Testing methods to increase consumption of healthy foods: Evidence from a school-based field experiment in Viet Nam

Schools are an attractive entry point to improve children’s diets, as their eating habits can be shaped during childhood and the information disseminated from school can reach adults through children. We implemented a cluster-randomized trial in 12 schools in peri-urban Viet Nam to assess if two school-based interventions increased knowledge of healthy diets among children and their parents, as well as children’s consumption of healthy foods. First, children were given lessons about food before school lunch and encouraged to share the lessons with their parents. Second, children were provided with healthy snacks for five weeks to reinforce messages about healthy eating. We found that in the short term, the nutrition lessons raised the knowledge index score of the children by 0.35 standard deviation. After six months, this intervention retained its effectiveness only for the children who also received free access to fruit, emphasizing the linkage between knowledge and practice. By itself, free access to fruit at school increased the children’s daily fruit consumption by half a portion, but not at the expense of home fruit consumption. Access to healthy foods at school can therefore be an effective measure to raise children’s healthy consumption. Child-parent communication was not a reliable channel for knowledge dissemination in our setting.