Prevalence and sociodemographic determinants of overweight in young French adolescents

Gender differences and climate zones in overweight and obesity prevalence in European elementary school children from 2000 to 2020: a systematic review and meta-analysis

Introduction

After 2000, there are more obese than underweight people in the world. We face a rapid increase in average global warming of 1.5°C, reported as a syndemic problem of three interconnected epidemics: obesity, global warming, and undernutrition. We aimed to analyze the impact and association between global warming and obesity in children and differences by gender across Europe after 2000.

Methods

We searched PubMed, MEDLINE, Google Scholar, ScienceDirect, and Embase databases. The considered population were children aged 6-14. Only cross-sectional studies that defined obesity by the IOTF cutoffs and the subjects' place of residence, used to determine precise climate zones, were included. We assessed the prevalence of obesity and overweight using a random-effects and the Mantel-Haenszel fixed-effect method when heterogeneity was greater/lower than 50%. We did a subgroup analysis for prevalence across gender, obesity, and overweight, two decades, regions, countries, and the Köppen-Geiger climate zones. Random effects of the meta-regression were used to study the global warming impact and differences in trends across European countries by gender for both conditions separately.

Results

We identified 114 studies that included 985,971 children from 39 European countries. A significant difference between genders was in favor of obese girls 4.78 (95% CI: 3.85-5.93) versus boys 5.76% (95% CI: 5.11-6.48, p = 0.03), respectively, but not for overweight children. Most of the obese girls were in South Europe 7.51% (95% CI: 6.61-8.51) versus East Europe 2.86% (95% CI: 23-3.12), versus boys in South Europe 8.66% (95% CI: 7.68-9.74) and North Europe 3.49% (95% CI: 2.90-4.19), respectively. The "cold" Köppen-Geiger climate zone, with lowest temperatures, has the largest trend rise between two decades of 2.8% and 1.53% for obese girls and boys, and 5.31% and 1.81% for overweight girls and boys, respectively, followed by the smallest number of obese girls 3.28% (95% CI: 2.17-4.92) and boys 3.58% (95% CI: 2.39-5.33), versus the zone with the highest temperatures "hot" for girls 7.02% (95% CI: 6.30-7.82) and for boys 8.23% (95% CI: 7.55-8.96), respectively. The meta-regression proved global warming has a significant impact on the distribution of obesity and overweight across climate zones, R2 = 0.52 and R2 = 0.22. No significant gender differences, or significant interaction, was noted.

Conclusion

Our meta-analysis provides a comprehensive overview of the association between and impact of global warming on obesity. This impact increases obesity among children in Europe throughout all climate zones, and emphasizes an urgent call for further preventive methods in schools, since obesity differences continue their trend of disappearing into the future.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021282127, identifier: CRD42021282127.

Effects of a Smartphone App on Fruit and Vegetable Consumption Among Saudi Adolescents: Randomized Controlled Trial

BACKGROUND

Dietary patterns and nutritional status during adolescence have a direct effect on future health outcomes.

OBJECTIVE

This study aimed to promote fruit and vegetable intake among adolescents using a smartphone app called MyPlate.

METHODS

This randomized intervention study was conducted in an urban area of Jeddah, Saudi Arabia. We included 104 adolescents aged 13 to 18 years, who were randomized into intervention (n=55) or control (n=49) arms. We examined the effects of MyPlate on fruit and vegetable intake over 6 weeks in the intervention group. Pre- and postintervention questionnaires were used in the intervention and control groups.

RESULTS

The control group showed a significant increase in fruit consumption scores between baseline (1.15, SD 0.68) and postintervention (1.64, SD 0.98; P=.01), but no significant difference in vegetable consumption scores was observed before (1.44, SD 0.97) and after intervention (1.55, SD 0.90; P=.54). However, there was no significant difference between scores at baseline and after 6 weeks of using the smartphone app for fruit (1.48, SD 0.99 and 1.70, SD 1.11, respectively; P=.31) or vegetables (1.50, SD 0.97 and 1.43, SD 1.03, respectively; P=.30) in the intervention group. Our findings showed no significant impact of using a smartphone app on fruit and vegetable consumption.

CONCLUSIONS

These findings suggest that a smartphone app did not significantly improve fruit and vegetable intake among adolescents.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05692765; https://clinicaltrials.gov/ct2/show/NCT05692765.

Family socioeconomic status and childhood adiposity in Europe - A scoping review

Childhood obesity is a considerable public health problem worldwide. In Europe, lower parental socioeconomic status (SES) relates to higher childhood adiposity. This scoping review strives to discover, which SES indicators are the most commonly used and meaningful determinants of childhood adiposity (greater level of continuous adiposity indicator, e.g. body mass index z-score, or overweight or obesity categorized by established definitions). The review focused on studies about European general populations from the 21st century (January 2000-April 2021) considering children and adolescents aged 0-17 years. PubMed and reference lists of articles were searched in February-April 2021. Total of 53 studies with 121 association analyses between different SES indicators and adiposity indicators, were identified and reviewed. Different SES indicators were grouped to 25 indicators and further to six indicator groups. The most used indicator was mother's education (n of association analyses = 24) and the most used indicator group was parental education (n of association analyses = 51). Of all association analyses, 55% were inverse, 36% were non-significant, and 8% were positive. Composite SES (80%), parental education (69%) and parental occupation (64%) indicators showed most frequently inverse associations with obesity measures (i.e. lower parental SES associating with higher adiposity), while parental income (50% inverse; 50% non-significant) and property and affluence (42% inverse; 50% nonsignificant) indicators showed approximately even number of inverse and non-significant associations. Instead, majority of parental employment (60%) indicators, showed non-significant associations and 33% showed positive associations (i.e. higher parental SES associating with higher adiposity). Despite some variation in percentages, majority of the associations were inverse in each age group and with different outcome categorizations. In girls and in boys, non-significant associations predominated. It seems that children with parents of higher SES have lower likelihood of adiposity in Europe. Parents' employment appears to differ from other SES indicators, so that having an employed parent(s) does not associate with lower likelihood of adiposity. Positive associations seem to occur more frequently in poorer countries. Criteria for uniform childhood SES and adiposity measures should be established and used in studies in order to be able to produce comparable results across countries.

French youth trends in prevalence of overweight, obesity and underweight from 2008 to 2018

Objective

Because the prevalence overweight and obesity remains high during adolescence in Europe, tracking weight status in children and adolescents is needed. We aimed to estimate French trends in the prevalence of weight status in children and adolescent from 2008 to 2018.

Results

The prevalence of overweight and obesity were higher in boys (P < 0.0001). Underweight was more prevalent in girls (P < 0.0001). In adolescents aged 16–17 years old, a stabilization was observed for overweight and obesity whereas the prevalence of underweight increased significantly in boys (P < 0.0001). For children and adolescents aged to 10–12 and 13–15 years old, the obesity and overweight decreased significantly while the underweight was increased for both sexes aged 10–12 years (P < 0.0001). Underweight increased in boys aged 13–15 years (P < 0.0001) while that a stagnation was observed in girls. These encouraging results show the permanent need to develop preventive strategies promoting an healthy active living in order to modify the lifestyle for adolescents with underweight, overweight or obesity.

Use of Machine Learning to Determine the Information Value of a BMI Screening Program

INTRODUCTION

Childhood obesity continues to be a significant public health issue in the U.S. and is associated with short- and long-term adverse health outcomes. A number of states have implemented school-based BMI screening programs. However, these programs have been criticized for not being effective in improving students' BMI or reducing childhood obesity. One potential benefit, however, of screening programs is the identification of younger children at risk of obesity as they age.

METHODS

This study used a unique panel data set from the BMI screening program for public school children in the state of Arkansas collected from 2003 to 2004 through the 2018-2019 academic years and analyzed in 2020. Machine learning algorithms were applied to understand the informational value of BMI screening. Specifically, this study evaluated the importance of BMI information during kindergarten to the accurate prediction of childhood obesity by the 4th grade.

RESULTS

Kindergarten BMI z-score is the most important predictor of obesity by the 4th grade and is much more important to prediction than sociodemographic and socioeconomic variables that would otherwise be available to policymakers in the absence of the screening program. Including the kindergarten BMI z-score of students in the model meaningfully increases the accuracy of the prediction.

CONCLUSIONS

Data from the Arkansas BMI screening program greatly improve the ability to identify children at greatest risk of future obesity to the extent that better prediction can be translated into more effective policy and better health outcomes. This is a heretofore unexamined benefit of school-based BMI screening.

A cross-sectional association of physical fitness with positive and negative affect in children and adolescents: the up & down study

BACKGROUND

Affect and physical fitness play an important role in psychological and physical health; however, the association between those variables in youth remains unknown. The aim of the present study was to examine the influence of physical fitness on positive and negative affect in Spanish children and adolescents.

METHOD

Healthy young Spanish people (n = 1,490) were recruited for the present study: 542 children (n = 272 girls; mean age 9.6 years) and 948 adolescents (n = 454 girls; mean age 14.1 years) with complete baseline data on health-related fitness tests (20 m shuttle run test, 4 × 10 m test, muscular fitness index, and physical fitness index), and positive and negative affect (Positive and Negative Affect Schedule).

RESULTS

Higher performance on physical fitness components was associated with positive affect (β = -0.176-0.118, all P < 0.05). There was no association between all physical fitness components and negative affect (β = -0.100-0.15, all P > 0.05). There were differences on positive affect between the lowest and the highest quartile of the physical fitness index in boys (P = 0.037, Cohen's d 0.60) and girls (P = 0.004, Cohen's d = 0.69), and between the lowest and the highest quartile of muscular fitness index in girls (P < 0.001, Cohen's d = 0.76).

CONCLUSIONS

Promoting physical activity during the school years, including strength exercises to increase muscular fitness, could improve positive affect levels and thus psychological health.

Overweight and Obesity in Italian Adolescents: Examined Prevalence and Socio-Demographic Factors

AIM

This study aimed to evaluate the prevalence of overweight and obesity derived from measured data of weight and height in a cross-sectional sample of adolescents in the Italian region of Lazio and to analyse their association with different socio-demographic factors.

METHODS

The study was conducted in a representative sample of 15-16-year-old adolescents recruited in secondary schools between December 2011 and May 2012. 369 adolescents were investigated. Body weight, height and waist circumference were measured. The BMI of each subject was calculated, and the prevalence of overweight and obesity was determined by age and sex using the IOTF reference values and WHO growth standards. Waist circumference/height ratio (WC/Ht) was calculated and the subjects were classified using the cut-off of 0.5: WC/Ht≥0.5 and WC/Ht<0.5. Selected socio-demographic characteristics were assessed via questionnaire.

RESULTS

The percentages of overweight and obesity were high, 15.4% and 7.9%, respectively, with significant difference between males and females (19.1% vs. 12.6% for overweight and 11.1% vs. 5.3% for obese) using the IOFT reference. The ratio WC/Ht≥0.5 was observed in 12.7% of the sample (all the obese and 29.8% of the overweight subjects). Multiple logistic regression analysis indicated that gender, school municipality, mother's employment status, and family structure had a significant effect on ponderal status (overweight/obesity vs. normal weight).

CONCLUSION

These findings show a high prevalence of body weight excess associated with socio-demographic factors in the Italian sample investigated, and the need for effective public health interventions to combact obesity with particular attention to disadvantaged adolescents.

Prevalence of overweight, obesity, underweight and normal weight in French youth from 2009 to 2013

OBJECTIVE

To determine the prevalence of underweight, overweight and obesity in French youth from 2009 to 2013 and to determine if there are differences in weight categories according to socio-economic status.

DESIGN

Cross-sectional study performed in different regions of France. Physical measures included weight, height and BMI. Underweight, overweight and obesity were defined according to age- and sex-specific BMI cut-off points from the International Obesity Task Force.

SETTING

France.

SUBJECTS

Children and adolescents (n 9670; 4836 boys, 4834 girls) from the French national BOUGE Program between 2009 and 2013.

RESULTS

The prevalence of obesity was higher in boys than girls (P0·05) and remained unchanged in boys (7·1-7·3 %) between 2009 and 2013. Overweight and obesity were higher in low socio-economic families (P<0·0001).

CONCLUSIONS

Findings suggest that the prevalence of overweight was stable although high in French children and adolescents, while the prevalence of obesity increased significantly. Changes in underweight, although not significant, were high in girls and merit further attention. Improving public health interventions, especially in high-risk low socio-economic populations, may help to modify the behaviour that contributes to underweight, overweight and obesity in young boys and girls.

Parents' education and child body weight in France: The trajectory of the gradient in the early years

This paper explores the relationship between parental education and offspring body weight in France. Using two large datasets spanning the 1991-2010 period, we examine the existence of inequalities in maternal and paternal education and reported child body weight measures, as well as their evolution across childhood. Our empirical specification is flexible and allows this evolution to be non-monotonic. Significant inequalities are observed for both parents' education--maternal (respectively paternal) high education is associated with a 7.20 (resp. 7.10) percentage points decrease in the probability that the child is reported to be overweight or obese, on average for children of all ages. The gradient with respect to parents' education follows an inverted U-shape across childhood, meaning that the association between parental education and child body weight widens from birth to age 8, and narrows afterward. Specifically, maternal high education is correlated with a 5.30 percentage points decrease in the probability that the child is reported to be overweight or obese at age 2, but a 9.62 percentage points decrease at age 8, and a 1.25 percentage point decrease at age 17. The figures for paternal high education are respectively 5.87, 9.11, and 4.52. This pattern seems robust, since it is found in the two datasets, when alternative variables for parental education and reported child body weight are employed, and when controls for potential confounding factors are included. The findings for the trajectory of the income gradient corroborate those of the education gradient. The results may be explained by an equalization in actual body weight across socioeconomic groups during youth, or by changes in reporting styles of height and weight.

Socioeconomic position and childhood-adolescent weight status in rich countries: a systematic review, 1990-2013

Background

Childhood obesity is a major problem in rich countries due to its high prevalence and its harmful health consequences. An exploratory analysis conducted in the PubMed database highlighted that the number of papers published on the relationship between socioeconomic position (SEP) and childhood-adolescent weight status had risen substantially with respect to an earlier review which had covered the period 1990–2005.

Methods

To describe the findings on the relationship between SEP and childhood-adolescent weight status in papers published in rich countries from 1990 through 2013, studies were identified in the following databases: PubMed; Web of Knowledge (WOK); PsycINFO; Global Health; and Embase. We included observational studies from the 27 richest OECD countries, which covered study populations aged 0 to 21 years, and used parental education, income and/or occupation as family SEP indicators. A total of 158 papers met the inclusion criteria and reported 134 bivariable and 90 multivariable analyses.

Results

Examination of the results yielded by the bivariable analyses showed that 60.4 % of studies found an inverse relationship, 18.7 % of studies did not found relationship, and 20.9 % of studies found a relationship that varied depending on another variable, such as age, sex or ethnic group; the corresponding percentages in the multivariable analyses were 51.1, 20.0 and 27.8 %, respectively. Furthermore, 1.1 % found a positive relationship.

Conclusion

The relationship between SEP and childhood-adolescent weight status in rich countries is predominantly inverse and the positive relationship almost has disappeared. The SEP indicator that yields the highest proportion of inverse relationships is parents’ education. The proportion of inverse relationships is higher when the weight status is reported by parents instead using objective measurements.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0443-3) contains supplementary material, which is available to authorized users.

Objectively measured and self-reported leisure-time sedentary behavior and academic performance in youth: The UP&DOWN Study

OBJECTIVE

To examine the associations of (i) objectively measured and self-reported sedentary behavior during leisure time with academic performance and (ii) patterns of sedentary behavior with academic performance.

METHODS

This study was conducted with 1146 youth aged 12.5±2.5years in Spain during 2011-2012. Leisure-time sedentary behavior during out-of-school hours was assessed by accelerometry and self-report. Academic performance was assessed through school grades.

RESULTS

Objectively measured sedentary leisure-time was not significantly associated with academic performance. Time spent in Internet surfing, listening to music, and sitting without doing anything were negatively associated with all academic performance indicators (β ranging from -0.066 to -0.144; all p<0.05). However, time spent in doing homework/study without computer and reading for fun were positively associated (β ranging from 0.058 to 0.154; all p<0.05). Five major sedentary patterns were identified. The "high social-low TV/video" and the "low studying-high TV/video" patterns were negatively associated with all academic indicators (β ranging from -0.085 to -0.148; all p<0.05). The "educational" pattern was positively associated with all academic indicators (β ranging from 0.063 to 0.105; all p<0.05).

CONCLUSIONS

Specific domains of self-reported sedentary behavior during leisure-time, but not objectively measured sedentary leisure time, may influence academic performance.

FACTORS ASSOCIATED WITH CHILDREN'S HEIGHT AND BODY MASS INDEX IN LITHUANIA, 1990-2008

The aim of the study was to reveal the ethnic and socioeconomic factors associated with height and body mass index (BMI) of children during the period of political and social transition in Lithuania in 1990-2008. Data were derived from the personal health records of 1491 children (762 boys and 729 girls) born in 1990 in Vilnius city and region. Height and BMI from birth up to the age of 18 years were investigated. Children were divided into groups according to their ethnicity, place of residence, father's and mother's occupation and birth order. Height and BMI were compared between the groups; a Bonferroni correction was applied. A multiple linear regression model was used to measure the effects of the independent variables on height and BMI. Girls living in Vilnius city were significantly taller in later life at the ages of 8 and 11 years. Sons of mothers employed as office workers appeared to be significantly taller at the ages of 7, 12, 14 and 15 years compared with the sons of labourers. First-born girls were taller at the age of 7 years than later-born girls of the same age (124.48±5.11 cm and 122.92±5.14 cm, respectively, p<0.001). Later-born children of both sexes had higher BMIs at birth compared with first-borns; however, first-born girls had higher BMIs at the age of 11 years compared with their later-born peers (17.78±2.87 kg/m² and 16.79±2.14 kg/m² respectively, p<0.001). In the multiple linear regression model, the five tested independent variables explained only up to 18% of total variability. Boys were more sensitive to ethnic and socioeconomic factors: ethnicity appeared to be a significant predictor of boys' height at the age of 5 years (p<0.001), while birth order (p<0.001) predicted boys' BMI at birth. In general, ethnicity, place of residence, father's and mother's occupation and birth order were not associated with children's height and BMI in most age groups.

Maternal physical activity before and during the prenatal period and the offspring's academic performance in youth. The UP&DOWN study

OBJECTIVE

To examine the association of maternal physical activity before and during pregnancy with academic performance in youth.

METHODS

This study included 1868 youth (6-18 years) and their mothers. Mothers recalled their physical activity before and during pregnancy. Mothers were categorized into four groups: "remained active", "became inactive", "became active" and "remained inactive". Academic performance was assessed through school records.

RESULTS

Boys whose mothers practiced physical activity before or during pregnancy had significantly higher scores in academic performance indicators independently of physical activity, fitness, current body mass index (BMI) and birthweight than those whose mothers did not practice physical activity before or during pregnancy (all p < 0.05). In addition, boys whose mothers remained active had higher scores in all academic indicators (ranging from +0.358 to +0.543) than boys whose mothers remained inactive. Boys whose mothers remained active had higher scores in Language (score +0.546; 95% CI, 0.150-0.940), average of Math and Language (score +0.468; 95% CI, 0.100-0.836) and grade point average (GPA) (score +0.368; 95% CI, 0.092-0.644) than boys whose mothers became active.

CONCLUSIONS

Maternal physical activity before and during pregnancy may positively influence youth's academic performance. Continuing maternal physical activity practice during pregnancy may have greater benefits for youth's academic performance.

Socio-economic position as an intervention against overweight and obesity in children: a systematic review and meta-analysis

Studies that investigated the association between socio-economic position (SEP) and obesity in children suggest inconsistent results. The aim of this study is to summarize and quantify the current evidence on SEP and risks of overweight and obesity in children aged 0–15 years. Relevant studies published between 1990 to Sep 4, 2014 were searched in Medline, Web of Science, Embase, and the Cochrane Database of Systematic Reviews. Risk estimates from individual studies were pooled using random-effects models, according to lowest vs the highest SEP category. A total of 62 articles were included in the meta-analysis. The odds of both overweight risk and obesity risk were higher in the children with lowest SEP than in those with highest SEP (OR, 1.10, 95% CI: 1.03–1.17, and OR, 1.41, 95% CI: 1.29–1.55, respectively). Sub-group analyses showed that the inverse relationships between SEP and childhood overweight and obesity were only found in high-income countries and in more economic developed areas. In conclusion, our study suggests that children with lower SEP had higher risks of overweight and obesity, and the increased risks were independent of the income levels of countries.

Independent and combined influence of neonatal and current body composition on academic performance in youth: The UP & DOWN Study

BACKGROUNDS

Unhealthy body composition is a cause for concern across the lifespan.

OBJECTIVE

The objective of this study was to examine the independent and combined associations between neonatal and current body composition with academic performance among youth.

METHODS

This cross-sectional study was conducted with a total of 1557 youth (745 girls) aged 10.4 ± 3.4 years. Birth weight and length at birth were self-reported. Current body composition was assessed by body mass index (BMI), waist circumference (WC) and percentage of body fat (BF%). Academic performance was assessed through schools records.

RESULTS

Birth weight was related to all academic variables in boys, independent of potential confounders, including BMI; whereas WC, BMI and BF% were related to all academic performance indicators in both boys and girls, independent of potential confounders, including birth weight (all P < 0.05). In addition, the combined adverse effects of low birth weight and current overweight on academic performance were observed in both boys and girls for grade point average (GPA) indicator. Boys in the group with none adverse effect had significantly higher scores in GPA (score +0.535; 95% confidence interval, 0.082-0.989) than boys in the group of both adverse effects (P < 0.007); among girls, GPA score was higher in the group with none adverse effect than in the groups with one or two adverse effects (P for trend = 0.029).

CONCLUSIONS

Neonatal and current body composition, both independently and combined, may influence academic performance in youth.

Objectively measured physical activity has a negative but weak association with academic performance in children and adolescents

AIM

There is an emerging body of evidence on the potential effects of regular physical activity on academic performance. The aim of this study was to add to the debate, by examining the association between objectively measured physical activity and academic performance in a relatively large sample of children and adolescents.

METHODS

The Spanish UP & DOWN study is a 3-year longitudinal study designed to assess the impact, overtime, of physical activity and sedentary behaviours on health indicators. This present analysis was conducted with 1778 children and adolescents aged 6-18 years. Physical activity was objectively measured by accelerometry. Academic performance was assessed using school grades.

RESULTS

Physical activity was inversely associated with all academic performance indicators after adjustment for potential confounders, including neonatal variables, fatness and fitness (all p < 0.05). This association became nonsignificant among quartiles of physical activity. There were only slight differences in academic performance between the lowest and the second quartile of physical activity, compared to the highest quartile, with very small effect size (d < 0.20).

CONCLUSION

Objectively measured physical activity may influence academic performance during both childhood and adolescence, but this association was negative and very weak. Longitudinal and intervention studies are necessary to further our understanding.

Danish children born to parents with lower levels of education are more likely to become overweight

AIM

Little is known about whether the socio-economic status of parents is linked to their children becoming overweight. This study examined the association between parents' educational level and overweight Danish children in a nationally representative sample.

METHODS

Body mass index was calculated for a random sample of 512 children aged from four to 14 from the Danish National Survey of Diet and Physical Activity 2005-2008. Their parents provided weight and height data during an interview, together with details of their own educational level. Children were classified as overweight/obese in accordance with the International Obesity Task Force. Frequency estimates of prevalence and logistic regression models were used to correlate childhood overweight/obesity with the mothers' and fathers' educational levels as the main outcome measures.

RESULTS

Danish mothers tended to be more highly educated than fathers and their educational level was inversely associated with their child being overweight, especially if it was a boy. However, the highest educational level of the parents was the only significant educational variable, suggesting that education was associated with overweight children irrespective of the gender of the parent.

CONCLUSION

Public health initiatives should target parents with low educational levels to prevent, and reduce, social inequality in overweight children.

Independent and combined influence of the components of physical fitness on academic performance in youth

OBJECTIVE

To examine the independent and combined associations of the components of physical fitness with academic performance among youths.

STUDY DESIGN

This cross-sectional study included a total of 2038 youths (989 girls) aged 6-18 years. Cardiorespiratory capacity was measured using the 20-m shuttle run test. Motor ability was assessed with the 4×10-m shuttle run test of speed of movement, agility, and coordination. A muscular strength z-score was computed based on handgrip strength and standing long jump distance. Academic performance was assessed through school records using 4 indicators: Mathematics, Language, an average of Mathematics and Language, and grade point average score.

RESULTS

Cardiorespiratory capacity and motor ability were independently associated with all academic variables in youth, even after adjustment for fitness and fatness indicators (all P≤.001), whereas muscular strength was not associated with academic performance independent of the other 2 physical fitness components. In addition, the combined adverse effects of low cardiorespiratory capacity and motor ability on academic performance were observed across the risk groups (P for trend<.001).

CONCLUSION

Cardiorespiratory capacity and motor ability, both independently and combined, may have a beneficial influence on academic performance in youth.

Gut microbioma population: an indicator really sensible to any change in age, diet, metabolic syndrome, and life-style

Obesity has become a pandemic threat in the latest 30 years. The trend of the prevalence of overweight and obesity has got an overall increase in every part of the world, regardless of ethnicity, life-style and social ties. High food intake, genetic, and sedentary have been related to obesity; it has been also hypothesized that gut microbiota could have an impact on the complex mechanism underlying the weight gain. This review aims to illustrate the actual literature about gut microbiota and its relation with obesity and to analyze the possible implications of factors such as diet and life-style onto the composition of gut microbiota, that can lead to overweight/obesity condition.

Evolution of overweight prevalence among 5-6-year-old children according to socio-economic status

AIM

To assess time trends in overweight and obesity prevalence among 5-6-year-old children of Bordeaux city (France) over seven school years from 2004-2005 to 2010-2011.

METHODS

For each year, all 5-6-year-old children from 63 of the 69 schools of Bordeaux were included: 2005, 2100, 2010, 1952, 2040, 2017 and 2111 subjects, respectively. Weight and height were collected by school doctors, and weight status was defined according to the age- and sex-specific body mass index cut-off points of the International Obesity Task Force (IOTF) for obesity and to the French age- and gender-specific child cut-off (close to the IOTF cut-off) for overweight including obesity.

RESULTS

From 2004-2005 to 2010-2011, an overall decrease was observed in overweight including obesity (from 8.9% to 5.2%, p < 0.001) and obesity prevalences (from 2.8% to 1.4%, p = 0.046). Similar results were observed in non-low socio-economic status (SES) areas (p < 0.001), whereas the prevalence did not vary significantly in low-SES areas (p > 0.05).

CONCLUSION

Overweight prevalence has decreased between 2004 and 2011 in 5-6-year-old children from Bordeaux. However, the gap between low and non-low-SES areas has persisted during these years.

Dietary arginine and linear growth: the Copenhagen School Child Intervention Study

The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001–2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2·5–2·8 and 2·8–3·2 g/d, respectively) compared with the first quintile ( < 2·2 g/d) (P for trend = 0·04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0·14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.

Longitudinal association between marital disruption and child BMI and obesity

This research examines whether family disruptions (i.e., divorces and separation) contribute to children's weight problems. The sample consists of 7,299 observations for 2,333 children, aged 5-14, over the 1986-2006 period, from a US representative sample from the Child and Young Adult Survey accompanying the National Longitudinal Survey of Youth (NLSY). The study uses individual-fixed-effects models in a longitudinal framework to compare children's BMI and weight problems before and after a disruption. Furthermore, besides doing a before-after comparison for children, the study also estimates the effects at various periods relative to the disruption in order to examine whether children are affected before the disruption and whether any effects change as time passes from the disruption, as some effects may be temporary or slow to develop. Despite having a larger sample than the previous studies, the results provide no evidence that, on average, children's BMI and BMI percentile scores (measured with continuous outcomes) are affected before the disruption, after the disruption, and as time passes from the disruption, relative to a baseline period a few years before the disruption. However, children experiencing a family disruption do have an increased risk of obesity (having a BMI percentile score of 95 or higher) in the two years leading up to the disruption as well as after the disruption, and as time passes from the disruption.

Spatial accessibility to physical activity facilities and to food outlets and overweight in French youth

Objective:

Some characteristics of the built environment have been associated with obesity in youth. Our aim was to determine whether individual and environmental socio-economic characteristics modulate the relation between youth overweight and spatial accessibility to physical activity (PA) facilities and to food outlets.

Design:

Cross-sectional study.

Subjects:

3293 students, aged 12±0.6 years, randomly selected from eastern France middle schools.

Measurements and methods:

Using geographical information systems (GIS), spatial accessibility to PA facilities (urban and nature) was assessed using the distance to PA facilities at the municipality level; spatial accessibility to food outlets (general food outlets, bakeries and fast-food outlets) was calculated at individual level using the student home address and the food outlets addresses. Relations of weight status with spatial accessibility to PA facilities and to food outlets were analysed using mixed logistic models, testing potential direct and interaction effects of individual and environmental socio-economic characteristics.

Results:

Individual socio-economic status modulated the relation between spatial accessibility to PA facilities and to general food outlets and overweight. The likelihood of being overweight was higher when spatial accessibility to urban PA facilities and to general food outlets was low, but in children of blue-collar-workers only. The odds ratio (OR) (95% confidence interval) for being overweight of blue-collar-workers children compared with non-blue-collar-workers children was 1.76 (1.25–2.49) when spatial accessibility to urban PA facilities was low. This OR was 1.86 (1.20–2.86) when spatial accessibility to general food outlets was low. There was no significant relationship of overweight with either nature PA facilities or other food outlets (bakeries and fast-food outlets).

Conclusion:

These results indicate that disparities in spatial accessibility to PA facilities and to general food outlets may amplify the risk of overweight in socio-economically disadvantaged youth. These data should be relevant for influencing health policies and urban planning at both a national and local level.

Association between intake of dietary protein and 3-year-change in body growth among normal and overweight 6-year-old boys and girls (CoSCIS)

OBJECTIVE

Growth hormone (GH) affects linear growth and body composition, by increasing the secretion of insulin-like growth factor-I (IGF-I), muscle protein synthesis and lipolysis. The intake of protein (PROT) as well as the specific amino acids arginine (ARG) and lysine (LYS) stimulates GH/IGF-I secretion. The present paper aimed to investigate associations between PROT intake as well as intake of the specific amino acids ARG and LYS, and subsequent 3-year-change in linear growth and body composition among 6-year-old children.

DESIGN

Children's data were collected from Copenhagen (Denmark), during 2001-2002, and again 3 years later. Boys and girls were separated into normal weight and overweight, based on BMI quintiles. Fat-free mass index (FFMI) and fat mass index (FMI) were calculated. Associations between change (Delta) in height, FMI and FFMI, respectively, and habitual PROT intake as well as ARG and LYS were analysed by multiple linear regressions, adjusted for baseline height, FMI or FFMI and energy intake, age, physical activity and socio-economic status.

SETTING

Eighteen schools in two suburban communities in the Copenhagen (Denmark) area participated in the study.

SUBJECTS

In all, 223 children's data were collected for the present study.

RESULTS

High ARG intake was associated with linear growth (beta = 1.09 (se 0.54), P = 0.05) among girls. Furthermore, in girls, DeltaFMI had a stronger inverse association with high ARG intake, if it was combined with high LYS intake, instead of low LYS intake (P = 0.03). No associations were found in boys.ConclusionIn prepubertal girls, linear growth may be influenced by habitual ARG intake and body fat gain may be relatively prevented over time by the intake of the amino acids ARG and LYS.

Fatores socioeconômicos, demográficos, ambientais e comportamentais associados ao excesso de peso em adolescentes: uma revisão sistemática da literatura

OBJETIVO: Identificar fatores socioeconômicos, ambientais e comportamentais associados ao excesso de peso (EP) em adolescentes por meio de uma revisão sistemática da literatura. MÉTODOS: Foram consultadas seis bases de dados (Lilacs, Adolec, SciELO, Medline via Pubmed, ISI Web of Knowlwdge e Cochrane Library) entre os dias 3 e 13 de janeiro de 2008. Os descritores e respectivos termos MeSH utilizados foram: "sobrepeso", "obesidade", "adolescência", "adolescentes", "fatores de risco", "fatores associados". Foram avaliados artigos em inglês, espanhol e português publicados entre 1997 e 2007, e incluídos estudos observacionais que estudaram adolescentes com idades entre 10 e 19 anos, cujo desfecho era o EP diagnosticado por critérios internacionalmente utilizados. Foram excluídos estudos com base em amostras de conveniência ou que não investigavam fatores sociais, ambientais e psicocomportamentais entre as variáveis independentes. RESULTADOS: Da leitura dos títulos e resumos, e da aplicação inicial dos critérios de elegibilidade, resultaram 202 artigos. A revisão das publicações completas permitiu a inclusão e análise de 56 artigos. Observou-se que o nível socioeconômico associou-se inversamente com o EP em países desenvolvidos e de forma direta em países em desenvolvimento. Dieta para emagrecer, número de horas alocadas em TV/vídeo por dia, mãe e/ou pais obesos e ocorrência de EP na infância associaram-se diretamente com o EP. Foram identificados como fatores protetores o hábito de consumir desjejum e a prática de atividade física. CONCLUSÃO: Variáveis socioeconômicas, comportamentais, familiares e do início da vida associaram-se com EP e estas devem ser consideradas nas intervenções dirigidas para este agravo entre adolescentes.

Obesity in Mediterranean region (1997-2007): a systematic review

The objective of this review is to determine the distribution of obesity by geographical location, income, age and sex in the Mediterranean region during the last decade. A meta-analysis was conducted for 102 articles cited during the period (1997-2007) in Medline database (for 17 Mediterranean countries) searched during the summer of 2007 using the word 'obesity' and its related keywords. The study showed that adults were more obese than children in all Mediterranean continents and in different levels of income. The prevalence of obesity among European children was higher than among Asians. Also, European adults were more obese than European children. The total female adults were found to be more obese (median: 25.3%) than male adults (median: 20.0%). The regression model analysis indicated that male adults were more likely to be obese in the Euro-Med region. Taking different factors into consideration, it was noticed that Mediterranean adults, especially those in the European region, are at higher risk of obesity. Awareness programmes addressing the importance of adopting healthy dietary habits combined with physical activity should target the whole community in general and adults in particular. The findings could guide health planners for better management of obesity.

Association between family divorce and children's BMI and meal patterns: the GENDAI Study

The aim of this work was to explore the associations between family factors, including divorce, and children's overweight as well as eating and physical activity patterns in a population-based sample of healthy school-aged children. In this cross-sectional study, 1,138 children (53% girls; age: 11.2 +/- 0.7 years) from elementary schools in the Attica region participated. Their parents provided sociodemographic information, including their marital status. Overweight status classification was based on weight and height measurements and BMI evaluation. Children completed a physical activity checklist and a questionnaire on meal patterns and eating behaviors. The Eating Style score was calculated: the higher the score, the more frequent a child was engaged in less-structured feeding practices promoting food intake for reasons other than hunger. Analysis revealed significant association between family divorce and children's overweight: compared with children of married parents, those of divorced had significantly higher BMI levels (20.0 +/- 3.6 kg/m(2) vs. 21.3 +/- 3.4 kg/m(2), respectively, P = 0.007). Controlling for socioeconomic and physical activity factors, divorce remains a significant predictor of a higher BMI, along with older age, higher father's and mother's BMI, less children in the family, and more minutes of daily screen time. Children who had experienced a divorce in their family also reported higher Eating Style score, even after adjusting for potential confounders. In conclusion, in this sample of fifth and sixth graders, unfavorable family circumstances have been associated with children's overweight, as well as with aspects of their eating behavior, namely eating style in relation to conditions around food consumption and hunger, independent of other socioeconomic factors.

Sobrepeso/obesidade em adolescentes escolares da cidade de João Pessoa - PB: prevalência e associação com fatores demográficos e socioeconômicos

OBJETIVOS: O sobrepeso/obesidade na infância e adolescência tem sido considerado como um dos maiores problemas de saúde pública na atualidade, em função do rápido crescimento na sua prevalência e da associação com diversos problemas de saúde. Nesse sentido, o objetivo deste estudo foi determinar a prevalência de sobrepeso/obesidade em adolescentes escolares do ensino médio da cidade de João Pessoa - PB, e analisar sua associação com fatores demográficos e socioeconômicos. MÉTODOS: Participaram do estudo 2.402 escolares do ensino médio (escolas públicas e privadas), de 14 a 18 anos (16,5±0,2). Além de informações demográficas (sexo e idade) e socioeconômicas (classe econômica, escolaridade dos pais), os escolares referiram o peso corporal (kg) e a estatura (cm). O sobrepeso/obesidade foi determinado pelo índice de massa corporal (IMC=peso[kg]/estatura[m²]) a partir dos critérios propostos pelo International Obesity Task Force. RESULTADOS: A prevalência de sobrepeso/obesidade foi 10%, mostrando-se mais elevada nos rapazes do que nas moças (13,5% vs 7,4%, razão de prevalência [RP]=1,82; IC95%=1,42-2,32) e dissociada da idade em ambos os sexos. Os resultados da análise multivariável evidenciaram maior probabilidade de sobrepeso/obesidade nos rapazes que pertenciam às classes econômicas mais elevadas (RP=2,75; IC95%=1,56-4,82). Por outro lado, a probabilidade de sobrepeso/obesidade foi menor nas moças cujos pais apresentavam maior nível de escolaridade (RP=0,42; IC95%=0,21-0,87). CONCLUSÕES: A prevalência de sobrepeso/obesidade nos adolescentes escolares de João Pessoa - PB foi similar a que tem sido observado em estudos nacionais. Os rapazes mais ricos e as moças pobres foram os subgrupos de maior chance de apresentar sobrepeso/obesidade. Nesse sentido, no desenvolvimento de ações intervencionistas, deve-se levar em consideração as diferenças na freqüência de sobrepeso/obesidade em função dos estratos demográficos e socioeconômicos.

Socioeconomic status and adiposity in childhood: a systematic review of cross-sectional studies 1990-2005

BACKGROUND

Sobal and Stunkard's review (1989) of 34 studies from developed countries published after 1941, found inconsistent relationships between socioeconomic status (SES) and childhood adiposity. Inverse associations (36%), no associations (38%), and positive associations (26%) were found in similar proportions. In view of the trends in pediatric obesity, the relationship between SES and adiposity may have changed.

OBJECTIVE

To describe the cross-sectional association between SES and adiposity in school-age children from western developed countries in epidemiological studies since 1989.

METHODS AND PROCEDURES

PubMed database was searched to identify potentially relevant publications. Epidemiological studies from western developed countries presenting cross-sectional data on the bivariate association between an SES indicator and objectively measured adiposity in childhood (5-18 years), carried out after 1989 were included. SES indicators included parental education, parental occupation, family income, composite SES, and neighborhood SES.

RESULTS

Forty-five studies satisfied the review criteria. SES was inversely associated with adiposity in 19 studies (42%), there was no association in 12 studies (27%), and in 14 studies (31%) there was a mixture of no associations and inverse associations across subgroups. No positive SES-adiposity associations were seen in unadjusted analyses. With parental education as the SES indicator, inverse associations with adiposity were found in 15 of 20 studies (75%).

DISCUSSION

Research carried out within the past 15 years finds that associations between SES and adiposity in children are predominately inverse, and positive associations have all but disappeared. Research is needed to understand the mechanisms through which parental social class influences childhood adiposity.

Physical activity, overweight and central adiposity in Swedish children and adolescents: the European Youth Heart Study

Background

The aim of this work was to study the associations of physical activity (PA) and other factors predisposing to overweight, with overweight and central adiposity in children and adolescents.

Methods

A total of 557 Swedish children (9.5 ± 0.3 y) and 517 adolescents (15.6 ± 0.4 y) from the European Youth Heart Study participated in this study. Logistic regression analyses were used to examine the associations of PA, as measured by accelerometry, and other determinants (i.e. television viewing, birth weight, maternal educational level and parental overweight) with total and central adiposity. Body mass index and waist circumference cut-off values proposed by the IOTF and the Bogalusa Heart Study (i.e. waist measures for predicting risk factors clustering, hereinafter called high-risk waist circumference), respectively, were used. Fatness was estimated from skinfold thicknesses and dichotomized using the 85^th sex- and age-specific percentile (high/low).

Results

Children and adolescents who had a low level (first tertile) of vigorous PA, were more likely to be overweight (including obesity) and to have a high-risk waist circumference, than those with a high level (third tertile) of vigorous PA. Similarly, those subjects who had a low or middle level (second tertile) of total PA were more likely to be overweight than those who had a high level of total PA. Among the PA variables, only vigorous PA was associated with high total fatness. Birth weight and television viewing, were also associated with higher odds of having a high-risk waist circumference, but these associations were attenuated once either total or vigorous PA variable was included in the model. Those subjects who had two overweight parents were more likely to be overweight and to have a high-risk waist circumference independently of PA variables, compared to those whose parents were not overweight.

Conclusion

Low levels of total PA and especially vigorous PA may play an important role in the development of overweight and excess of central adiposity in children and adolescents, independently of a number of factors such as television viewing and birth weight. In addition, the data suggest that the association between television viewing and central fat deposition could be attenuated if enough vigorous PA is accumulated. Longitudinal and intervention studies are needed to confirm these findings.

Association between television in bedroom and adiposity throughout adolescence

OBJECTIVE

The objective was to determine if having a television (TV) in the bedroom is associated with physical activity (PA), TV/video viewing, and adiposity throughout adolescence.

RESEARCH METHODS AND PROCEDURES

Longitudinal data (September 2002 through June 2005) were analyzed of 379 initially 12-year-old French adolescents participating as controls in the Intervention Centered on Adolescents' Physical activity and Sedentary behavior (ICAPS). Presence of a TV set in the bedroom (TV(bedroom)) and leisure activities were obtained by questionnaire. There was annual assessment of BMI, waist circumference, and body fat by bioimpedance.

RESULTS

In boys but not girls, baseline TV(bedroom) was associated with higher TV/video viewing over time [odds ratio (OR) of high TV/video = 1.87; 95% confidence interval, 1.2 to 2.8] and less no-sport club participation (OR = 0.59; 95% confidence interval, 0.35 to 1.0). Both boys and girls with baseline TV(bedroom) had lower reading time (p < 0.0001 in boys; p = 0.04 in girls), while PA did not differ according to TV(bedroom) for boys or for girls. For boys only, baseline TV(bedroom) was associated with higher BMI (mean BMI over time 20.5 +/- 0.5 vs. 19.0 +/- 0.5 kg/m(2); p = 0.001), waist circumference (70.9 +/- 0.9 vs. 67.2 +/- 0.8 cm; p < 0.001), and body fat (15.9 +/- 0.9% vs. 13.5 +/- 0.9%; p < 0.001), without interaction with time. These relationships remained significant after adjustment for socioeconomic status. TV/video viewing explained 26%, 42%, and 36% of the relationships of TV(bedroom) with BMI, waist circumference, and body fat, respectively, while addition of other leisure activities in the models only marginally reduced the effects.

DISCUSSION

These results suggest the importance of keeping TV out of an adolescent's bedroom from an obesity prevention perspective but show gender differences.

The association of self-esteem, depression and body satisfaction with obesity among Turkish adolescents

BACKGROUND

The purpose of this study was to determine the prevalence of overweight and obesity and to examine the effects of actual weight status, perceived weight status and body satisfaction on self-esteem and depression in a high school population in Turkey.

METHODS

A cross-sectional survey of 2101 tenth-grade Turkish adolescents aged 15-18 was conducted. Body mass index (BMI) was calculated using weight and height measures. The overweight and obesity were based on the age- and gender-specific BMI cut-off points of the International Obesity Task Force values. Self-esteem was measured using the Rosenberg Self-Esteem Scale, and depression was measured using Children's Depression Inventory. Logistic regression analysis was used to examine relationships among the variables.

RESULTS

Based on BMI cut-off points, 9.0% of the students were overweight and 1.1% were obese. Logistic regression analysis indicated that (1) being male and being from a higher socio-economical level were important in the prediction of overweight based on BMI; (2) being female and being from a higher socio-economical level were important in the prediction of perceived overweight; (3) being female was important in the prediction of body dissatisfaction; (4) body dissatisfaction was related to low self-esteem and depression, perceived overweight was related only to low self-esteem but actual overweight was not related to low self-esteem and depression in adolescents.

CONCLUSION

The results of this study suggest that school-based adolescents in urban Turkey have a lower risk of overweight and obesity than adolescents in developed countries. The findings of this study suggest that psychological well-being of adolescents is more related to body satisfaction than actual and perceived weight status is.

Relationship of physical activity, fitness, and fatness with clustered metabolic risk in children and adolescents: the European youth heart study

OBJECTIVES

To examine the associations of physical activity (PA) at different levels and intensities and cardiorespiratory fitness (CRF) with a clustering of metabolic risk factors in children and adolescents with special consideration of body fat.

STUDY DESIGN

Total PA and intensity levels were measured by accelerometry in children (9 years, n = 273) and adolescents (15 years, n = 256). CRF was measured with a maximal ergometer bike test. Measured outcomes included fasting insulin, glucose, triglycerides, total and high-density lipoprotein cholesterol, blood pressure, and body fat. A metabolic risk score (MRS) was computed as the mean of the standardized outcome scores. A "non-obesity-MRS" was computed omitting body fat from the MRS. Analysis of variance and multiple regressions were used in the analysis.

RESULTS

Total and vigorous PA was inversely significantly associated with MRS in adolescent girls, the group with lowest PA, becoming insignificant when CRF was introduced in the analysis. Significant regression coefficients of total PA and CRF on non-obesity-MRS diminished when body fat was entered in the analysis.

CONCLUSIONS

CRF is more strongly correlated to metabolic risk than total PA, whereas body fat appears to have a pivotal role in the association of CRF with metabolic risk.

Family and school determinants of overweight in 13-year-old Portuguese adolescents

AIMS

To identify familial and school determinants of overweight in 13-year-old adolescents.

METHODS

All 27 public and 19 (79%) private schools allowed to contact age eligible students, 77.5% accepting to participate (1116 girls, 1045 boys). Self-administered questionnaires were completed and physical examination performed, including weight and height measurements. Overweight (> 95th percentile) and at risk of overweight (85th-95th) were defined using CDC standards. Its determinants were identified using logistic regression models, entering parents' education and all variables significantly associated in crude analysis.

RESULTS

Prevalence of overweight (10.2%) and at risk of overweight (16.5%) was not influenced by type of school, vending machines and number of school canteen meals. In girls, the prevalence of body mass index (BMI) > 85th percentile increased significantly with decreasing age at menarche (45.7% if menstruating before 11-year and 13.2% when pre-menarche), and increasing parental BMI or time spent on sedentary activities. In multivariate analysis, age at menarche and increasing parental BMI remained significant risks in girls. In boys, besides parental BMI, ever smoking, sleeping < 9 h and sedentary leisure activities were significant determinants.

CONCLUSIONS

Food offered at school had no significant impact on adolescents overweight, which was mainly dependent on parental anthropometrics and leisure time activities.

Socio-demographic and cultural comparison of overweight and obesity risk and prevalence in adolescents in Southern California and Wuhan, China

PURPOSE

This study performed parallel analyses on two large samples of seventh graders living in Los Angeles, California and in Wuhan, China to make direct comparisons of overweight and obesity risks in Western and Eastern cultural environments.

METHODS

Two representative samples of 1772 and 1896 seventh grade students were randomly selected from the public or parochial middle schools in the greater Los Angeles area of Southern California in the United States, and public schools in Wuhan city of China. Two body mass index (BMI) references recently established by the U.S. National Center for Health Statistics (NCHS) and the International Obesity Task Force (IOTF), respectively, were used to define overweight (85th < or = BMI < 95th percentile) and obesity (BMI > or = 95th percentile). Logistic regressions were conducted to examine relationships between socioeconomic status (SES) and obesity risk.

RESULTS

The prevalence rates of combined overweight and obesity in Los Angeles and in Wuhan were 43.1% and 12.1%, respectively, by the US-NCHS reference, and 45.8% and 11.9%, respectively, by the IOTF reference. Chinese-American adolescents had higher prevalence rates for overweight and obesity than those from China. SES was positively related to the risk of overweight and obesity in the Chinese sample, whereas a negative association was found in Southern California adolescents. Urbanicity was significantly positively related to higher overweight and obesity prevalence.

CONCLUSION

Different overweight and obesity prevalence estimates and SES effects were observed for American and Chinese adolescent samples. Research on the underlying mechanisms is needed to help us to set up a tailored program for obesity prevention in Eastern and Western cultural environments.

ICAPS: a multilevel program to improve physical activity in adolescents

OBJECTIVES

ICAPS (Intervention Centred on Adolescents' Physical activity and Sedentary behaviour) is aimed at preventing excessive weight gain and cardiovascular risk in adolescents by promoting physical activity (PA) with an emphasis on recreational and daily-life PA, with a lifelong perspective.

DESIGN

Randomized study designed to last for four years. Study cohort constituted of 954 first-level students (91% of eligible pupils), aged 11.7 +/- 0.6 y (mean +/- SD) from four pairs of schools randomly selected in eastern France, after sociogeographical stratification. In each pair, intervention status was randomised at school-level. The program, not limited to school settings, involves multiple partners with three objectives: 1) changing attitudes through debates and access to attractive activities during breaks and after-school hours, 2) encouraging social support, 3) providing environmental conditions that enable PA. Adapted times and places, open participation, emphasis on fun, meeting with others and absence of competitive aspects are used to reduce usual barriers to PA. Accessibility and safety are permanent concerns.

RESULTS

Prevalence of overweight was 23.7%. High participation rates were attained (50% participated in at least one weekly activity). At six-month, the proportion of intervention adolescents not performing supervised PA out of academic PA was reduced by half (36% to 17% vs 42% to 42% in controls P < 10-4); the proportion of those spending > 3 h/day in sedentary occupations decreased (34% to 28% vs 27% to 36%; P < 10-4).

CONCLUSION

These data demonstrate the feasibility of implementing a multilevel PA intervention program in adolescents. Six-month results document increased PA and decreased sedentary behaviour.

Tracking and prevalence of cardiovascular disease risk factors across socio-economic classes: a longitudinal substudy of the European Youth Heart Study

BACKGROUND

The highest prevalence of several cardiovascular disease risk factors including obesity, smoking and low physical activity level is observed in adults of low socioeconomic status. This study investigates whether tracking of body mass index and physical fitness from childhood to adolescence differs between groups of socioeconomic status. Furthermore the study investigates whether social class differences in the prevalence of overweight and low physical fitness exist or develop within the age range from childhood to adolescence.

METHODS

In all, 384 school children were followed for a period of six years (from third to ninth grade). Physical fitness was determined by a progressive maximal cycle ergometer test and the classification of overweight was based on body mass index cut-points proposed by the International Obesity Task Force. Socioeconomic status was defined according to The International Standard Classification of Occupation scheme.

RESULTS

Moderate and moderately high tracking was observed for physical fitness and body mass index, respectively. No significant difference in tracking was observed between groups of socioeconomic status. A significant social gradient was observed in both the prevalence of overweight and low physical fitness in the 14-16-year-old adolescents, whereas at the age of 8-10 years, only the prevalence of low physical fitness showed a significant inverse relation to socioeconomic status. The odds of both developing and maintaining risk during the measurement period were estimated as bigger in the group of low socioeconomic status than in the group of high socioeconomic status, although differences were significant only with respect to the odds of developing overweight.

CONCLUSION

The results indicate that the fundamental possibilities of predicting overweight and low physical fitness at an early point in time are the same for different groups of socio-economic status. Furthermore, the observed development of social inequalities in the absolute prevalence of overweight and low physical fitness underline the need for broad preventive efforts targeting children of low socioeconomic status in early childhood.

Physical activity is inversely related to waist circumference in 12-y-old French adolescents

BACKGROUND AND OBJECTIVE

Waist circumference (W) has been shown to be a good predictor of cardiovascular risk. The aim of this study was to investigate whether physical activity (PA) is related to W in adolescents as previously shown in adults.

DESIGN AND SUBJECTS

Cross-sectional population-based survey of 2,714 12-y-old adolescents from the eastern part of France.

MEASUREMENTS

Body mass index (BMI) and W were measured. Structured PA, active commuting to and from school and sedentary activities (SED), for example television viewing, computer/video games and reading and different potential confounders (dietary habits, parental overweight, family annual income tax and educational level) were assessed by a questionnaire.

RESULTS

The adolescents had a mean BMI of 19.0+/-3.4 kg/m2, and 20.2% of them were overweight, with no gender difference. Boys had a greater W than girls (67.6+/-9.1 vs 65.7+/-8.9 cm, P<0.0001). In all, 42% of the girls and 25% of the boys did not practice any structured PA outside school and less than 40% of the adolescents commuted actively to school more than 20 min/day. About one-third of the adolescents devoted more than 2 h/day to SED. In univariate analyses, BMI was negatively associated with structured PA but significantly only for girls (P<0.01) and positively associated with SED for both genders (P<0.0001 for girls, P<0.01 for boys). W was negatively associated with structured PA and positively associated with SED both in girls (P<0.0001 and P=0.03, respectively) and boys (P<0.01 and P=0.08, respectively). Multiple general linear models show that SED is associated with BMI, independently of structured PA, in both genders. On the other hand, structured PA was inversely associated with W, independently of SED. The inverse relation between structured PA and W persisted after additional adjustment on BMI, with a greater effect of PA for the adolescents with higher BMI.

CONCLUSIONS

In 12-y-old adolescents, structured PA is inversely associated with W, an indicator of total adiposity but also more specifically of abdominal fat. This suggests that PA may have a beneficial effect on youth metabolic and cardiovascular risks, in particular in the presence of overweight..

Associations between physical activity and fat mass in adolescents: the Stockholm Weight Development Study

BACKGROUND

Obesity is multifactorial. However, the accumulation of fat mass (FM) is proposed to be due to a positive energy balance, which may be caused by reduced physical activity (PA).

OBJECTIVE

The objectives of the study were to describe the independent associations between PA and FM in adolescents and to describe the intergenerational association of FM between mothers and their offspring.

DESIGN

We conducted a cross-sectional study in 445 (190 M, 255 F) 17-y-old adolescents and their mothers. PA was assessed with a self-reported questionnaire and validated by comparison with accelerometric data in a subsample of the cohort. Body composition was measured by using air-displacement plethysmography.

RESULTS

Males were significantly more active than were females (P<0.01). PA was significantly and inversely associated with FM (beta=-3.63, P=0.005) and percentage FM (beta=-3.117, P=0.017) in males but not in females (beta=-0.576, P=0.54; beta=-0.532, P=0.59, respectively) after adjustment for birth weight and maternal FM and education level. However, FM and percentage FM in females were significantly associated with maternal FM (beta=0.159, P<0.0001; beta=0.145, P=0.002, respectively) and education level (beta=-1.048, P<0.005; beta=-1.085, P=0.006, respectively). No such associations were observed in males.

CONCLUSIONS

PA was independently associated with FM in males but not in females. The data also showed an intergenerational association of FM between mothers and their daughters but not between mothers and their sons.

Parent-child physical activity relationships in 12-year old French students do not depend on family socioeconomic status

OBJECTIVES

Regular physical activity (PA) in young needs to be promoted to prevent obesity and subsequent diabetes. Influences of parental PA on adolescents' activity level have been studied with discordant results and the effect of socioeconomic status (SES) on these relationships is not clarified.

METHODS

Cross-sectional population-based survey of about 3000 12-year old French students and their parents. Familial associations were assessed with logistic regression models taking into account SES and children's and parents' corpulence. Sport involvement and sedentary behaviors were assessed by standardized questionnaires filled out separately by children and parents, the latter also reporting their educational data and family income tax.

RESULTS

Participation in structured PA outside school was higher for boys (74%) than for girls (58%, p<10-5) and a high sedentary behavior (watching television, playing computer/video games and reading > or =2h/day) was observed in one-third of the sample, both in boys and in girls. Children were more likely to participate in structured PA outside school when both parents practiced sport as compared to neither parent practicing it, with an odd ratio OR (95%CI) of 1.97 (1.4-2.8) for boys and 1.56 (1.2-2.1) for girls. Familial associations of inactivity were significant for boys only. A greater percentage of adolescents had a high level of sedentary behavior when both parents versus no parents watched television > 2h/day (OR 1.95 (1.52.6)). Parent-child physical activity relationships were not modified by the family SES or the children's or parents' weight status.

CONCLUSION

Parental involvement in sport is an important correlate of a young adolescent's participation in structured PA outside school, whatever the family SES or corpulence of the family members.

Assessing prevalence of overweight and obesity through self-reports of height and weight by high school students in Taipei, Taiwan

This study compared consistency of age- and gender-specific self-reported height and weight and calculated body mass index among a sample of high school students in Taipei County, Taiwan to reference values for Taiwanese school-aged youth obtained through national studies. Taipei high school students provided self-reports of height and weight that were similar to national reference values. Use of self-reported height and weight in this sample appeared warranted and may reliably be used to calculate aggregate indices of body mass, overweight, and obesity. This study compared prevalence of overweight and obesity in the current sample with other adolescent populations using international criteria (International Task Force on Obesity). Using these criteria, 17.6% of boys and 9.4% of girls met the definition of overweight and 3.7% of boys and 1.6% of girls met the definition of obesity. While use of self-reported height and weight appears justified in this sample, researchers should not assume self-report measures will always be accurate. Researchers considering use of self-reported height and weight should compare their results to normative reference values when possible to increase confidence in using self-report measures of height and weight.

Intervention centred on adolescents' physical activity and sedentary behaviour (ICAPS): concept and 6-month results

OBJECTIVE

To evaluate the 6-month impact of a physical activity (PA) multilevel intervention on activity patterns and psychological predictors of PA among adolescents. The intervention was directed at changing knowledge and attitudes and at providing social support and environmental conditions that encourage PA of adolescents inside and outside school.

SUBJECTS AND DESIGN

Randomised, controlled ongoing field trial (ICAPS) in middle-school's first-level adolescents from eight schools selected in the department of the Bas-Rhin (Eastern France) with a cohort of 954 adolescents (92% of the eligible students) initially aged 11.7+/-0.6 y. The 6-month changes in participation in leisure organised PA (LOPA), high sedentary (SED) behaviour (>3 h/day), self-efficacy (SELF) and intention (INTENT) towards PA were analysed after controlling for baseline measures and different covariables (age, overweight, socioprofessional occupation), taking into account the cluster randomisation design.

RESULTS

The proportion of intervention adolescents not engaged in organised PA was reduced by 50% whereas it was unchanged among control students. After adjustment for baseline covariables, LOPA participation significantly increased among the intervention adolescents (odds ratio (95% confidence interval) (OR)=3.38 (1.42-8.05) in girls; 1.73 (1.12-2.66) in boys), while high SED was reduced (OR=0.54 (0.38-0.77) in girls; 0.52 (0.35-0.76) in boys). The intervention improved SELF in girls, whatever their baseline LOPA (P<10(-4)) and INTENT in girls with no baseline LOPA (P=0.04). SELF tended to improve in boys with no baseline LOPA, without reaching statistical significance. When included in the regression, follow-up LOPA was associated with improvement of SELF in girls (P=0.02) and of INTENT in girls with no baseline PA (P<0.02). The intervention effect was then attenuated.

CONCLUSION

After 6 months of intervention, ICAPS was associated with a significant improvement of activity patterns and psychological predictors, indicating a promising approach for modifying the long-term PA level of adolescents.