Changes in height, weight, BMI and in the prevalence of obesity among 9- to 11-year-old affluent Portuguese schoolboys, between 1960 and 2000

Changes in the Growth and Development of Adolescents in a Country in Socio-Economic Transition 1993-2013

Introduction

Changes in human growth and development depend on genetic and environmental factors. In the case of Slovenia, the environmental factors changed as a result of the period of socio-economic transition that the country underwent between 1991 and 2013. The authors used anthropometric techniques to evaluate differences in body height, proportions and sexual maturity in 1,221 adolescents aged 14 in 1993, 2003 and 2013.

Methods

Data was collected as a part of the ACDSi study, which has monitored children’s somatic growth and motor development every decade over the last 40 years.

Results

Between 1993 and 2013, a trend (p=0.08) towards increased body height was observed in males. The comparison of age at peak height velocity (PHV) between generations demonstrated a trend (p=0.07) of earlier entry into puberty in adolescents in 2013 compared to those in 1993. The leg-to-body height ratio increased (p<0.05) with every decade in males, while in females it decreased (p<0.05) in 2013. Similar trends were observed in the leg-to-trunk ratio. Contemporary generations experienced PHV at a younger age (p<0.05), which is true for both genders even in adolescents born no more than two decades (1993 (2013) apart. In both generations, females experienced PHV sooner than their male peers.

Conclusion

The authors assume that females of the 2013 generation reached puberty earlier than females of older generations. It is most likely that, unlike females from older generations and unlike males, they were already at the stage of trunk growth at the time of the measurements, which explains the observed changes in their trunk length, leg-to-body height and leg-to-trunk ratios in comparison to earlier generations.

Secular trends in weight, stature, and body mass index in Nova Scotia, Canada

OBJECTIVES

The present study aims to investigate the secular trends of weight, stature, and BMI values in a Nova Scotian sample from 1946 to 1999, with particular focus on how these trends may relate to nutrition and the evolving obesity epidemic.

METHODS

Data were collected from investigative (autopsy) records of 1645 individuals (1287 males, 358 females) of European descent at the Nova Scotia Medical Examiner Service. Secular trends were evaluated by linear regression of weight, stature, and BMI with respect to the year of birth. Further analysis of this sample was based on five time periods (birth cohorts), in order to determine whether dramatic shifts in diet and nutrition affected weight, stature, and BMI.

RESULTS

Overall, the results of this study demonstrate positive secular trends in weight, stature, and BMI from 1946 to 1999 in the Nova Scotian sample. Subsequent analysis among different time periods shows a secular increase in the weight of Nova Scotian males from 1946 to 1979, and a subsequent decrease in weight in after 1980. For Nova Scotian females, the results show a secular increase in weight from 1946 to 1989, and a subsequent decrease in weight after 1990. Such secular increases in weight coincide with the global nutrition transition, while recent decreasing median weight values may reflect economic growth and urbanization in Nova Scotia.

CONCLUSIONS

Overall, the results of the present study indicate that temporal trends in nutrition may have contributed to positive secular changes in weight, stature, and BMI in Nova Scotia, Canada between 1946 and 1999.

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

OBJECTIVES

To analyze the growth trends of children in Beijing from 1955 to 2010.

METHODS

Data for the period 1955-1975 were derived from published records. Data for the period 1985-2010 were derived from the Chinese National Survey on Students' Constitution and Health (CNSSCH). Since 1985, the overall sampling and measurement methods have been consistent. The mean, the standard deviation, and the variance (ANOVA) of height, weight, and BMI by age and sex of students aged 7-17 were calculated and analyzed.

RESULTS

Between 1955 and 2010, the average height and weight of children in Beijing has increased. The average increments per decade for boys and girls were 2.45cm and 2.03cm in height and 2.68kg and 1.68kg in weight, respectively. The largest height increase per decade occurred between 1975 and 1985: 4.51cm and 3.23cm for boys and girls, respectively. The largest height increase for the entire 55-year period under study occurred among boys at age 13 (17.85cm) and among girls at age 11 (15.90cm.)

CONCLUSIONS

During the period 1955-2010, growth trends among children in Beijing were positive. The health and nutritional status of these children improved significantly. Since 2007, might be related to government intervention, childhood obesity has been curbed.

Gender, weight status and socioeconomic differences in psychosocial correlates of physical activity in schoolchildren

OBJECTIVES

This study sought to assess differences in attraction to physical activity, perceived physical competence and parental socialization influences across gender, body mass index and socioeconomic status in Portuguese children.

DESIGN

Cross-sectional study.

METHODS

683 children, aged 8-10 years, from elementary schools were participants. Attraction to physical activity, perceived physical competence, parental socialization influences and socioeconomic status were assessed via standardized questionnaires. The prevalence of overweight and obesity was calculated using body mass index, based on the international cut-off points. MANOVA and ANOVA models were conducted.

RESULTS

Boys reported greater enjoyment of games and sports participation than did girls. Boys and normal-weight children perceived themselves as being more successful and physically competent than did girls and obese children. Normal-weight girls enjoyed participation in vigorous physical activity more than did overweight and obese girls. Obese children felt less accepted by their peers in games and sports than did normal-weight and overweight children. High and medium socioeconomic status children perceived physical activity participation as of greater importance than did low-socioeconomic status children. High-socioeconomic status girls reported greater liking of the exertional aspects of physical activity compared to low socioeconomic status girls. High socioeconomic status children were more likely to perceive their parents as positive role models and perceived that they had greater enjoyment of physical activity than did lower socioeconomic status children.

CONCLUSIONS

These results suggest that physical activity promotion interventions should focus on girls, obese children and lower socioeconomic status children as these individuals tend to have lower levels of attraction to physical activity, lower perceived physical competence and less parent physical activity support, which puts them at greater risk of being physically inactive.

Growth and obesity in 7-year-old Croatian children: secular changes from 1991 to 2008

The study analyses secular changes in body weight, height and body mass index (BMI) in children in the Splitsko-dalmatinska County, Croatia, in the period from 1991 to 2008. The overweight/obesity trends from 1991 to 1999 and from 2000 to 2008 are assessed. The study included three cohorts of healthy 7-year-old children, measured during their regular medical examination before enrolment at school: 1991 (n = 514), 1999 (n = 428) and 2008 (n = 452), in a total of 1,394 children, 686 (49.21%) of whom were girls. Overweight/obesity was defined according to the International Obesity Task Force criteria. From 1991 to 2008, there was a statistically significant rise in body weight and BMI in boys and girls (1.47 vs 1.50 kg; 0.55 vs 0.75 kg) and height in boys (1.4 cm). In 2008, the girls were 0.14 kg heavier and 0.39 cm taller than the girls of the same age measured in 1999, but their BMI was lower by 0.02 units. The frequency of obesity rose from 1991 to 2008 by 1.4 times in boys and 1.7 times in girls. The prevalence of obesity in girls rose from 1991 to 1999 (from 4.3% to 8.6%), but in 2008, it fell (7.1%). The prevalence of obesity in boys fell in 1999 (from 4.3% to 3.9%) but rose in 2008 (6.2%). The values of body weight, height and BMI in the observed population moved from 1991 to 2008 towards higher WHO standard values, which is descriptive of the problem of obesity and supports the need to consider the choice of cut-off points for obesity/overweight in local and national studies. In conclusion, the slowdown noticed in secular changes in body weight and BMI is encouraging and shows the importance of continuous paediatric health care for children, combined with an altered attitude in society towards obesity in children.

Availability of data assessing the prevalence and trends of overweight and obesity among European adolescents

OBJECTIVE

To review recent data on objectively measured overweight/obesity in national representative samples of European adolescents (aged 10-18 years), as well as availability of studies assessing trends in overweight/obesity in this target group. Attention was paid to the ability of the data to describe the obesity epidemic, especially in sociodemographic subgroups.

DESIGN/SETTING/SUBJECTS

Data on prevalence and trends in overweight/obesity among adolescents in the twenty-seven European Community member states, Iceland, Norway and Switzerland, available as scientific publications as well as reports or unpublished data by the end of 2009, were retrieved. Reports on the most recent objectively measured data from national representative samples were selected and described with regard to the years of data collection, sample sizes, response rates, age ranges included, trends by age, type of measures of overweight/obesity, sociodemographic variables and the sources of information.

RESULTS

Objectively measured data on national representative samples were identified for only half of the countries, and the trend studies were mainly conducted applying subnational samples. Most studies used the criteria from the International Obesity Task Force (IOTF) to define overweight/obesity, but the age ranges studied and the years of data collection varied, and information on sample sizes and response rates were often not presented. Data on trends of overweight/obesity over time are increasing, and the most recent studies indicate that the prevalence rate of overweight/obesity has stabilized. Few studies reported data by sociodemographic subgroups other than gender and age.

CONCLUSIONS

Objectively measured data on national representative samples of adolescents appear scattered, and there is a large heterogeneity with respect to the quality and comparability of available data. Increasing use of the IOTF criteria for overweight/obesity contributes to improved comparability across studies. Data by sociodemographic subgroups, and in particular by socio-economic status, are scarce.