Breastfeeding reduces postpartum weight retention

Jennifer L Baker, Michael Gamborg, Berit L Heitmann, Lauren Lissner, Thorkild IA Sørensen and Kathleen M Rasmussen

American Journal of Clinical Nutrition, Vol. 88, No. 6, 1543-1551, December 2008


Background: Weight gained during pregnancy and not lost postpartum may contribute to obesity in women of childbearing age.

Objective: We aimed to determine whether breastfeeding reduces postpartum weight retention (PPWR) in a population among which full breastfeeding is common and breastfeeding duration is long.

Design: We selected women from the Danish National Birth Cohort who ever breastfed (>98%), and we conducted the interviews at 6 (n = 36 030) and 18 (n = 26 846) mo postpartum. We used regression analyses to investigate whether breastfeeding (scored to account for duration and intensity) reduced PPWR at 6 and 18 mo after adjustment for maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG).

Results: GWG was positively (P < 0.0001) associated with PPWR at both 6 and 18 mo postpartum. Breastfeeding was negatively associated with PPWR in all women but those in the heaviest category of prepregnancy BMI at 6 (P < 0.0001) and 18 (P < 0.05) mo postpartum. When modeled together with adjustment for possible confounding, these associations were marginally attenuated. We calculated that, if women exclusively breastfed for 6 mo as recommended, PPWR could be eliminated by that time in women with GWG values of ~12 kg, and that the possibility of major weight gain (≥5 kg) could be reduced in all but the heaviest women.

Conclusion: Breastfeeding was associated with lower PPWR in all categories of prepregnancy BMI. These results suggest that, when combined with GWG values of ~12 kg, breastfeeding as recommended could eliminate weight retention by 6 mo postpartum in many women.