Secular growth trends among children in Beijing (1955-2010)

Secular trends in height, weight, and body mass index in the context of economic and political transformations in Russia from 1885 to 2021

OBJECTIVES

To study and analyze the impact of socio-economic factors on secular changes in height, weight, and body mass index (BMI) among Moscow's youth over the time interval from the late 19th-early 20th century to the present.

METHODS

Anthropometric data, including height, weight, and BMI, were collected through surveys conducted on youths aged 17-20 years in Moscow from the 1880s for males and from the 1920s for females to the present. The dataset includes information on 6434 individuals surveyed from 2000 to 2019, as well as previously published mean values. Economic development indicators, such as gross domestic product (GDP) per capita, monthly average income per capita, and the Gini coefficient, were examined to analyze the association between secular trends in body size and socio-economic conditions.

RESULTS

A positive secular trend in height and weight has been observed among Moscow's youth from the early 20th century to the present. Substantial increases in height occurred during the second half of the previous century, stabilizing in the 2000s. Over the analyzed period, both average body weight and BMI values showed a consistent rise. The pattern for BMI exhibited a U-shaped trend, with a decline from the 1970s to the mid-1990s, followed by a subsequent increase. Strong correlations were found between the secular changes in body size among Moscow's youth and temporal fluctuations in key socio-economic indicators, including GDP per capita, monthly average income per capita, and the Gini coefficient.

CONCLUSION

The study demonstrates the significant influence of socio-economic conditions on intergenerational changes in body size, as evidenced by the positive secular trend in physique indicators (height, weight, and BMI) among Moscow's youth.

Construction of a new complete growth reference for urban Chinese children

Background

Growth chart is a valuable clinical tool to monitor the growth and nutritional status of children. A growth chart widely used in China is based on the merged data sets of national surveys in 2005. We aimed to establish an up-to-date, complete growth curve for urban Chinese children and adolescents with a full range of ages.

Methods

Using data collected in a large-scale, cross-sectional study (Prevalence and Risk factors for Obesity and Diabetes in Youth (PRODY), 2017–2019), we analyzed 201,098 urban children aged 3 to 18 years from 11 provinces, autonomous regions, and municipalities that are geographically representative of China. All participants underwent physical examinations. Sex-specific percentiles of height-for-age and weight-for-age were constructed by Generalized Additive Models for Location Scale and Shape (GAMLSS) model. We also compared the median values of height-for-age or weight-for-age between our growth chart and the established growth reference using Welch-Satterthwaite T-Test.

Results

Consistent with the established growth reference, we observed that the P₅₀ percentile of height-for-age reached plateaus at the age of 15 years (172 cm) and 14 years (160 cm) for boys and girls, respectively. In addition, boys aged 10 ~ 14 years and girls aged 10 ~ 12 years exhibited the most dramatic weight difference compared to those of other age groups (19.5 kg and 10.3 kg, respectively). However, our growth chart had higher median values of weight-for-age and height-for-age than the established growth reference with mean increases in weight-for-age of 1.36 kg and 1.17 kg for boys and girls, respectively, and in height-for-age of 2.9 cm and 2.6 cm for boys and girls, respectively.

Conclusions

Our updated growth chart can serve as a reliable reference to assess the growth and nutritional status in urban Chinese children throughout the entire childhood.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14702-8.

Trends in growth and nutritional status of high school graduates in Hangzhou, China, 2011-2020

Background

During past decades, there was a positive trend in growth and nutrition status of adolescents in China, but there was significant regional disparity. The purpose of this study is to investigate the trends in growth and nutritional status of high school graduates in Hangzhou between 2011 and 2020.

Methods

High school graduates (Grade 12) who finished the physical examination of the national college entrance examination between 2011 and 2020 (n=481,353)were included in this study. Data were obtained from the database of physical examination of the national college entrance exam. Height and weight were measured; body mass index (BMI) was calculated from height and weight. Thinness, overweight and obesity were defined according to the International Obesity Task Force criteria. For the vast majority of the high school graduates were 18 years old or nearly 18 years old, the cutoffs of 18 years were adopted. Those are 18.5, 25 and 30 kg/m², for thinness, overweight and obesity respectively.

Results

There was a significant growth trend in height, weight and BMI in both sexes (P < 0.001). Height increased by 1.80 cm in boys and 1.45 cm in girls. Weight increased by 4.62 kg in boys and 2.51 kg in girls. BMI increased by 1.09 kg/m² in boys and 0.60 kg/m² in girls. An increase trend was found in the prevalence of overweight and obesity in both sexes (P < 0.001). Overweight increased by 7.43% (from 9.05 to 16.48%) among boys and 4.05% (from 4.57 to 8.62%) among girls. Obesity increased by 3.85% (from 2.29 to 6.14%) among boys and 1.76% (from 0.64 to 2.40%) among girls. The prevalence of thinness fluctuated in both boys and girls, 12.42–15.59% among boys and 18.97–23.68% among girls. Boys had higher odds of overweight and obesity and lower odds of thinness than girls (P < 0.001).

Conclusions

There is a positive trend in growth and nutritional status of high school graduates in Hangzhou. However, there is still a considerable prevalence of thinness, it indicates a double burden of undernutrition and overnutrition.

Secular Change in Body Size and Somatotype of Indonesian Children aged 7–15 Years (1999–2019)

BACKGROUND: Secular changes assessment can help identifying the quality of health, wealth, and nutrition among populations and provide suggestions for policymakers. AIM: To examine the secular changes in weight, height, body mass index, and somatotype in Indonesian children between 1999 and 2019. METHODS: This cross-sectional study was conducted in 1999 and 2019 on 2021 children aged 7–15 years in Yogyakarta, Indonesia. Anthropometric measurements including height, weight, humerus and femur breadths, circumferences of upper arm and calf; skinfold thickness of triceps, subscapular, suprailiac, and calf were measured. Body mass index (BMI) was calculated as kg/m2. Somatotype components were defined by the Carter-Heath method. Statistical analyses used were three-ways ANOVA and least significant difference post hoc tests. RESULTS: Significant differences for boys and girls were found for height, weight, BMI, and three components of somatotype across the 2-time points. The boys in period 2019 were the tallest and girls were the heaviest, and for BMI, the highest value was observed in 2019 (girls). The children in the 1999 period had somatotype values 3.3 - 3.3 - 3.7 (boys) and 3.9 - 3.0 - 3.5 (girls), while in the 2019 period the somatotype values for boys were 3.5 - 4.5 - 3.0 and 4.3 - 4.1 - 2.4 for girls. CONCLUSION: In general, based on the order of age, there is a similar pattern between children in the two periods. Among Indonesian children from 1999 to 2019, there were positive trends in weight, BMI, endomorph, and mesomorph components, whereas a negative trend for the ectomorph component.

The Effect of Boarding on Obesity Among Middle School Students: Evidence From China

PURPOSE

This paper examines the effect of boarding on obesity among middle school students at boarding schools.

DESIGN

Quantitative, cross-sectional study.

SETTING

Data from the China Education Panel Survey (CEPS) were analyzed. The CEPS samples middle school students from 7th grade to 9th grade in China.

SUBJECTS

The final sample included 3,892 observations of boarding school students.

MEASURES

Measures included body mass index (BMI) that determined obesity, boarding status, demographic information, and instruments for boarding status.

ANALYSIS

The instrumental variables approach based on the 2 stage least squares (2SLS) methodology was utilized. The endogenous models and the extended probit models were also applied to the data to confirm the robustness of the results.

RESULTS

Boarding has a significant negative effect on obesity for middle school boys but a smaller negative effect on obesity for middle school girls. Boarding was estimated to reduce obesity by roughly 14% (p < 0.01) among middle school boys and 6% (p > 0.1) among middle school girls. The overall estimated effect based on the pooled sample was about 10% (p < 0.01).

CONCLUSION

School or government policies that encourage boarding at school can reduce obesity among middle school students, at least for middle school boys. Boarding at school can be a positive factor in preventing and controlling obesity among middle school students.

Childhood obesity in China: Does grandparents' coresidence matter?

Childhood obesity in China has been increasingly cited as a major public health issue in recent decades. The effect of grandparents on grandchildren's weight outcome is under-analyzed. Using data from the China Health and Nutrition Survey, we examine the effect of grandparents' coresidence on childhood weight outcome with a sample of 2-13-year-old children in China. We use instrumental variables to address the potential endogeneity of grandparents' coresidence. We show that the effect of grandparents' coresidence on childhood weight outcome is significantly positive. Grandparents' coresidence affects a grandchild's weight outcome through changes in dietary patterns and physical activity. The effects on dietary patterns exist in urban areas and significantly lower in rural areas. Grandparents' coresidence decreases physical activity more in rural areas than in urban areas. Furthermore, the effects of coresidence on protein intake and physical activities of children above 6 are significantly higher for males than females. A robustness check, including an ordered logit model with a body mass index category and estimation with additional data, validates our findings.

Spirometry reference values for population aged 7-80 years in China

BACKGROUND AND OBJECTIVE

Lung function tests are widely used in clinical and public health practice; however, no valid spirometry reference values were available for the general population in China. This study aimed to provide valid spirometry predictive equations for the general population in China, and to evaluate the predictive performance of previously used equations.

METHODS

Data from the China National Health Survey 2012-2015 and the 'Generalized Additive Models for Location, Scale and Shape' statistical modelling method were used to establish spirometry predictive equations for forced expiratory volume in 1 s (FEV₁ ), forced vital capacity (FVC) and FEV₁ /FVC. Paired t-tests were used to examine differences between spirometry measurements in this sample and predicted values of four previous spirometry predictive equations.

RESULTS

This study included 3130 lifetime non-smokers (713 males and 2417 females) aged 7-80 years in China. Spirometry predictive equations with age and height as predictive variables plus age-specific splines were established separately by gender. Most previous spirometry predictive equations were found to significantly overestimate (maximum of 3.69% in FEV₁ , 1.87% in FVC and 4.19% in FEV₁ /FVC for males; 11.46% in FEV₁ , 7.28% in FVC and 3.78% in FEV₁ /FVC for females) or underestimate (maximum of 5.75% in FEV₁ and 8.12% in FVC for males; 7.89% in FEV₁ and 9.32% in FVC for females) lung function measurements when applied to this sample population.

CONCLUSION

This study addressed the urgent need for valid and up-to-date spirometry reference values for the general population in China. Moreover, previous spirometry predictive equations showed unfavourable generalizability to this sample population.

Economics, human biology and inequality: A review of "puzzles" and recent contributions from a Deatonian perspective

The Nobel laureate Angus Deaton concentrated his work on puzzling developments and phenomena in economics. Puzzles are exciting elements in economics, because readers feel challenged by the question of how they can be solved. Among the puzzles analyzed by Deaton are: (1) Mortality increase of white, U.S. non-Hispanic men (2000 to today); (2) Why are height and income sometimes closely correlated, but not always?; (3) Height inequality among males and females; and (4) The Indian puzzle of declining consumption of calories during overall expenditure growth. This article reviews these "puzzles" and the main insights that Deaton derived from their discussion insofar as they pertain to the biological aspects of human development. I will focus on the field of this journal, Economics and Human Biology, in which Deaton has been very active over the last two decades. I will also document some of the responses by other scholars and their contributions to these puzzles, as they relate to the field of economics and human biology.

Do boys eat better than girls in India? Longitudinal evidence on dietary diversity and food consumption disparities among children and adolescents

This paper examines the dynamics of gender-based disparities in the intra-household allocation of food during childhood and adolescence in Andhra Pradesh and Telangana by using three rounds of longitudinal data from two cohorts. While boys are advantaged at all ages (except for the Younger Cohort at 12 years old), the pro-boy gap widens markedly at 15 years old. Specifically, mid-adolescent girls tend to consume fewer protein- and vitamin-rich foods such as eggs, legumes, root vegetables and fruit. This result is robust to gender differences between adolescents in terms of puberty onset, school enrolment, time use and dietary behaviours. Finally, gender disparities in dietary diversity during early and mid-adolescence do not vary by maternal education, poverty or place of residence, whilst they are moderated by levels of caregiver's educational aspirations at 15 years old.