A Meta-Analysis of the Association Between Breastfeeding and Early Childhood Obesity

Problem: Several studies have indicated a protective effect of breastfeeding on reducing the risk of childhood obesity, however, this remains controversial. The aim of this meta-analysis is to clarify the association between breastfeeding and the risk of preschoolers' obesity. Eligibility criteria: Prospective cohort studies published prior to December 1, 2019 were systematically searched in PubMed, EMBASE, the Web of Science and the Cochrane Library databases. Meta-analysis was performed using Stata 15.1. Sample: Twenty-six publications involving 332,297 participants were eligible for inclusion. Results: The pooled odds ratio (OR) of the risk of obesity in ever-breastfed preschoolers was 0.83 (95%CI [0.73,0.94]) compared with their never-breastfed counterparts. Random-effects dose-response model revealed a negative correlation between the duration of breastfeeding and risk of obesity (regression coef ficient =-0.032, p = .001). Categorical analysis con firmed this dose-response association (1 day to <3 months of breastfeeding: OR = 1.07, 95%CI [0.94,1.21]; 3 months to <6 months: OR = 0.96, 95%CI [0.60,1.54]; ?6 months: OR = 0.67, 95%CI [0.58,0.77]). One month of breastfeeding was associated with a 4.0% decrease in risk of obesity (OR = 0.96/month of breastfeeding, 95% CI [0.95, 0.97]). Under the reference of never breastfeeding, the summary OR of exclusive breastfeeding was 0.53 (95%CI [0.45,0.63]). Conclusions: Breastfeeding is inversely associated with a risk of early obesity in children aged two to six years. Moreover, there is a dose-response effect between duration of breastfeeding and reduced risk of early childhood obesity. Implications: Clinical nurses' guidance and advice that prolong the duration of breastfeeding and promote exclusive breastfeeding are needed to prevent the development of later childhood obesity. (C) 2020 Published by Elsevier Inc.