Exclusive breastfeeding and partial breastfeeding reduce the risk of overweight in childhood: A nationwide longitudinal study in Korea.

OBJECTIVE

Breastfeeding is generally known to reduce the risk of childhood overweight and obesity. However, the results are controversial between countries, and nationwide data are rare. This study assessed the relationship between breastfeeding types and overweight incidence using nationwide longitudinal data in Korea.

METHODS

We analysed 774,764 infants who participated in the longitudinal nationwide data from the Korea National Children's Health Examination 2007-2013. Childhood overweight was defined by a Z-score≥1.64 (95th centile) for infants under 24 months and Z-scores≥1.04 (85th centile) for children over 24 months. Cox proportional hazard model was used to analyse the relationship between breastfeeding types and overweight incidence.

RESULTS

Infants who were exclusively breastfed at 4-6 months of age had the multivariate-adjusted hazard ratio (HRs) for overweight of 0.78 (95% CI 0.77-0.79) and infants who were partially breastfed had the HRs for overweight of 0.96 (95% CI 0.94-0.98), which was lower compared to that of the exclusively formula fed group. Similar results were obtained for stratified analysis by boys and girls.

CONCLUSIONS

Exclusive and partial breastfeeding have preventive effect on childhood overweight in Korea. Therefore, it is necessary to encourage breastfeeding to prevent childhood obesity and its consequences in developed Asian countries.