The Association Between Breastfeeding and Body Composition During Adolescence (P11-123-19)

Abstract

ObjectivesTo investigate whether breastfeeding duration during infancy was related to body composition in adolescence. MethodsThe analytic sample comprised 536 Mexico City adolescents enrolled in an ongoing cohort study. Breastfeeding duration was estimated based on mother’s report of when she started and stopped breastfeeding, assessed during follow up visits at 1, 3, 6, and 12 months postpartum. Trained health professionals conducted the anthropometric assessment of weight, height, waist circumference, and triceps, suprailiac, and subscapular skinfold thicknesses. Bioelectrical impedance was used to derive the fat, muscle, lean and trunk fat masses and percentages. Sex-specific linear regression was performed with body composition measures as outcomes and breastfeeding duration in months as a continuous exposure, accounting for age, maternal education, maternal smoking during pregnancy, maternal parity, birth weight, and length, length of gestation, and adolescent maturation status. ResultsThe median (IQR) age was 14.62 (3.90) years, and 51.49% were females. Mean (SD) Body Mass Index Z-score was 0.58 (1.19) for females and 0.42 (1.29) for males. Breastfeeding duration ranged from 0 to 34 months with a median duration of 6.50 (9.00) and 7.00 (8.00) months in females and males, respectively. In males, there was a statistically significant positive association between duration of breastfeeding and skeletal muscle and lean mass in crude models (β = 0.19 [95% CI 0.07, 0.30] and β = 0.29 [95% CI 0.11, 0.46], respectively. Nonetheless, these associations were attenuated and no longer statistically significant when age and other covariates were included in the linear model (for muscle mass β = 0.02 [95% CI - 0.06, 0.10]) and lean mass β = 0.03 [95% CI - 0.09, 0.15]). There were no associations between breastfeeding duration and other body composition outcomes either in crude or adjusted sex-specific models. ConclusionsAfter accounting for potential confounders, there was no evidence of a relationship between breastfeeding duration and adolescent body composition. Age was a crucial confounder, as younger adolescents in the cohort had shorter breastfeeding duration and lower skeletal and lean mass. Funding SourcesNIH/NIEHS and EPA.