A new study led by Professor Sayaka Nakamura from Sophia University in Japan and Professor Shiko Maruyama from Jinan University in China published in the journal Health Economics reveals the significant positive impact of the Japanese school lunch program on the weight of early teenagers. The research, titled "Wholesome Lunch to the Whole Classroom: Short- and Longer-Term Effects on Early Teenagers’ Weight," found that the program effectively reduces Body Mass Index (BMI), Percent Overweight (POW), and obesity rates , particularly among students from lower socioeconomic backgrounds.
Child obesity is a growing public health crisis worldwide. In response, many countries have implemented school nutrition reforms. This study offers a unique opportunity to evaluate the direct effect of a universal school lunch program by examining data from Japan, where all children attending schools providing lunch are required to participate. This differs from programs in countries like the UK and the US, which often have eligibility criteria.
The researchers employed a rigorous difference-in-differences (DID) analysis using data from the National Nutrition Survey (NNS) spanning from 1975 to 1994. This method compared changes in weight among students in municipalities with and without universal junior-high school lunch programs. The study also utilized propensity score weighting and various falsification tests to ensure the reliability of its findings.
Key findings of the study include:
While the direct weight reduction effect appears to wane after students graduate from junior high school, the study's findings underscore the significant short-term benefits of universal school lunch programs in addressing child obesity, especially for vulnerable populations. These results have important implications for policymakers considering strategies to improve child health and reduce socioeconomic inequalities.
Health Economics
Wholesome Lunch to the Whole Classroom: Short- and Longer-Term Effects on Early Teenagers’ Weight
18-Mar-2025