Preventive lipid-based nutrient supplements given with complementary foods to infants and young children 6 to 23 months of age for health, nutrition, and developmental outcomes.

Systematic review and meta-analysis of preventive LNS trials in non-hospitalised infants and young children aged 6 to 23 months, mainly in low- and middle-income countries in Africa and Asia. Several included trials enrolled pregnant women and mother-infant pairs, but the main target population was the child age group receiving complementary foods.

Preventive lipid-based nutrient supplements were given with complementary foods, typically as a daily 20 g sachet for about 118 kcal/day, although some earlier trials used 20 g/day providing 108 kcal/day in different LNS formulations. Across trials, the intervention generally lasted from several months through 6 to 18 months of age, with some studies showing greater benefit when supplementation continued longer than 12 months.

LNS plus complementary feeding improved growth and reduced anaemia versus no intervention, without evidence of increased adverse effects. One pooled growth result showed reduced moderate stunting at 12, 18, or 24 months across nine studies (RR 0.93, 95% CI 0.88 to 0.98). Benefits were larger when the intervention lasted longer than 12 months. Evidence that LNS was more effective than fortified blended foods or micronutrient powders was limited, and psychomotor or neurodevelopmental findings were mixed.

The evidence base was heterogeneous, with differences in LNS formulations, doses, duration, and co-interventions across trials. Some outcomes, especially psychomotor and neurodevelopmental measures, were inconsistently reported or not pooled, limiting certainty. Comparative evidence versus fortified blended foods or micronutrient powders was limited, and several findings are indirect across diverse LMIC settings.