protein intakes of the lactating women.

Repeated measurements of energy intake, energy expenditure and energy balance in lactating Bangladeshi mothers

“…Some studies have found a weight loss, corresponding to a fat mass reduction (Forsum et al, 1992;Motil et al, 1998;Butte et al, 1999), and others no change (van Raaij et al, 1990;Goldberg et al, 1991;Lovelady et al, 1995), because of increased energy intake to compensate for lactation. In the present study the women lost weight between 3.5 and 5.5 months postpartum, most of which was fat-free mass, but there was also a reduction in suprailiac skinfold thicknesses.…”

“…Recently, attention has focussed on lactating women and a number of studies have investigated their energy expenditure and body composition (Goldberg et al, 1991;Adair & Popkin, 1992;Forsum et al, 1992;Guillermo-Tuazon et al, 1992;Piers et al, 1995;Dewey, 1998;Butte et al, 1997Butte et al, ,1999Krebs et al, 1997;Motil et al, 1998;Spurr et al, 1998). However there have been few longitudinal studies beyond 6 months post-partum (cf Lawrence et al, 1986) and most of the subjects were well-nourished mothers (van Raaij et al, 1990;Adair & Popkin, 1992;Motil et al, 1998).…”

“…However there have been few longitudinal studies beyond 6 months post-partum (cf Lawrence et al, 1986) and most of the subjects were well-nourished mothers (van Raaij et al, 1990;Adair & Popkin, 1992;Motil et al, 1998).…”

Os benefícios da amamentação para a saúde da mulher

“…After 1 year, the skin folds of the three groups presented no significant difference. 44 It is important to highlight that it has been already demonstrated that the weight loss of lactating women who exclusively breastfeed, which might reach 500 g a week between the fourth and the 14th week, does not interfere with the infants growth. 45 …”

“…[23][24][25][26][27] Many studies have presented the relationship between breastfeeding and postnatal amenorrhea, and the occurrence of a consequent longer intergestational period. 10,[28][29][30][31][32][33][34][35][36][37][38][39][40][41] Other benefits for lactating women are the faster loss of weight gained during the pregnancy, [38][39][40][42][43][44][45] and the reduced postnatal uterine bleeding, which leads to less anemia 10 due to the faster uterus involution caused by the greater oxytocin release. 46 If compared to the advance of the knowledge about the role played by breastfeeding and the human milk in the infants health, the knowledge about the benefits of breastfeeding for women is scarce, and, therefore, this topic must be further investigated in the next decades.…”