Child overweight in France and its relationship with physical activity, sedentary behaviour and socioeconomic status

Prevalence of non-communicable diseases in Brazilian children: follow-up at school age of two Brazilian birth cohorts of the 1990's

Background

Few cohort studies have been conducted in low and middle-income countries to investigate non-communicable diseases among school-aged children. This article aims to describe the methodology of two birth cohorts, started in 1994 in Ribeirão Preto (RP), a more developed city, and in 1997/98 in São Luís (SL), a less developed town.

Methods

Prevalences of some non-communicable diseases during the first follow-up of these cohorts were estimated and compared. Data on singleton live births were obtained at birth (2858 in RP and 2443 in SL). The follow-up at school age was conducted in RP in 2004/05, when the children were 9-11 years old and in SL in 2005/06, when the children were 7-9 years old. Follow-up rates were 68.7% in RP (790 included) and 72.7% in SL (673 participants). The groups of low (<2500 g) and high (≥ 4250 g) birthweight were oversampled and estimates were corrected by weighting.

Results

In the more developed city there was a higher percentage of non-nutritive sucking habits (69.1% vs 47.9%), lifetime bottle use (89.6% vs 68.3%), higher prevalence of primary headache in the last 15 days (27.9% vs 13.0%), higher positive skin tests for allergens (44.3% vs 25.3%) and higher prevalence of overweight (18.2% vs 3.6%), obesity (9.5% vs 1.8%) and hypertension (10.9% vs 4.6%). In the less developed city there was a larger percentage of children with below average cognitive function (28.9% vs 12.2%), mental health problems (47.4% vs 38.4%), depression (21.6% vs 6.0%) and underweight (5.8% vs 3.6%). There was no difference in the prevalence of bruxism, recurrent abdominal pain, asthma and bronchial hyperresponsiveness between cities.

Conclusions

Some non-communicable diseases were highly prevalent, especially in the more developed city. Some high rates suggest that the burden of non-communicable diseases will be high in the future, especially mental health problems.

Influence of physical inactivity on associations between single nucleotide polymorphisms and genetic predisposition to childhood obesity

Childhood obesity is a complex disease that is influenced by both genetic and environmental factors. The authors' aim was to determine whether sedentary behavior and physical activity modulate the association between single nucleotide polymorphisms (SNPs) and obesity risk in Chinese children. A population-based study was carried out in 2,848 children (6-18 years of age) in Beijing, China, in 2004. It included 1,229 obese cases and 1,619 normal-weight controls. Lifestyle information was collected through the use of a validated questionnaire, and 6 SNPs were genotyped. The association between the 6 SNPs and obesity risk was modulated by sedentary behavior and physical activity. A higher risk of obesity was observed in children who carried the high-risk alleles of the 6 SNPs and engaged in sedentary behavior ≥2 hours/day outside of school or participated in low or moderate physical activity. Most notably, the association between 5 SNPs (Fas apoptotic inhibitory molecule 2 rs7138803, Niemann-Pick disease, type C1 rs1805081, fat mass- and obesity-associated gene rs6499640, melanocortin 4 receptor gene rs17782313, and brain-derived neurotrophic factor rs6265) and obesity risk was only observed in children who had moderate-to-low physical activity levels or engaged in sedentary behavior, regardless of which risk alleles they carried. The results indicated that encouraging less sedentary behavior and higher levels of physical activity could alleviate the influence of risk alleles on genetic predisposition to childhood obesity, thereby serving as a promising prevention strategy.

Characteristics of energy under-reporting in children and adolescents

Under-reporting (UR) of food intake is an issue of concern, as it may distort the relationships studied between diet and health. This topic has been scarcely addressed in children. The objective of the study was to assess the extent of UR in French children and investigate associated covariates. A total of 1455 children aged 3-17 years were taken from the nationally representative cross-sectional French étude Individuelle Nationale des Consommations Alimentaires (INCA2) dietary survey (2006-7). Food intake was reported in a 7 d diet record. Socio-economic status, sedentary behaviour, weight perception variables and food habits were collected by questionnaires. Weight and height were measured. Under-reporters were identified according to the Goldberg criterion adapted to children. Multivariate logistic regressions investigated the associations between UR and covariates. Rates of under-reporters were 4·9 and 26·0 % in children aged 3-10 and 11-17 years, respectively (P < 0·0001), without significant differences between boys and girls. Overall, UR was positively associated with a lower socio-economic status, overweight, skipping breakfast and dinner, a higher contribution of proteins to energy intake (EI), and a lower contribution of simple carbohydrates to EI. Under-reporters aged 3-10 years also had a higher sedentary behaviour and a lower snack-eating frequency. In adolescents, UR was also associated with a less-frequent school canteen attendance, a perception of being overweight, a wish to weigh less, and current and past restrictive diets. In conclusion, under-reporters differ from plausible reporters in several characteristics related to diet, lifestyle, weight status and socio-economic status. Therefore, it is important to consider this differential UR bias when investigating diet-disease associations in children.

Early-life determinants of overweight and obesity: a review of systematic reviews

The aim of this paper was to review the evidence for early-life (from conception to 5 years of age) determinants of obesity. The design is review of published systematic reviews. Data sources included Medline, Embase, Web of Science, Cochrane Library, CINAHL, PsycINFO. Identification of 22 eligible reviews from a database of 12,021 independent publications. Quality of selected reviews assessed using the Assessment of Multiple Systematic Reviews score. Articles published after the reviews were used to confirm results. No review was classified as high quality, 11 as moderate and 11 as low. Factors associated with later overweight and obesity: maternal diabetes, maternal smoking, rapid infant growth, no or short breastfeeding, obesity in infancy, short sleep duration, <30 min of daily physical activity, consumption of sugar-sweetened beverages. Other factors were identified as potentially relevant, although the size of their effect is difficult to estimate. Maternal smoking, breastfeeding, infant size and growth, short sleep duration and television viewing are supported by better-quality reviews. It is difficult to establish a causal association between possible determinants and obesity, and the relative importance of each determinant. Future research should focus on early-life interventions to confirm the role of protective and risk factors and to tackle the high burden obesity represents for present and future generations.

Socio-economic and demographic variations in school lunch participation of French children aged 3-17 years

OBJECTIVE

To assess school canteen attendance in a French nationally representative sample of children and to analyse its association with the socio-economic and demographic characteristics of the children and their families.

DESIGN

Data from the second French national cross-sectional food consumption survey (INCA2), performed in 2006-2007, were used. Information on usual weekly school canteen attendance was collected through a self-reported questionnaire, and demographic and socio-economic variables through a face-to-face questionnaire. The associations between school canteen attendance and the socio-economic and demographic variables were investigated by multivariate logistic regression analyses.

SETTING

The INCA2 sample was representative of the children aged 3-17 years in France.

SUBJECT

Analysis was performed on 1413 schoolchildren who completed the school canteen attendance questions.

RESULTS

Some 65·6 % of schoolchildren aged 3-17 years had school lunch at least once weekly. This rate of attendance was positively correlated with age. Whatever the school level, school canteen attendance was positively associated with the educational level of the caregiver/parent. In pre- and elementary-school children, enrolment at the school canteen was also higher when the caregiver/parent worked, or in single-parent families. In secondary-school children, school lunch participation decreased with children living in more densely populated areas and increased with the level of the household's living standards.

CONCLUSIONS

School canteen attendance was positively associated with children's socio-economic background. This could reduce the effectiveness of the forthcoming school meal composition regulations designed to improve the diet of children from deprived backgrounds, who are more likely to have unhealthy food habits.

Systematic review of correlates of screen-viewing among young children

OBJECTIVE

The aims of this review were to: (I) synthesise current research on the correlates of screen-viewing among young children (< or = 7 years old); and (II) identify gaps in the study of these correlates.

METHODS

71 English-language studies published between 1980 and February 2009 were extracted from computerized literature searches and bibliographies of primary studies.

RESULTS

Variables positively associated with screen-viewing were age, ethnicity, family TV viewing, family factors (maternal depressive symptoms and parental body mass) and media access. Variables negatively associated were socioeconomic indicators, parental rules and safety. Mother's age, mother's employment and presence of a TV set in a child's bedroom were found to be unclearly associated with screen-viewing behaviour. Gender, marital status, father's age and number of TVs were not associated with screen-viewing behaviour.

CONCLUSIONS

Few modifiable variables for future research implications were identified. Findings suggest that research on correlates of screen-viewing among young children is limited. However, there are some clear correlates on which future interventions could be tailored (age, ethnicity, some socioeconomic indicators, family TV viewing, some family factors, parental rules and safety). Subsequent research is needed both to further test some of the correlates and to review the correlates for strength of associations.

Overweight and obesity in infants and pre-school children in the European Union: a review of existing data

The objective of this study was to synthesize available information on prevalence and time trends of overweight and obesity in pre-school children in the European Union. Retrieval and analysis or re-analysis of existing data were carried out. Data sources include WHO databases, Medline and Google, contact with authors of published and unpublished documents. Data were analysed using the International Obesity Task Force reference and cut-offs, and the WHO standard. Data were available from 18/27 countries. Comparisons were problematic because of different definitions and methods of data collection and analysis. The reported prevalence of overweight plus obesity at 4 years ranges from 11.8% in Romania (2004) to 32.3% in Spain (1998-2000). Countries in the Mediterranean region and the British islands report higher rates than those in middle, northern and eastern Europe. Rates are generally higher in girls than in boys. With the possible exception of England, there was no obvious trend towards increasing prevalence in the past 20-30 years in the five countries with data. The use of the WHO standard with cut-offs at 1, 2 and 3 standard deviations yields lower rates and removes gender differences. Data on overweight and obesity in pre-school children are scarce; their interpretation is difficult. Standard methods of surveillance, and research and policies on prevention and treatment, are urgently needed.

Influence of socio-economic status on habitual physical activity and sedentary behavior in 8- to 11-year old children

BACKGROUND

While socio-economic status has been shown to be an important determinant of health and physical activity in adults, results for children and adolescents are less consistent. The purpose of this study, therefore, is to examine whether physical activity and sedentary behavior differs in children by socio-economic status (SES) independent of body mass index.

METHODS

Data were from two cohorts including 271 children (117 males; 154 females) in study 1 and 131 children in study 2 (63 males; 68 females). The average age was 9.6 and 8.8 years respectively. Height and body mass were assessed according to standard procedures and body mass index (BMI, kg/m2) was calculated. Parent-reported household income was used to determine SES. Habitual, free-living physical activity (PA) was assessed by a pedometer (steps/day) in study 1 and accelerometer (time spent in moderate-to-vigorous PA) in study 2. Self-reported time spent watching TV and on the computer was used as measure of sedentary behavior. Differences in PA and sedentary behavior by SES were initially tested using ANOVA. Further analyses used ANCOVA controlling for BMI, as well as leg length in the pedometer cohort.

RESULTS

In study 1, mean daily steps differed significantly among SES groups with lower SES groups approximating 10,500 steps/day compared to about 12,000 steps/day in the higher SES groups. These differences remained significant (p < 0.05) when controlling for leg length. Lower SES children, however, had higher body mass and BMI compared to higher SES groups (p < 0.05) and PA no longer remained significant when further controlling for BMI. In study 2 results depended on the methodology used to determine time spent in moderate-to-vigorous physical activity (MVPA). Only one equation resulted in significant group differences (p = 0.015), and these differences remained after controlling for BMI. Significant differences between SES groups were shown for sedentary behavior in both cohorts (P < 0.05) with higher SES groups spending less time watching TV than low SES groups.

CONCLUSIONS

Children from a low SES show a trend of lower PA levels and spend more time in sedentary behavior than high SES children; however, differences in PA were influenced by BMI. The higher BMI in these children might be another factor contributing to increased health risks among low SES children compared to children from with a higher SES.

Child overweight, associated psychopathology, and social functioning: a French school-based survey in 6- to 11-year-old children

The aim of this study was to estimate the prevalence of child overweight in a regional sample of primary school-aged children, and to examine the relationships among child overweight, psychopathology, and social functioning. A cross-sectional survey was conducted in 2004 in 100 primary schools of a large French region, with 2,341 children aged 6-11 randomly selected. Child weight and height, lifestyle variables (leisure-time physical activity (LTPA), watching television (TV), playing video games), and socioeconomic characteristics were collected in parent-administered questionnaires. Child psychopathology outcomes were assessed using child- and parent-reported instruments (Dominic Interactive (DI) and Strengths and Difficulties Questionnaire (SDQ)). Overweight and obesity were estimated according to the International Obesity Task Force (IOTF) definition. Response rates to the parent questionnaire and DI were 57.4 and 95.1%, respectively. Final sample size was 1,030 children. According to the IOTF, 17.3% of the children were overweight, of whom 3.3% were obese. In univariate analysis, correlates of overweight were low parental education, low monthly income, Disadvantaged School Areas (DSAs), self-reported generalized anxiety, parent-reported conduct disorders, emotional problems, and peer difficulties. High monthly income was less frequently associated with overweight. In multivariate analysis, parent-reported peer difficulties (odds ratio (OR) = 2.06; 95% confidence interval = 1.27-3.35) and DSAs (1.88; 1.03-3.44) were independent factors significantly associated with child overweight. There was a trend of being overweight with elevated TV times (P for trend = 0.02). The psychosocial burden of excess weight appears to be significant even in young children. Findings should be considered for preventing strategies and public health interventions. School-based overweight prevention programs should be implemented first in disadvantaged areas together with information about weight stigmatization and discrimination.

Determinants of the prevalence and incidence of overweight in children and adolescents

Objective

To systematically analyse determinants of overweight prevalence and incidence in children and adolescents, as a basis of treatment and prevention.

Design

Cross-sectional and longitudinal data of the Kiel Obesity Prevention Study (KOPS).

Setting

Schools in Kiel, Germany.

Subjects

Cross-sectional data from 6249 students aged 5–16 years and 4-year longitudinal data from 1087 children aged 5–11 years. Weight status of students was assessed and familial factors (weight status of parents and siblings, smoking habits), social factors (socio-economic status, nationality, single parenting), birth weight as well as lifestyle variables (physical activity, media time, nutrition) were considered as independent variables in multivariate logistic regression analyses to predict the likelihood of the student being overweight.

Results

The cross-sectional data revealed the prevalence of overweight as 18·3 % in boys and 19·2 % in girls. In both sexes determinants of overweight prevalence were overweight and obese parents, overweight siblings, parental smoking, single parenthood and non-German nationality. High birth weight and low physical activity additionally increased the risk in boys. High media time and low parental education were significant determinants in girls. Effect of media time was mediated by maternal weight status in boys as well as by socio-economic status and age in girls. From the longitudinal data, the 4-year cumulative incidence of overweight was 10·0 % in boys and 8·2 % in girls. Parental obesity, parental smoking and low physical activity were determinants of overweight incidence in boys, whereas paternal obesity increased the risk in girls.

Conclusions

Treatment and prevention should address family and social determinants with a focus on physical activity and media use.

Sedentary behaviours and socio-economic status in Spanish adolescents: the AVENA study

BACKGROUND

This study aimed to describe the influence of socio-economic status (SES) on the prevalence sedentary behaviours among Spanish adolescents.

METHODS

Cross-sectional data from Spanish adolescents from the Alimentación y Valoración del Estado Nutricional de los Adolescentes (AVENA) Study (2002). A national representative sample of 1776 adolescents aged 13-18.5 years provided information about time spent watching television (TV), playing with computer or videogames and studying. Parental education and occupation were assessed as SES. Participants were categorized by gender, age, parental education and occupation. Logistic regression models were used.

RESULTS

No gender differences were found for TV viewing. For computer and videogames use (weekdays), more boys played >3 h/day (P < 0.001), whereas a higher percentage of girls reported studying >3 h/day (P < 0.001). Among boys, parental education and occupation were inversely associated with TV viewing, parental occupation directly associated with study and maternal education inversely with computer and videogames use during weekdays (all P < 0.05). For girls, parental occupation was inversely associated with TV viewing.

CONCLUSION

Spanish adolescents presented different sedentary patterns according to age, gender and SES. Boys reported more time engaged in electronic games, whereas girls reported more time studying. Parental occupation had more influence than parental education on the time spent in sedentary behaviours.

A study of fluid intake from beverages in a sample of healthy French children, adolescents and adults

Background/Objectives:

To assess the intake of fluid in healthy French children, adolescents, adults and seniors, considering amounts, types of beverages, time and place of consumption.

Subjects/Methods:

Data regarding fluid intake were extracted and analyzed from the National Intake Survey, which was conducted in quota samples of the French population (Comportement et Consommations Alimentaires en France study). Seven-day questionnaires were administered to free-living individuals in 2002–2003. A total of 566 children (aged 6–11 years), 333 adolescents (aged 12–19 years), 831 adults (aged 20–54 years) and 443 seniors (aged ⩾55 years) were included in this study.

Results:

The average total intake of fluid was 1–1.3 l per day depending on age groups. Water accounted for about one-half of daily fluid intake. The contribution of other types of beverages varied with age (for example, dairy drinks in children and adolescents; alcoholic drinks in adults and seniors). Intake of sodas (including regular and light) was highest in adolescents (169 ml a day). Beverages were mainly consumed at home during meals.

Conclusions:

This is the first description of fluid intake in French children, adolescents, adults and seniors, considering amounts, types of beverages, time and place of intake. It shows that water is the main source of fluid in all age groups. Selection of various types of beverages is different according to age.

Effects of TV time and other sedentary pursuits

Television (TV) viewing is the dominant recreational pastime at all ages, especially for children and adolescents. Many studies have shown that higher TV viewing hours are associated with higher body mass index (BMI), lower levels of fitness and higher blood cholesterol levels. Although the effect size estimated from observational studies is small (with TV viewing explaining very little of the variance in BMI), the results of intervention studies show large effect sizes. The potential mediators of the effect of higher TV viewing on higher BMI include less time for physical activity, reduced resting metabolic rate (for which there is little supporting evidence) and increased energy intake (from more eating while watching TV and a greater exposure to marketing of energy dense foods). Electronic games may have an effect on unhealthy weight gain, but are less related to increased energy intake and their usage is relatively new, making effect size difficult to determine. Thus, TV viewing does not explain much of the differences in body size between individuals or the rise in obesity over time, perhaps because of the uniformly high, but relatively stable, TV viewing hours. Reducing TV viewing hours is a difficult prospect because potential actions, such as social marketing and education, are likely to be relatively weak interventions, although the evidence would suggest that, if viewing could be reduced, it could have a significant impact on reducing obesity prevalence. Regulations to reduce the heavy marketing of energy dense foods and beverages on TV may be the most effective public health measure available to minimize the impact of TV viewing on unhealthy weight gain.

Risk factors for overweight and obesity in French adolescents: physical activity, sedentary behavior and parental characteristics

OBJECTIVE

We determined the prevalence by age and sex and associated factors of overweight and obesity in French adolescents.

METHODS

We conducted a cross-sectional study of 2385 adolescents aged 11-18 y (1213 boys and 1172 girls) from middle and high schools in the Aquitaine region (southwest France) in 2004-2005. Weight and height were measured, and adolescents filled in a questionnaire about their characteristics and those of their parents. Overweight and obesity were defined according to the age- and sex-specific body mass index cutoff points of the International Obesity Task force.

RESULTS

Prevalence of overweight (obesity included) was greater in boys and younger children. The odds ratio (OR) for an adolescent being overweight increased with parents' being overweight (at least one parent overweight, OR 1.97, 1.48-2.62, P<0.0001), low paternal socioeconomic status (OR 1.78, 1.22-2.60, P<0.01) and sedentary behavior (22 h/wk, OR 1.33, 1.02-1.74, P<0.05), and decreased with physical activity of parents (at least one parent active, OR 0.67, 0.51-0.89, P=0.01).

CONCLUSION

Our data support the hypothesis that parental overweight and low socioeconomic status and adolescents' sedentary behavior are strong risk factors for adolescent overweight and obesity, and that parents active lifestyle is associated with a lower risk of overweight in their adolescents.

Socio-economic differentiation of the growth and the dietary intake of Polish boys aged 7-16 years

BACKGROUND

The period of the constitutional transformation, apart from many advantages, has generated a number of serious problems that may affect the biological state of children and adolescents in Poland.

AIM

The study documented socio-economic differentiation of growth and dietary intake of boys.

SUBJECTS AND METHODS

The research involved 523 boys aged 7-16; 54.4% of subjects came from Kielce (a city with a population of over 200 000) and 45.6% came from rural areas - from a region underprivileged in terms of economic development, with a majority of its inhabitants living off the land. Height and weight measurements of the subjects were taken, which allowed for computation of BMI. Dietary intake was assessed using the interview method for 24 h dietary recall. A multifactor variance analysis for unequal numbers in subclasses was applied to estimate the influence of socio-economic factors such as place of residence, mother's education and number of children in the family on somatic traits and on nutrient intake.

RESULTS

Urban boys whose mothers had experienced higher education were characterized by the greatest height (p<0.000). The percentage of the investigated subjects with an excessive body mass was over twice as high among boys in families with one or two children (15.0%) than among boys in families with three or more children (6.1%), and twice as high among urban boys (14.1%) in comparison with rural boys (7.0%). No significant differences in the energy value of daily food intake in each social group were found. The diet of rural boys included a lower percentage of energy intake derived from protein (10.7%) than that of urban boys (12.4%). This percentage decreased together with the lowering level of mother's education. The greatest amount of minerals and vitamins was found in the diets of boys whose mothers had higher education and lived in a city.

CONCLUSIONS

Diets of boys with the greatest body height were also characterized by a greater content of mineral components and vitamins, and a greater percentage of energy derived from protein. The relative body mass of the investigated subjects was probably more influenced by factors other than nutrition, i.e. mostly physical activity.

Use of television, videogames, and computer among children and adolescents in Italy

Background

This survey determined the practices about television (video inclusive), videogames, and computer use in children and adolescents in Italy.

Methods

A self-administered anonymous questionnaire covered socio-demographics; behaviour about television, videogames, computer, and sports; parental control over television, videogames, and computer.

Results

Overall, 54.1% and 61% always ate lunch or dinner in front of the television, 89.5% had a television in the bedroom while 52.5% of them always watched television there, and 49% indicated that parents controlled the content of what was watched on television. The overall mean length of time daily spent on television viewing (2.8 hours) and the frequency of watching for at least two hours per day (74.9%) were significantly associated with older age, always ate lunch or dinner while watching television, spent more time playing videogames and using computer. Those with parents from a lower socio-economic level were also more likely to spend more minutes viewing television. Two-thirds played videogames for 1.6 daily hours and more time was spent by those younger, males, with parents that do not control them, who watched more television, and who spent more time at the computer. The computer was used by 85% of the sample for 1.6 daily hours and those older, with a computer in the bedroom, with a higher number of computers in home, who view more television and play videogames were more likely to use the computer.

Conclusion

Immediate and comprehensive actions are needed in order to diminish time spent at the television, videogames, and computer.

Trends in child overweight rates and energy intake in France from 1999 to 2007: relationships with socioeconomic status

Our objectives were (i) to assess the current prevalence of childhood overweight (including obesity) (OWOB) in France and its relationship with comprehensive socioeconomic status (SES) indicators and (ii) to examine trends in OWOB prevalence and changes in energy intake (EI) and sedentary behavior (SED) based on the previous INCA 1 (Individuelle Nationale des Consommations Alimentaires) data (1998-1999). A representative sample of children aged 3-14 (n = 1,030) was taken from the 2006-2007 cross-sectional INCA 2 food consumption survey. Weight and height were measured. The prevalence of OWOB was estimated according to the IOTF (International Obesity Task Force) definition. Average daily EI was evaluated using a 7-day food record. SED (screen time) and SES were reported by answering questionnaires. SES indicators included the occupation and level of education of the head of the household (HH), and variables describing household wealth. Composite indices of SES were computed by correspondence analysis, and relationships with OWOB were explored by logistic regression analysis. In total, 14.5% (95% CI: 12.1-17.0) of the children were OWOB. All SES indicators were inversely correlated to OWOB. Average EI was equal to 1,739 kcal/day. Daily, children spent 113.5 min watching television, and 38.5 min playing video games or using a computer. Compared to the INCA 1 study, OWOB prevalence was not significantly different, EI was lower, and SED was higher. These trends were the same across all occupational categories of heads of household. Although overall rates of childhood OWOB are currently stabilizing, no change was observed in the strong inverse socioeconomic gradient of OWOB between the two studies.

Time spent playing outdoors after school and its relationship with independent mobility: a cross-sectional survey of children aged 10-12 years in Sydney, Australia

BACKGROUND

Time spent outdoors is positively associated with physical activity and has been suggested as a proxy for physical activity of children. The role of children's independence in physical activity and time spent outdoors is less understood. This study aimed to assess how much time children spent playing outdoors after school, and to explore the relationship between outdoor play and independence among children aged 10-12 years.

METHOD

Children recorded how much time they spent playing outdoors or watching TV/videos or playing computer games after school using a five-day diary, and also reported whether they were allowed to walk on their own in their neighbourhood as an indicator of their independent mobility. Parents were surveyed on family demographics and perception of neighbourhood safety. The surveys were conducted in late 2006 as part of the Central Sydney Walk to School program which involved 1975 children and their parents from 24 primary schools. Factors associated with time spent playing outdoors were determined by logistic regression modelling.

RESULTS

Thirty-seven per cent of children spent less than half an hour a day playing outdoors after school, and 43% spent more than 2 hours a day watching TV, videos or playing computer games. Forty-eight per cent of children were allowed to walk on their own near where they lived. Children's independent mobility was significantly associated with outdoor play after adjusting for other confounders. Compared with those who were never allowed to walk on their own near where they lived, students who were allowed to walk on their own were significantly more likely to spend more than half an hour a day playing outdoors after school with an adjusted odds ratio of 2.6, 95% CI 1.84-3.58, P < 0.001.

CONCLUSION

The findings that a significant proportion of children spend less than half an hour a day playing outdoors after school and have excessive screen time have important implications for physical activity promotion and obesity prevention. The study also suggests that children's independent mobility should be considered in research and evaluation into children's play and physical activity. Environments that promote greater independent mobility in children may increase their physical activity levels and hence reduce their risk of overweight/obesity.

School meals in French secondary state schools with regard to the national recommendations

In 2001, a circular addressing both the composition of school meals and food safety issues was introduced in France to improve the nutrient composition of school meals and provided food-frequency guidelines to guarantee dietary balanced meals. The present study assesses the extent to which secondary state schools are familiar with and implement this circular. In 2005, a nationally representative sample of 1440 secondary state schools received a questionnaire on their catering service and the implementation of the circular's recommendations, and were requested to enclose all menus (lunches and dinners) served over 1 month. Menu analysis shows that progress is still required to achieve a meal composition in accordance with the food-group frequency guidelines appended to the circular. Some recommendations are followed by most of the schools, such as limiting high-fat products and providing plenty of raw fruits and vegetables, cooked vegetables and starchy foods. Other guidelines should be implemented further, especially with regard to the nutritional quality of main courses and dairy products, which are met by less than a third and a half of schools, respectively. Specific efforts are necessary for evening meals to ensure that the nutritional requirements of boarders are covered. Some recommendations, such as the food purchasing manager being trained in nutrition (38 % of schools) and the involvement of dietetic expertise when designing meals (6 %), seem to be linked to better dietary balance of meals. Implementation of the circular must therefore be promoted in schools and may require stronger regulatory nutrition standards and better cooperation between schools.

Are eating occasions and their energy content related to child overweight and socioeconomic status?

The objectives of this study were: (i) to assess the relationships between childhood overweight (OW) and four eating behaviors: daily eating frequency, and the relative contribution of breakfast, main meals (lunch and dinner), and snacks to total daily energy intake (EI); (ii) to explore whether these eating behaviors are involved in the negative association between socioeconomic status (SES) and OW. A representative sample of French children aged 3-11 years (n = 748) was taken from the 1998-1999 cross-sectional French INCA1 (Enquête Individuelle et Nationale sur les Consommations Alimentaires) food consumption survey. Food intake was reported in a 7-day food record, and SES, physical activity, sedentary behavior (SED), weight, and height were reported by answering face-to-face questionnaires. After adjusting for EI, physical activity, and SED, OW was positively associated with the contribution of the main meals to EI (P = 0.03), not significantly associated with the contribution of breakfast to EI, and inversely correlated to the number of eating episodes (P = 0.009) and to the contribution of snacking episodes to EI (P = 0.007). Our data suggest that a combination of more frequent intake occasions and lower contribution of the main meals to total daily EI is associated with a smaller risk of OW in children. However, eating frequency was the only eating behavior that played a slight mediation role (contributing approximately 8%) in the inverse relationship between SES and OW.

Foot morphology of normal, underweight and overweight children

OBJECTIVE

Due to the fact that there is a global increase in obesity, knowledge about the impact of obesity on the development of a child's foot is of great importance for orthopaedic and paediatric physicians with regard to prevention, clinical treatment and management. Therefore, the purpose of this study was to investigate the influence of body mass on the development of a child's foot based on a foot type classification.

METHODS

The feet of 1450 boys and 1437 girls aged 2-14 years were measured using a three-dimensional (3D) foot scanner (Pedus, Human Solutions Inc., Germany) in a bipedal upright position. Twelve relevant 3D foot measures were recorded, as well as the children's age, gender, height and mass. Factor analysis of principal components was used to obtain a smaller number of independent and standardized variables. The variables were used for cluster analysis to classify the children's feet.

RESULTS

Five foot types were identified: flat, robust, slender, short and long feet. There were significant differences among foot types with respect to the children's body mass index. Normal weight children displayed an almost equal distribution of all foot types throughout childhood. Flat and robust feet were more common in overweight children, whereas underweight children showed more slender and long feet.

CONCLUSION

The influence of excess, as well as deficient mass could be verified for the comprehensive foot morphology based on a foot type classification. Subsequently, foot discomfort as a result of various musculoskeletal disorders may develop. In turn, this might keep the children from being active and therefore reinforce the risk of developing obesity. However, there is still a lack of information regarding these relationships, which needs to be determined. This knowledge may help prevent orthopaedic foot problems and injuries.

Sedentary behaviour and obesity development in children and adolescents

Sedentary lifestyle patterns in children and adolescents, i.e. playing digital games, using computers and especially watching television, have been associated with obesity. However, not all sedentary behaviour has shown the same relevance to, and relationship with, obesity. Therefore, we conducted a review including published studies found in PubMed and other medical journals, dated between January 1990 and April 2007. The ages of the children and adolescents who were the object of the study ranged between 2 and 18 years. For the purpose of this paper, we selected cross-sectional, longitudinal and intervention studies. Sufficient evidence exists to recommend setting a limit to the time spent watching TV, especially for younger children. However, video games and computers do not represent such a high risk compared to watching TV, when they do not replace physical activity too much. In fact, there is no evidence to suggest that sedentary behaviour displaces physical activity levels. Mechanisms that explain the link between sedentariness and obesity are also discussed. Finally, future studies should take into account important mediators such as socioeconomic status and family structure.

Promotion of physical activity in children

PURPOSE OF REVIEW

Promotion of physical activity continues to be recommended as an essential component of obesity treatment and prevention interventions. This review explores recent updates in the area of physical activity promotion and its impact on the physical and mental health consequences of childhood obesity.

RECENT FINDINGS

Despite the availability of opportunities for physical activity in the school environment, namely recess and physical education classes, students do not appear to be meeting activity recommendations at school alone. Access to neighborhood parks may increase levels of physical activity and reduce time spent in sedentary behaviors at home. Less time spent watching television and in other sedentary behaviors such as playing videogames may contribute to higher rates of physical activity. Frequency of physical activity also appears to be related to improved mental health status, although the direction of this relationship warrants further exploration.

SUMMARY

Physical activity is an evidence-based intervention that offers benefits to both physical and mental health. Pediatric health care providers are encouraged to engage in discussions with patients and families on the topic of physical activity and to assist them in finding ways to incorporate activity into daily life.

Dietary and physical activity patterns in French children are related to overweight and socioeconomic status

Sedentary behavior (SED) has already been identified as a risk factor of childhood overweight (OW) but less is known about the dietary patterns related to adiposity. Our objective was to investigate if lifestyle patterns combining overall diet and physical activity were associated with childhood OW and if they were involved in the reverse association between socioeconomic status (SES) and OW. Dietary intake was assessed using a 7-d food record in 748 French children aged 3-11 y from the 1998-1999 cross-sectional French Enquête Individuelle et Nationale sur les Consommations Alimentaires national food consumption survey. Weight and height, leisure time physical activity, SED (television viewing), and SES were reported by parents or children by answering questionnaires. Scores for lifestyle patterns were assessed with factor analysis and their relationship with OW was explored by logistic regression analysis. Two similar lifestyle patterns were identified in children aged 3-6 y and 7-11 y: "snacking and sedentary" and "varied food and physically active." The snacking and sedentary pattern was positively associated with OW in the youngest children (P-trend = 0.0161) and partly mediated the negative association of SES to OW. The varied food and physically active pattern was inversely correlated with OW in the eldest children only (P-trend = 0.0401). A third pattern called "big eaters at main meals" was derived in children aged 7-11 y and was positively correlated with OW (P-trend = 0.0165). From a public health perspective, the combinations of identifiable dietary and physical activity behaviors may be useful as a basis for recommendations on preventing OW.

Effect of physical activity intervention on body composition in young children: influence of body mass index status and gender

Aim

To fight overweight and obesity in childhood, this study proposes an additional physical activity (PA) in young children aged 6–10 years. The objective was to evaluate the effect of school-based PA on the body composition according to body mass index (BMI) categories (nonobese vs. obese) and gender.

Methods

This 6-month study examined the effect of this intervention on body composition in 425 children in 14 primary schools (2 weekly PA sessions of 1 h each) compared to 5 control schools. Adiposity indices were evaluated or calculated: BMI, BMI z-score, waist circumference, sum of skinfolds and fat-free mass.

Results

No difference in the prevalence of obesity and anthropometric characteristics was found between the intervention and control groups at baseline. In girls, PA intervention had significant effect on all anthropometric variables (p < 0.05 to p < 0.001), except on BMI. In contrast, in boys only BMI z-score (p < 0.001) and fat-free mass (p < 0.001) were affected.

Conclusions

Six months of preventive PA intervention offer an effective means to improve body composition in obese children. The pattern of response related to PA was similar between girls and boys. In contrast, the pattern was different according to BMI category, with a higher response in obese than nonobese children.