Complementary feeding interventions have a small but significant impact on linear and ponderal growth of children in low- and middle-income countries: A systematic review and meta-analysis

Background: World Health Assembly member states have committed to ambitious global targets for reductions in stunting and wasting by 2025. Improving complementary diets of children aged 6-23 mo is a recommended approach for reducing stunting in children < 5 y old. Less is known about the potential of these interventions to prevent wasting. Objective: The aim of this article was to review and synthesize the current literature for the impact of complementary feeding interventions on linear [length-for-age z score (LAZ)] and ponderal [weight-for-length z score (WLZ)] growth of children aged 6-23 mo, with the specific goal of updating intervention-outcome linkages in the Lives Saved Tool (LiST). Methods: We started our review with studies included in the previous LiST review and searched for articles published since January 2012. We identified longitudinal trials that compared children aged 6-23 mo who received 1 of 2 types of complementary feeding interventions (nutrition education or counseling alone or complementary food supplementation with or without nutrition education or counseling) with a no-intervention control. We assessed study quality and generated pooled estimates of LAZ and WLZ change, as well as length and weight gain, for each category of intervention. Results: Interventions that provided nutrition education or counseling had a small but significant impact on linear growth in food-secure populations [LAZ standardized mean difference (SMD): 0.11; 95% CI: 0.01, 0.22] but not on ponderal growth. Complementary food supplementation interventions with or without nutrition education also had a small, significant effect in food-insecure settings on both LAZ (SMD: 0.08; 95% CI: 0.04, 0.13) and WLZ (SMD: 0.05; 95% CI: 0.01, 0.08). Conclusions: Nutrition education and complementary feeding interventions both had a small but significant impact on linear growth, and complementary feeding interventions also had an impact on ponderal growth of children aged 6-23 mo in low- and middle-income countries. The updated LiST model will support nutrition program planning and evaluation efforts by allowing users to model changes in intervention coverage on both stunting and wasting.