每天一个苹果：更健康的校餐对约旦儿童的影响（英）

An Apple a Day The Impact of Healthier School Mealson Children in Jordan Simone LombardiniFlorence KondylisBenedetta LervaJonas HeirmanRoshni KhinchaHannah Uckat Development EconomicsDevelopment Impact GroupSeptember 2025 A verified reproducibility package for this paper isavailable athttp://reproducibility.worldbank.org,clickherefor direct access. Policy Research Working Paper11208 Abstract Poor nutritional choices and unhealthy behaviors are con-sidered responsible for the rise in childhood overweight andobesity and may reinforce each other, creating a viciouscycle. This paper studies a primary school interventiondesigned to break the cycle early in life by replacing datebars with calorie-equivalent meals lower in sugar and fat. Leveraging the randomized pilot of a menu change in Jor-dan’s national school feeding program, the study shows thatchildren consuming the alternative meals spend 8 percentless money to buy processed snacks, are more physicallyactive (0.1 standard deviation), and go to school one extraday per year. This paper is a product of the Development Impact Group, Development Economics. It is part of a larger effort by theWorld Bank to provide open access to its research and make a contribution to development policy discussions around theworld. Policy Research Working Papers are also posted on the Web at http://www.worldbank.org/prwp. The authors may becontacted at huckat@worldbank.org. A verified reproducibility package for this paper is available athttp://reproducibility.worldbank.org, clickherefor direct access. The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about developmentissues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry thenames of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely thoseof the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank andits affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent. An Apple a DayThe Impact of Healthier School Meals onChildren in Jordan∗ r○Simone Lombardini†Florence Kondylis‡Benedetta Lerva‡Jonas Heirman†Roshni Khincha‡Hannah Uckat‡ Keywords: school feeding, experiment, nutrition, education JEL Codes: I15, I25, O12, O15 1Introduction The type and quality of food we eat every day, especially during childhood, has short-and long-term consequences on almost every aspect of our life (Gertler and Gracner,2022). In addition to impacting physical health, nutrition also affects our behaviors (Listand Samek, 2015). Poor nutritional choices and unhealthy behaviors are often observedtogether (Dowda et al., 2001); the increased consumption of processed (high-fat andsugary) food items and a sedentary lifestyle are together considered responsible for thegrowing share of obese and overweight people among all income classifications and all agegroups (WHO, 2025). Overweight and obesity have documented individual and social costs.Individualswho are overweight or obese have poorer physical and mental health, lower learning, andlower incomes later in life (Cawley, 2004; Gertler and Gracner, 2022); societies with highincidence of overweight and obese citizens can expect higher health care expenditure andproductivity losses (GBD, 2020; Okunogbe et al., 2021; Trasande and Chatterjee, 2009).Because dietary habits persist in adulthood, breaking the cycle early in life may havehigh private and public returns (Campbell et al., 2007; Bourdeaudhuij, 1997). In this paper, we investigate whether meals with an improved macronutrient balancegive children a healthy start. Specifically, we document the causal link between the pro-vision of alternative meals, containing less sugar and fat and more protein, and outcomesincluding nutritional behaviors, physical activity, school attendance, and learning amongprimary school children in Jordan.Like most other low- and middle-income countries,Jordan is affected by the double burden of malnutrition characterized by both undernu-trition and high rates of overweight and obesity1(Popkin et al., 2020). The World FoodProgramme and World Bank partnered with Jordan’s Ministry of Education to layer arandomized controlled trial onto the pilot of a menu change in Jordan’s National SchoolFeeding Program. It compares the status quo, a date bar with high sugar content, to acalorie-equivalent local meal including a cheese pastry, a fruit, and a vegetable, which istherefore higher in protein and lower in sugar and fat (following program language, werefer to this as theHealthy Meal). The newly introduced meal is designed to increase thedietary diversity among children who, in our sample, typically eat less than five of ninerecommended food groups. Our trial inclu