Background: Supplementary feeding is defined as the provision of extra food to children or families beyond the normal ration of their home diets. The impact of food supplementation on child growth merits careful evaluation in view of the reliance of many states and non-governmental organisations on this intervention to improve child health in low and middle income countries (LMIC). This is an update of a Cochrane review first published in 2005.
Objectives: To evaluate the effectiveness of community-based supplementary feeding for promoting the physical growth of children under five years of age in LMIC.
Search methods: For this updated review we searched the following databases on 31 January 2011: CENTRAL (The Cochrane Library), MEDLINE (1948 to January week 3, 2011), EMBASE (1980 to week 3, 2011), CINAHL (1937 to 27 January 2011), LILACS (all years), WorldCat for dissertations and theses (all years) and ClinicalTrials.gov (all years).
Selection criteria: Randomised controlled trials (RCTs) evaluating supplementary feeding in comparison to a control group (no intervention or a placebo such as food with a very low number of nutrients and calories) in children from birth to five years of age in LMIC.
Data collection and analysis: Two review authors independently extracted and analysed the data.
Main results: We included eight RCTs (n = 1243 children) that were at relatively high risk of bias. We found high levels of clinical heterogeneity in the participants, interventions and outcome measures across studies. Nevertheless, in order to quantify pooled effects of supplementary feeding, we decided to combine studies according to prespecified characteristics. These were the children's age (younger or older than 24 months), their nutritional status at baseline (stunted or wasted, or not stunted or wasted) and the duration of the intervention (less or more than 12 months). A statistically significant difference of effect was only found for length during the intervention in children aged less than 12 months (two studies; 795 children; mean difference 0.19 cm; 95% confidence interval (CI) 0.07 to 0.31). Based on the summary statistic calculated for each study, the mean difference (MD) between intervention and control groups ranged from 0.48 cm (95% CI 0.07 to 0.89) to 1.3 cm (95% CI 0.03 to 2.57) after 3 and 12 months of intervention, respectively. Data on potential adverse effects were lacking.
Authors' conclusions: The scarcity of available studies and their heterogeneity makes it difficult to reach any firm conclusions. The review findings suggest supplementary feeding has a negligible impact on child growth; however, the pooled results should be interpreted with great caution because the studies included in the review are clinically diverse. Future studies should address issues of research design, including sample size calculation, to detect meaningful clinical effects and adequate intervention allocation concealment. In the meantime, families and children in need should be provided appropriate feeding, health care and sanitation without waiting for new RCTs to establish a research basis for feeding children.