The impacts of free school lunch policies on adolescent BMI and mental health: Evidence from a natural experiment in South Korea

Impact of Covid-19 lockdowns on the anthropometric development in primary school children in the Rhein-Neckar Region, Germany

BACKGROUND

Published data suggests that lockdowns during the COVID-19 pandemic may have negatively affected children's weight development. This study aims to assess the prevalence of overweight and obesity after the COVID-19 lockdowns as well as anthropometric development among primary school children in the Rhein-Neckar Region, Germany.

METHODS

In this cross-sectional study, schools were selected in cooperation with the local health authority to include different socioeconomic backgrounds. Participation was voluntary at school and individual level, requiring written informed consent from legal guardians. Study visits in schools were conducted between October 2021 and July 2022. Anthropometric data from nationally recommended medical examinations at 4 years (U8) and 5 years (U9), data on nutrition, physical activity, and socioeconomic data was collected using questionnaires. zBMI and weight category were calculated based on German reference data.

RESULTS

256 children with a mean age of 8.0 years (7.1-9.3 years) were included in the study. Most participants were from households with an above average income. 5.1% of the children were overweight, 4.7% were obese, 15.6% were underweight, and 74.6% were normal weight with a mean zBMI of -0.25 (SD 1.10), which is significantly lower than the mean zBMI of the German reference population (p < 0.001). No significant changes in zBMI were observed between U8 and U9 (p = 0.16). The mean zBMI decreased by 0.17 (SD 0.72) between U9 and the study visit (p = 0.02). A zBMI decrease of 0.5 was documented for the subgroup of overweight and obese children (p = 0.028) as well as a decrease of 0.23 (SD 0.63) for the normal-weight children subgroup (p < 0.001).

CONCLUSIONS

Contrary to previous reports mean zBMI decreased significantly in the children studied. No significant changes in zBMI were observed between U8 and U9 examinations, which supports the hypothesis that the decrease in zBMI could be attributed to lockdown measures. The study was registered at clinicaltrials.gov on September 21st 2021 under the registration number NCT05077059.

Universal Free School Meals Policy and Childhood Obesity

BACKGROUND AND OBJECTIVES

The Community Eligibility Provision (CEP), a universal free school meals policy, increases school meal participation by allowing schools in low-income areas to provide free breakfast and lunch to all students; however, its impact on obesity remains uncertain. The objective of this study is to estimate the association of CEP with child obesity.

METHODS

School obesity prevalence was calculated using BMI measurements collected annually between 2013 and 2019 from students in California public schools in grades 5, 7, and 9. To estimate the association of CEP with obesity, we used a difference-in-differences approach for staggered policy adoption with an outcome regression model conditional on covariates, weighted by student population size.

RESULTS

The analysis included 3531 CEP-eligible schools using school-level obesity prevalence calculated from 3 546 803 BMI measurements. At baseline, on average, 72% of students identified as Hispanic, 11% identified as white, 7% identified as Black, and 80% were eligible for free or reduced-price meals. Baseline obesity prevalence was 25%. Schools that participated in CEP were associated with a 0.60-percentage-point net decrease in obesity prevalence after policy adoption (95% confidence interval: -1.07 to -0.14 percentage points, P = .01) compared with eligible, nonparticipating schools, corresponding with a 2.4% relative reduction, given baseline prevalence. Meals served increased during this period in CEP-participating schools only.

CONCLUSIONS

In a balanced sample of California schools, CEP participation was associated with a modest net decrease in obesity prevalence compared with eligible, nonparticipating schools. These findings add to the growing literature revealing potential benefits of universal free school meals for children's well-being.

Do community-related traumatic events affect academic outcomes among adolescents? Quasi-experimental evidence from the Sewol disaster in South Korea

The sinking of the South Korean ferry Sewol in April 2014 claimed a total of 304 lives. Among the victims were 250 students from Dan-won High School in the city of Ansan and 11 of their teachers. For the residents of Ansan, the tragedy marked the beginning of widespread psychological distress and overwhelming grief. Exploiting the disaster's quasi-experimental nature, we employ a difference-in-differences (DID) strategy to measure its impact on the academic performance of Ansan's high school students in 5 major subjects. Using peers from Ansan's neighboring cities as the control group, our results reveal that the disaster impaired performances particularly in mathematics and natural science, a finding that is more pronounced for female students. Our results highlight that it is of uttermost importance to provide comprehensive psychological support and interventions to traumatized students but also to the communities they live in to minimize adverse effects on educational attainment.

Does the integration of urban and rural health insurance influence the functional limitations of the middle-aged and elderly in rural China?

In January 2016, the Chinese government integrated the two systems of urban resident basic medical insurance and new rural cooperative medical system to establish a unified Urban and Rural Resident Medical Insurance. The integration of medical insurance is purported to enhance access for the rural population; however, a dearth of literature exists regarding its effect on functional impairment among middle-aged and elderly residing in rural areas. This study aims to evaluate the impact of urban-rural health insurance integration on functional limitation among middle-aged and elderly individuals in rural China. A longitudinal survey was conducted among 7855 middle-aged and elderly individuals in rural China. Using a nonequivalent control group pretest-posttest design, we exploit these policy changes to evaluate their impact on middle-aged and elderly individuals' functional limitation. The results showed that the integration of urban and rural health insurance systems was significantly associated with reduced functional limitation (Odds ratio .742; 95%CI 0.603, 0.914) among middle-aged and elderly individuals in rural China. Our findings also indicate that prevalent behaviors such as tobacco use, and alcohol consumption may exacerbate functional limitation among middle-aged and elderly individuals. These findings suggest that the integration of urban and rural health insurance systems can have a positive impact on the functional limitation of middle-aged and elderly individuals in rural China and could be an important factor in improving the health and well-being of middle-aged and elderly individuals in rural areas.

Age at menarche of adolescent girls and the neighbourhood socioeconomic status of their school area

PURPOSE

To assess the association between abnormal timing of menarche among adolescent girls and neighbourhood socioeconomic status of their school area.

MATERIALS AND METHODS

Our analysis included 187,024 girls aged 15-18 years from the Korea Youth Risk Behaviour Web-Based Survey (KYRBS) from 2007 to 2015. Early and late menarche were defined as menarche before 11 years and no menarche by age 14 years, respectively. The deprivation index values for the areas where the schools were located were used as an indicator of neighbourhood socioeconomic status based on the 2005 national census data. We calculated odds ratios (OR) for early and late menarche using a multinomial logistic regression model. Covariates included body mass index, parental education, single or stepparents, siblings, household wealth, year of birth, survey year, and urbanisation.

RESULTS

Mean age at menarche was 12 years. The overall proportions of early and late menarche were 11.3% and 3.3%, respectively. When divided into four quartile groups based on the socioeconomic deprivation index, 11.3% of girls in the most deprived quartile and 10.6% in the least deprived area showed early menarche. The prevalence of late menarche did not differ across the deprivation index quartiles of school area. Attendance at schools located in highly deprived areas was associated with up to 10% higher risk of early menarche. This positive association was not evident for late menarche.

CONCLUSION

Among contemporary Korean girls, socioeconomic deprivation of the school area was associated with earlier puberty. This finding highlights the potential role of the socioeconomic environment of schools in women's lifetime health.

Associations between School Lunch and Obesity in Korean Children and Adolescents Based on the Korea National Health and Nutrition Examination Survey 2017-2019 Data: A Cross-Sectional Study

Obesity in children and adolescents is a serious global problem. In Korea, approximately 35% of students' daily nutrient intake is from school lunch (SL), and all schools provide SL. However, the association between SL and obesity remains controversial. This study examined this association and the daily nutrient intake according to lunch type in Korean children and adolescents. We analyzed 1736 individuals aged 7-18 from the Korea National Health and Nutrition Examination Survey (2017-2019), a cross-sectional study, using logistic regression analysis with odds ratios and 95% confidence intervals. The SL group had higher energy and greater phosphorus, potassium, vitamin A, carotene, vitamin B1, and niacin intake than the non-school lunch (NSL) and skipping lunch (SKL) groups. Protein intake was also higher in the SL group than in the NSL group. The SKL group had higher saturated fatty acid intake, and was thereby 2.5, 1.9, and 2.5 times more likely to have obesity, overweight and obesity, and central obesity (p = 0.0071, 0.0459, 0.0092), respectively, than the SL group. Therefore, the SL group consumed more appropriate nutrients than the NSL and SKL groups, and was less likely to become obese than the SKL group. More in-depth prospective studies are needed to elucidate the causal relationship between SL and obesity.

Discrete-time Survival Analysis of Risk Factors for Early Menarche in Korean Schoolgirls

OBJECTIVES

The aim of this study was to evaluate the effect of body weight status and sleep duration on the discrete-time hazard of menarche in Korean schoolgirls using multiple-point prospective panel data.

METHODS

The study included 914 girls in the 2010 Korean Children and Youth Panel Study who were in the elementary first-grader panel from 2010 until 2016. We used a Gompertz regression model to estimate the effects of weight status based on age-specific and sex-specific body mass index (BMI) percentile and sleep duration on an early schoolchild's conditional probability of menarche during a given time interval using general health condition and annual household income as covariates.

RESULTS

Gompertz regression of time to menarche data collected from the Korean Children and Youth Panel Study 2010 suggested that being overweight or sleeping less than the recommended duration was related to an increased hazard of menarche compared to being average weight and sleeping 9 hours to 11 hours, by 1.63 times and 1.38 times, respectively, while other covariates were fixed. In contrast, being underweight was associated with a 66% lower discrete-time hazard of menarche.

CONCLUSIONS

Weight status based on BMI percentiles and sleep duration in the early school years affect the hazard of menarche.