Objectives: Breastfeeding in the first years of life seems to be an important factor that affects shaping the body mass, and body mass/height proportion during first months of life as well as breastfeeding importantly differentiates body mass and body proportion at the later stages of the human ontogenesis. The aim of this study was to evaluate if duration of breastfeeding affects BMI in later life.
Material: In the analysis 470 children born in time, aged 8-49 months were included. The data came from the nurseries in Lodz (central Poland) where children's parents filled the questionnaires and were collected in years 1993-1997. In the analysis was included information about: duration of breastfeeding, parental educational level, birth body weight, birth body length. The BMI was standardized on sex and age of the children. The stepwise regression models were used to evaluate the hypothesis. The obtained residues for BMI were used to verify only breastfeeding impact using the regression analysis.
Results: The regression model included parental education level and birth parameters were used to adjust BMI on them and revealed that low educated mothers had children with higher BMI (Beta=0.213; p<0.015). Additionally, heavier newborns had higher BMI at the later stages of ontogenesis (Beta=0.207; p<0.001). There were made two regression analyses using BMI residues. The first one treated breastfeeding as categories, and revealed that children breastfed over 6 months vs. not breastfed or breastfed no longer than 1 month had lower BMI (Beta=-0.098; p<0.030). The second model treated duration of breastfeeding as a continuous variable, and showed that breastfeeding duration was inversely correlated with BMI residues (Beta=-0.092; p=0.042).
Conclusions: Duration of breastfeeding differentiates the BMI among Polish children aged 8-49 months and seems to reduce BMI in further life.
Trial registration: This study was conducted according to the guidelines laid down in the Declaration of Helsinki and all procedures involving research study participants were approved retrospectively by the Ethical Commission at the University of Lodz (NR21/KBBN- UŁ/I/2018). Written informed consent was obtained from all subjects' parents.