Impact of infant feeding status on maternal body composition

Abstract

Background: Overweight and obesity are related to a greater risk for health problems throughout life. Maternal overweight and obesity is related to complications during pregnancy that endanger the health of the mother and her developing fetus. Pregnancy is also a time when excessive weight can be gained leading the mother susceptible to an increased risk of long term overweight or obesity and entering subsequent pregnancies with a higher BMI. Breastfeeding has been shown to create a caloric deficit to promote weight loss, yet no study has assessed breastfeeding exclusivity at 3 months and maternal body composition at 6 months as well as breastfeeding exclusivity at 6 months and maternal body composition at 6 months. Purpose: The purpose of this study was to explore the relationship between infant feeding status at three and six months post-partum and maternal body composition at six months post-partum. Methods: Twenty-five mothers were included in this analysis. Mothers were included if they met the criteria of a BMI 18.5 – 40 kg/m2, of a singleton pregnancy, healthy, completed a 3 month post-partum follow-up visit with breastfeeding questionnaire and a 6 month post-partum follow-up visit with breastfeeding questionnaire and Bod Pod test. Mothers were dichotomized into exclusive breastfeeding and non-exclusive breastfeeding. Maternal body composition was measured by air displacement plethysmography by the Bod Pod. ANOVA assessed the relationship between maternal breastfeeding status at 3 months and maternal body composition at 6 months as well as the relationship between maternal breastfeeding status at 6 months and maternal body composition at 6 months. Multiple linear regression assessed the relationship between post-partum weight loss 0-3 months and 3-6 months and maternal body composition at 6 months. Significance was determined at a level of p < 0.05. Results: The mean age of the participants was 30.4 years, the mean pre-pregnancy BMI was 26.6 kg/m2, and the mean total PPWL was 11.6 kg ± 5.5 kg. Differences were found between groups for the amount of total PPWL (exclusive: 13.2 ± 5.3 kg and non-exclusive: 8.4 kg ± 4.7 kg; p=0.017) and PPWL 3 to 6 months (exclusive: 2.6 ± 1.7 kg and non-exclusive: 0.06 ± 3.2 kg; p=0.039). When examining breastfeeding status at 3 months, no between group (exclusive vs. non-exclusive) differences were found for maternal body composition. Similarly, when examining differences in breastfeeding status at 6 months, no differences in maternal body composition was found. Linear regression showed post-partum weight loss from 3 to 6 months predicted maternal %fat (β = 1.87, R2=0.22; p = 0.010), FM (β = 0.608, R2=0.34; p = 0.001) and FFM (β = 0.473, R2=0.19; p = 0.017). Conclusion: No relationship was found between breastfeeding exclusivity assessed at 3 and 6 months post-partum and maternal body composition at 6 months post-partum. However, a relationship was found among PPWL 3 – 6 months post-partum and maternal %fat, FM, FFM at 6 months post-partum. Future research is needed to better support these relationships as well as to determine to mechanisms which influence them.