Effectiveness of dietary interventions on weight outcomes in childhood: a systematic review meta-analysis of randomized controlled trials

Abstract

Background: Rapid growth and elevated weight in childhood are significantly associated with obesity in later life, but evidence regarding dietary interventions and weight outcomes is lacking. This study aimed to determine the effectiveness of dietary interventions on body mass index (BMI) and BMI z-score in childhood. Methods: PubMed, EmBase, and the Cochrane library were searched from inception till June 2019. Studies that investigated the effectiveness of dietary interventions on BMI and BMI z-score in childhood were considered eligible in our study. The changes in BMI and BMI z-score between dietary interventions and control were calculated by pooled weighted mean differences (WMDs) and 95\% CIs were evaluated using random-effects model. Results: Twenty-eight randomized controlled trials involving a total of 17,488 children were included. The summary WMDs indicated that children who received dietary interventions had greater reduction in BMI (WMD: -0.12; 95\% CI: -0.20 to -0.05; P=0.001) and BMI z-score (WMD: -0.04; 95\% CI: -0.06 to -0.02; P=0.001) when compared to the usual controls. Subgroup analyses revealed that the sample size, mean age, duration of interventions, and study quality could affect the effectiveness of dietary interventions in children. Conclusions: The findings of this meta-analysis suggested that dietary interventions improved BMI and BMI z-score, whereas these results are limited due to substantial heterogeneity and study quality of the included studies.