Effect of adding milk to a micronutrient fortified high-energy biscuit school feeding programme in Yemen: A cluster-randomised controlled trial

Bliznashka, Lilia; Michail, Monica George; Elsabbagh, Dalia; Gelli, Aulo; and the School Milk Initiative. Effect of adding milk to a micronutrient fortified high-energy biscuit school feeding programme in Yemen: A cluster-randomised controlled trial. SSRN Preprint. First available online on April 2, 2025. https://doi.org/10.2139/ssrn.5196994

Background: Two billion children globally are estimated to live in conflict-affected areas. School feeding programmes (SFPs) are a widely implemented safety net that supports children during and after conflict. We evaluated the effectiveness of providing milk alongside a high energy biscuits (HEBs) SFP in Yemen on children’s and caregivers’ outcomes.

Methods: We implemented a two-arm longitudinal cluster-randomised controlled trial from December 2023 to May 2024. 42 schools in Al Mukha district were randomly assigned (1:1) to: control, where children received HEBs (2 packets (100 grams) daily), or milk, where children received HEBs plus a 120 ml carton of ultra-high temperature milk. Children aged 6-18 years were randomly selected for enrolment. The primary outcomes were children’s dietary diversity and milk consumption. Secondary outcomes were children’s cognition, learning, attendance, nutritional status, and health. Tertiary outcomes were child and caregiver mental health, and household food security. We conducted intent-to-treat analysis using linear mixed effects models adjusting for clustering. The trial was registered with ISRCTN (ISRCTN12225603).

Findings: 1,299 children were enrolled. After five months, the intervention increased milk consumption, but had no effect on dietary diversity. Children’s cognition [mean difference (MD) 1.00 (95% CI 0.40, 1.61)], literacy [1.14 (0.36, 1.92)], and numeracy [1.06 (0.46, 1.67)] scores improved. Cough symptoms declined: -0.12 (-0.2, -0.03). There was no effect on school attendance or nutritional status. The intervention reduced conduct problems in children [-0.52 (-0.97, -0.08)], severe anxiety in caregivers [-0.03 (-0.06, -0.001)], and household severe food insecurity [-0.09 (-0.17, -0.001)].

Interpretation: Adding a daily milk drink to an HEB SFP in Yemen resulted in numerous benefits for children and their families. Hybrid models to incrementally improve meal quality are feasible, acceptable, and lead to meaningful impacts. More research is needed on medium- and long-term benefits.