Breastfeeding, Gestational Diabetes Mellitus, Size at Birth and Overweight/Obesity in Early Childhood

Background: Breastfeeding appears to reduce the risk of childhood overweight/obesity. However, it remains unclear whether this protective effect persists among high-risk populations. This study aims to investigate the association of breastfeeding with the risk of overweight/obesity in early childhood and whether this association is altered by gestational diabetes mellitus (GDM) or size at birth. Methods: Feeding practices during the first 12 months of age and weight and length at 12–36 months of age were collected. Full breastfeeding includes exclusive and predominant breastfeeding. Children with body mass index (BMI) values greater than 1 standard deviation from the mean of sex- and age-specific BMI were classified as overweight/obese. Multiple generalized estimating equations models were applied to analyze the associations of full breastfeeding duration with overweight/obesity risk. Results: Among all participants (n = 9329), infants with a longer full-breastfeeding duration had a reduced risk of overweight/obesity in early childhood compared with those breastfed for less than one month. Infants exposed to GDM and those born large for gestational age (LGA) had a higher risk of overweight/obesity in early childhood. Among infants of mothers with GDM (n = 1748), infants with full breastfeeding for greater than 6 months (aOR: 0.58; 95% CI: 0.44, 0.78) showed a decreased risk of overweight/obesity in early childhood compared with those breastfed for less than one month. Among LGA infants (n = 1279), infants with full breastfeeding for 3–5 months (aOR: 0.66; 95% CI: 0.57, 0.76) and greater than 6 months (aOR: 0.70; 95% CI: 0.56, 0.88) showed a decreased risk of overweight/obesity in early childhood. Similar results were observed among LGA infants of mothers with GDM. Conclusions: Initiating and prolonging breastfeeding would reduce the risk of overweight/obesity in early childhood, and LGA infants and infants born to mothers with GDM would experience greater benefits.