Secular trends and sociodemographic determinants of thinness, overweight and obesity among Chinese children and adolescents aged 7-18 years from 2010 to 2018

Predicting the onset of overweight in Chinese high school students: a machine-learning approach in a one-year prospective cohort study

OBJECTIVE

This study aimed to develop and evaluate machine-learning models for predicting the onset of overweight in adolescents aged 14‒17, utilizing easily collectible personal information.

METHODS

This study was a one-year prospective cohort study. Baseline data were collected through anthropometric measurements and questionnaires, and the incidence of overweight was calculated one year later via anthropometric measurements. Predictive factors were selected through univariate analysis. Six machine-learning models were developed for predicting the onset of overweight. The SHapley Additive exPlanations (SHAP) was used for global and local interpretation of the models.

RESULTS

Out of 1,241 adolescents, 204 (16.4%) were identified as overweight after one year. Nineteen features were associated with the overweight incidence in univariable analysis. Participants were randomly divided into a training group and a testing group in a 7:3 ratio. The Light Gradient Boosting Machine (LGBM) algorithm achieved outperformed other models, achieving the following metrics: Accuracy (0.956), Recall (0.812), Specificity (0.983), F1-score (0.855), AUC (0.961). Importance ranking revealed that the top 11 minimal feature set can maintain the stability of model performance.

CONCLUSIONS

The onset of overweight in adolescents was accurately predicted using easily collectible personal information. The LGBM-based model exhibited superior performance. Oversampling technique notably improved model performance. The model interpretation technique provided innovative strategies for managing adolescent overweight/obesity.

Trends in Undernutrition among Macao Children and Adolescents Aged 7~18 Years: An Analysis from Four Successive Macau Government Surveys from 2005 to 2020

Background

We aimed to explore the epidemiological trends and characteristics of undernutrition among children and adolescents aged 7~18 years in Macao from 2005 to 2020 to provide insights into the improvement of nutritional status among the youth in Macao, China.

Methods

Based on the data collected from the Citizen Physical Fitness surveillance sessions in Macao in 2005, 2010, 2015, and 2020, the prevalence of undernutrition among children and adolescents aged 7~18 years in Macao was calculated.

Result

In 2020, the prevalence of undernutrition among children and adolescents aged 7~18 years in Macao was 12.11%. Among them, the rates of stunting, moderate or severe wasting, and mild wasting were 0.63%, 5.25%, and 6.23%, respectively. The prevalence of undernutrition among boys (13.81%) was higher than that among girls (10.06%). Mild wasting was the main form of undernutrition among students. From 2005 to 2020, the prevalence of malnutrition showed a decreasing trend (P<0.05), but there was a rebound in 2020 from 2015, mainly because it may be caused by the COVID-19 pandemic in 2020. The prevalence of undernutrition among children and adolescents in Macao was lower than that in Mainland China (P<0.01).

Conclusion

The detection rates of undernutrition showed a decreasing trend from 2005 to 2020. In the post-pandemic era, Macao should undertake more effective measures in areas such as promoting balanced nutritional intake, increasing physical activity levels, enhancing school physical education, and incorporating mental health education. These efforts are essential for further reducing the prevalence of undernutrition among children and adolescents.

Secular trends and urban-rural disparities in height of Chinese adolescents aged 18 years from 1985 to 2019

OBJECTIVES

To examine the secular trends and urban-rural disparities in height of Chinese adolescents aged 18 years from 1985 to 2019.

METHODS

Data were extracted from the Chinese National Surveys on Students' Constitution and Health from 1985 to 2019, and the heights of a total of 76 554 boys and 75 908 girls aged 18 years were measured. The Mann-Kendall trend test was used to analyze the secular trends in height. Changes in different periods and urban-rural disparities were tested by z-tests and calculating the ratios of the coefficient of variation (CV) of height.

RESULTS

The height of Chinese boys and girls aged 18 years increased from 168.21 and 157.10 cm in 1985 to 172.15 cm and 160.11 cm in 2019, respectively, with a larger increase in rural areas. The secular trends in height were the largest for boys from 1995 to 2005 and for girls from 2014 to 2019, and the same results were observed in urban and rural areas. The urban-rural disparities for boys and girls decreased by 1.79 and 0.91 cm, respectively, with significant decreases for boys in all regions and for girls in the eastern region. The overall CVs of height increased by 0.13% and 0.25% for boys and girls, respectively, with the largest increase among rural girls.

CONCLUSIONS

The height of Chinese adolescents aged 18 years continued to increase between 1985 and 2019. The urban-rural disparities narrowed, and inequalities within rural areas for girls increased.

Association between Dietary Behavior and Overweight and Obesity among Chinese Students: A Cross-Sectional Study

OBJECTIVES

To investigate the prevalence of overweight and obesity among Ningbo students and explore the association between students' dietary behavior and overweight and obesity.

MATERIALS AND METHODS

A total of 7299 students were recruited, including 3755 males and 3544 females. A questionnaire on student health status and influencing factors was used to investigate dietary behavior. Logistic regression analysis investigated the relationship between dietary behavior and overweight and obesity. Age, gender, area, grade, sleep duration, and physical activity were adjusted in the multivariate regression models.

RESULTS

This study revealed that the prevalence of overweight and obesity in Ningbo students was 16.14% and 9.88%, respectively. The logistic regression analysis results showed that regular consumption of sugary beverages was associated with a higher risk of being overweight (OR = 1.256, 95% CI: 1.023-1.542, p = 0.029). The research indicated that skipping breakfast was considered a risk factor for obesity (OR = 2.102, 95% CI: 1.087-4.065, p = 0.027). After adjusting for age, gender, area, and grade and continuing to adjust for sleep duration and physical activity, the results showed that consuming fried food at least once a day increased the risk of obesity (OR = 1.494, 95% CI: 1.050-2.125, p = 0.026; OR = 1.516, 95% CI: 1.065-2.158, p = 0.021, respectively). This study found that the frequency of breakfast and the consumption of fried food, fresh vegetables, and fruits were not significantly associated with being overweight (p > 0.05).

CONCLUSIONS

This study indicated that dietary behavior was related to overweight and obesity among Ningbo students. Further studies and more government support are required to confirm this study's findings and address the current overweight/obesity problems.