Body mass index for children aged 6-18 years in Beijing, China

Growth charts for children aged 6-17 years in Shanxi, China: comparison with other cities of China and WHO

BACKGROUND

Growth charts are an important method for evaluating a child's health, growth, and nutritional status. It is essential to monitor the growth of children and adolescents using growth charts.

OBJECTIVES

To present body mass index (BMI)-for-age references reflecting children's growth in Shanxi. We also compare our new data with growth references of other cities of China and World Health Organization (WHO) growth standards.

METHODS

A stratified cluster random sampling method was used to recruit 5461 children and adolescents aged 6-17 years. Height and weight were measured and BMI was calculated. The LMS method was used to calculate the percentile values of body mass index by sex and age. Smoothed BMI-for-age growth curves were presented for both sexes and compared with reference data from other cities of China and WHO.

RESULTS

BMI centiles increased with age but with different patterns in both boys and girls. The centile curves from the 3rd to the 50th had a slight increase, while a sharp increase was seen from 11 to 17 years in boys and from 6 to 14 years in girls in the higher centiles. In comparison with other cities of China, the values for the 50th percentile are higher than those reported for children from China 2009, Shanghai, Changsha and China 2010 in both sexes. In comparison with WHO growth references, Chinese girls and boys had higher values in all percentiles, whereas curves of girls look roughly the same. The medians for BMI in Shanxi increase linearly from 6 to 17 years in boys.

CONCLUSIONS

The BMI percentiles of children aged 6-17 years in Shanxi differed significantly from the growth reference curves of other cities of China and WHO. Recommending the provision of BMI reference curves for local children and adolescents to assess their growth and development and monitor their nutritional status. Early detection of overweight and obesity in children provides a scientific basis for the prevention and control of overweight and obesity in children.

Reference growth curves to identify weight status (underweight, overweight or obesity) in children and adolescents: systematic review

The identification of somatic growth, through reference curves, can be used to create strategies and public policies to reduce public health problems such as malnutrition and obesity and to identify underweight, overweight and obesity. The purpose of this systematic review was to identify studies providing reference growth curves for weight status in children and adolescents. A systematic search was conducted in eight databases and in gray literature (Google scholar). To assess the risk of bias/methodological quality of studies, the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-sectional Studies (NHLBI) was used. Overall, 86 studies that met the inclusion criteria were included. Through the values   of reference growth curves for the identification of underweight, overweight and obesity, it was possible to verify that there is great variability among percentiles for the identification of underweight, overweight and obesity. The most prevalent percentiles for underweight were P3 and P5; for overweight, the most prevalent was P85 and the most prevalent percentiles for obesity were P95 and P97. The most prevalent anthropometric indicators were Body Mass Index (BMI), Waist Circumference (WC), Body Mass (BM) for age and height for age. Conclusion: Such data can demonstrate that the optimal growth must be reached, through the standard growth curves, but that the reference curves demonstrate a cut of the population growth, raising possible variables that can influence the optimal growth, such as an increase in the practice of physical activities and an awareness of proper nutrition.

Post-2000 growth trajectories in children aged 4-11 years: A review and quantitative analysis

Children's body mass index (BMI) growth trajectories are associated with adult health outcomes, and vary by geography and epoch. Understanding these trajectories could help to identify high risk children and thus support improved health outcomes. In this review, we compare and quantitatively analyse BMI level and trajectory data published since 2010. We characterise recent growth in children aged 4-11 years, an age range most frequently targeted for BMI intervention, yet less studied than young childhood or infancy. Through searches in OVID, we identified 54 relevant texts which describe either post-2000 summary BMI values by age and gender in cohorts with sample sizes of over 1000 children, or the results of latent class analyses of BMI trajectories within the 4-11 year age range. Population level median growth curves were projected and visualised as weighted means. These BMI curves, based on data from 729,692 children, can be visually clustered into 'high' and 'low' charting groups with extreme outlying values. Within populations, latent class analyses converge on 3-4 individual child trajectories, two of which predispose adult overweight. These growth pathways diverge early in childhood, yet are not effectively distinguished via isolated BMI measurements taken between 4 and 11 years, meaning some high risk children may currently be poorly identified.

An assessment of Body Mass Index and sensitive period for overweight development in Macao students at primary school age

The concomitant risk of physical inactivity and sedentary lifestyle development causing various non-communicable diseases is recognized worldwide. Therefore, development of strategies to form a concrete public health policy overcoming this problem is most important. This study observed the distribution and changes of Body Mass Index (BMI) over six years among boys and girls. Data on children height and weight and their BMI were collected. A total of 5369 (3368 male and 2001 female) children were recruited from 10 schools in Macao. The children were 6 years old in 2008 and turned 11 in 2013. Statistical analyses involved descriptive statistics, t-test, and a Chi-squared test. The findings indicated greater BMI among males than females across all age at the 0.05 level of significance, and the ages of 8 and 9 seemed to be a sensitive period for an increase in overweight and obesity. The results indicate the need to have focused strategies and structured interventions for males at the critical ages from 8 to 9 years.

Body Mass Index (BMI) assessment among Macau students: age group differences and weight management strategies

There is evidence that rapid weight gain during the first year of life is associated with being overweight later in life. Therefore, overweight tendencies need to be detected at an appropriate age, and suitable strategies need to be implemented for weight management to achieve optimal long-term health. The objective of this study was to investigate comparisons in BMI status and associated categories in male and female students over ten years in two phases, including 2008-2013 and 2009-2014. Weight and height data were collected to obtain BMI (Body Mass Index) over ten years in two phases. The first phase occurred from 2008 to 2013, and the second phase occurred from 2009 to 2014 in a population of 10846 school children (Males: 6970, 64.3%, and females: 3875, 35.7%) in Macau. Their ages ranged from 6 years old in 2008 to 11 years old in 2013. The same age range was observed in the second phase, i.e., 2009-2014. Statistical analyses included descriptive statistics, such as the mean, standard deviation, t-tests to determine gender differences (year-wise) and a Chi square test for independence to determine the relationship between BMI (Underweight, Standard, Overweight and Obese) and age groups. In the first phase (2008-2013), the findings indicated a higher BMI level among the male students than the female students across all age groups (2008 t = 5.24, 2009 t = 88.25, 2010 t = 11.32, 2011 t = 17.45, 2012 t = 19.70 and 2013 t = 19.92). In the second phase (2009-2014), a higher BMI level was found among the male students than the female students across all age groups (2009 t = 2.68, 2010 t = 2.886, 2011 t = 3.076, 2013 t = 4.228, and 2014 t = 2.405). The results of the two phases combined (2008 to 2014 and 2009 to 2014) revealed that male students in 2008 had a higher BMI level than their counterparts in 2009 in the two age categories (8 years t = 3.025 and 11 years t = 3.377). Female students in the second phase (2009-2014) showed a higher BMI level than their male counterparts (9 years, t = 3.151). The results indicate the need to have focused strategies and structured interventions for male students at the critical age range of 8 to 9 years old. The results of this study also imply the need for the delivery of suitable school intervention activities at the appropriate time. Specifically, the prevention of weight gain should start early in life to encourage the development of healthier behaviours and habits throughout childhood and later ages.

A policy-driven multifaceted approach for early childhood physical fitness promotion: impacts on body composition and physical fitness in young Chinese children

BACKGROUND

The prevalence of obesity increased while certain measures of physical fitness deteriorated in preschool children in China over the past decade. This study tested the effectiveness of a multifaceted intervention that integrated childcare center, families, and community to promote healthy growth and physical fitness in preschool Chinese children.

METHODS

This 12-month study was conducted using a quasi-experimental pretest/posttest design with comparison group. The participants were 357 children (mean age = 4.5 year) enrolled in three grade levels in two childcare centers in Beijing, China. The intervention included: 1) childcare center intervention (physical activity policy changes, teacher training, physical education curriculum and food services training), 2) family intervention (parent education, internet website for support, and family events), and 3) community intervention (playground renovation and community health promotion events). The study outcome measures included body composition (percent body fat, fat mass, and muscle mass), Body Mass Index (BMI) and BMI z-score and physical fitness scores in 20-meter agility run (20M-AR), broad jump for distance (BJ), timed 10-jumps, tennis ball throwing (TBT), sit and reach (SR), balance beam walk (BBW), 20-meter crawl (20M-C)), 30-meter sprint (30M-S)) from a norm referenced test. Measures of process evaluation included monitoring of children's physical activity (activity time and intensity) and food preparation records, and fidelity of intervention protocol implementation.

RESULTS

Children in the intervention center significantly lowered their body fat percent (-1.2%, p < 0.0001), fat mass (-0.55 kg, p <0.0001), and body weight (0.36 kg, p <0.02) and increased muscle mass (0.48 kg, p <0.0001), compared to children in the control center. They also improved all measures of physical fitness except timed 10-jumps (20M-AR: -0.74 seconds, p < 0.0001; BJ: 8.09 cm, p < 0.0001; TBT: 0.52 meters, p < 0.006; SR: 0.88 cm, p < 0.03; BBW: -2.02 seconds, p <0.0001; 30M-S: -0.45 seconds, p < 0.02; 20M-C: -3.36 seconds, p < 0.0001). Process evaluation data showed that the intervention protocol was implemented with high fidelity.

CONCLUSIONS

The study demonstrated that a policy-driven multi-faceted intervention can improve preschool children's body composition and physical fitness. Program efficacy should be tested in a randomized trial.

TRIAL REGISTRATION

ChiCTR-ONRC-14004143.