High prevalence of obesity in low income and multiethnic schoolchildren: a diet and physical activity assessment

What is a "high" prevalence of obesity? Two rapid reviews and a proposed set of thresholds for classifying prevalence levels

Categories such as "low" and "high" have been used for several decades to describe the prevalence of stunting and wasting in populations of children aged under 5 years. They provide support for public health risk assessment and policy-making, including alerting health departments and aid agencies to national trends and local needs. In the light of the need for monitoring progress to meet globally agreed targets for overweight and obesity, the classification of their prevalence will be a valuable to aid in policy development, to target resources, and to promote public health interventions. This paper reviews the current use of categories to describe obesity prevalence in policy, advocacy, and research literature. Where prevalence categories have been formally proposed, this paper compares their application on large-scale datasets. The paper then develops a set of recommended threshold values to classify prevalence levels for overweight and obesity among children under age 5 years, children aged 5-19 years, and adults.

Agreement between parent and child report of physical activity, sedentary and dietary behaviours in 9-12-year-old children and associations with children's weight status

BACKGROUND

To date, population based surveys aimed at gaining insight in health related behaviour of children have often used either child self-reports or parent proxy reports. It remains unclear however, if surveys using different sources of information from either parents or children are comparable. In addition, (over)weight status of children can lead to under- and over reporting by parents and children as a result of social desirability bias. We aimed at gaining insight in the level of agreement between parents and child reports regarding aspects of certain dietary, physical activity and sedentary behaviours, and whether there are differences in agreement between parents and child reports in healthy-weight and overweight children.

METHODS

Weighted kappa was used to determine the level of agreement between child and parent reports on health-related behaviour in 1998 parent-child dyads. We also stratified for weight status of the children. Information on children's health related behaviours was obtained by parental and children's questionnaires, and children's height and weight were measured. Associations between children's weight status and children reporting less, reporting more and reporting the same amount of health behaviour as their parents were investigated with multinomial logistic regression analysis.

RESULTS

The Cohen's kappa coefficients ranged from almost perfect agreement for the variable means of transportation, fair for the variables breakfast consumption and frequency of outside play to slight for the variables duration of outside play, frequency and duration of TV/DVD viewing and family dinner. Overweight children were significantly more likely to report less breakfast consumption (OR = 2.6 (95% CI: 1.3 - 5.1)) and lower frequency of outside play than their parents (OR = 1.8 (95% CI: 1.1 - 2.9)).

CONCLUSION

There can be considerable disagreement between the health related behaviours of children as reported by parents or the children themselves. Based on the present study, it cannot be concluded whether parents' or children's reports are more accurate. For future studies, social desirability and recall bias would be best demonstrated in a validation study comparing child and parent self-reports with more objective measures of physical activity and food intake.

High rates of the metabolic syndrome in a First Nations Community in western Canada: prevalence and determinants in adults and children

OBJECTIVES

Increasing type 2 diabetes in Aboriginal communities across North America raises concerns about metabolic syndrome in these populations. Some prevalence information for American Indians exists, but little has been available for Canada's First Nations.

STUDY DESIGN

We screened 60% of the eligible population of a single First Nation in Alberta for diabetes, pre-diabetes, cardiovascular risk, and metabolic syndrome.

METHODS

NCEP/ATP III and IDF criteria were used to identify metabolic syndrome in participants aged > or = 18; modified NCEP/ATP III criteria were used for participants aged < 18. Logistic regression identified factors associated with the metabolic syndrome.

RESULTS

297 individuals were screened (176 adults, 84 children/adolescents, with complete data). 52.3% of adults had metabolic syndrome using NCEP/ATP III criteria, and 50% using IDF criteria. 40.5% of individuals aged < 18 had the condition. Waist circumference was the most prevalent correlate. Bivariate analysis suggested that age, BMI, weight, Alc, LDL-C, ADA risk score and activity pattern were associated with metabolic syndrome.

CONCLUSIONS

Our data represent the first available for Western Cree and are consistent with prevalence reported for Aboriginal populations in Ontario and Manitoba. High rates of obesity, pre-diabetes and metabolic syndrome for participants aged < 18 raise concerns about future prevalence of diabetes and cardiovascular disease.

Opportunities for Student Physical Activity in Elementary Schools: A Cross-Sectional Survey of Frequency and Correlates

The objectives of this study were to describe opportunities for student physical activity (PA) in elementary schools and to identify factors in the school environment associated with higher PA opportunity. Self-report questionnaires were completed by school principals and physical education teachers in 277 schools (88% response) in metropolitan Montreal. Correlates of opportunity were identified using ordinal logistic regression. There was substantial variation in PA opportunities between schools. Higher opportunity was associated with role modeling of PA by school principals, their interest in increasing PA through links to the municipality, adequate financial and human resources, access to school sports facilities, adequate space for storing student sports equipment, and suburban location. There is both the need and the potential for intervention to increase PAopportunities in elementary schools. Addressing barriers related to resources and access to sports facilities may help reduce disparities between schools in opportunities for students to engage in PA.

Influence of Parenting Practices on Eating Behaviors of Early Adolescents during Independent Eating Occasions: Implications for Obesity Prevention

Among early adolescents (10-14 years), poor diet quality along with physical inactivity can contribute to an increased risk of obesity and associated biomarkers for chronic disease. Approximately one-third of United States (USA) children in this age group are overweight or obese. Therefore, attention to factors affecting dietary intake as one of the primary contributors to obesity is important. Early adolescents consume foods and beverages during eating occasions that occur with and without parental supervision. Parents may influence eating behaviors of early adolescents during eating occasions when they are present or during independent eating occasions by engaging in practices that affect availability of foods and beverages, and through perceived normative beliefs and expectations for intake. Therefore, the purpose of this article was to describe the influence of parenting practices on eating behaviors in general and when specifically applied to independent eating occasions of early adolescents. This information may be helpful to inform parenting interventions targeting obesity prevention among early adolescents focusing on independent eating occasions.

Associations between socio-economic status and school-day dietary intake in a sample of grade 5–8 students in Vancouver, Canada

Objective

To examine associations between students’ socio-economic status (SES) and school-day dietary intake, and the roles of parents and peers in shaping these associations.

Design

A cross-sectional survey measured school-day intake of vegetables, whole grains, low-fat milk, packaged snack foods and sugar-sweetened beverages. Logistic regression models examined associations between SES (parental education and food insecurity status) and dietary outcomes during or en route to or from school, and examined whether peer modelling or parental norms potentially mediated the associations between SES and dietary outcomes.

Setting

Twenty-six public schools in Vancouver, Canada in 2012.

Subjects

Nine hundred and fifty students in grades 5–8.

Results

Students whose parents completed some college, compared with those completing high school or less, were significantly more likely to consume vegetables daily (unadjusted OR=1·85; 95 % CI 1·06, 3·22) and students whose parents completed college or university were significantly less likely to consume sugar-sweetened beverages daily (unadjusted OR=0·67; 95 % CI 0·47, 0·94). Food secure students were also significantly less likely to consume sugar-sweetened beverages daily compared with food insecure students (unadjusted OR=0·52; 95 % CI 0·29, 0·92). Parental norms, but not peer modelling, emerged as a potential mediator of the association between SES and vegetable intake. SES was not significantly associated with the remaining dietary outcomes.

Conclusions

Higher SES was significantly associated with two of five school-day dietary outcomes and predicted higher likelihood of daily nutritious food choices at school. The present study suggests that there is room for improvement in school-day dietary quality for students from all SES backgrounds in Vancouver.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18

BACKGROUND

The World Health Organization (WHO) estimates that 1.9 million deaths worldwide are attributable to physical inactivity and at least 2.6 million deaths are a result of being overweight or obese. In addition, WHO estimates that physical inactivity causes 10% to 16% of cases each of breast cancer, colon, and rectal cancers as well as type 2 diabetes, and 22% of coronary heart disease and the burden of these and other chronic diseases has rapidly increased in recent decades.

OBJECTIVES

The purpose of this systematic review was to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents.

SEARCH METHODS

The search strategy included searching several databases to October 2011. In addition, reference lists of included articles and background papers were reviewed for potentially relevant studies, as well as references from relevant Cochrane reviews. Primary authors of included studies were contacted as needed for additional information.

SELECTION CRITERIA

To be included, the intervention had to be relevant to public health practice (focused on health promotion activities), not conducted by physicians, implemented, facilitated, or promoted by staff in local public health units, implemented in a school setting and aimed at increasing physical activity, included all school-attending children, and be implemented for a minimum of 12 weeks. In addition, the review was limited to randomized controlled trials and those that reported on outcomes for children and adolescents (aged 6 to 18 years). Primary outcomes included: rates of moderate to vigorous physical activity during the school day, time engaged in moderate to vigorous physical activity during the school day, and time spent watching television. Secondary outcomes related to physical health status measures including: systolic and diastolic blood pressure, blood cholesterol, body mass index (BMI), maximal oxygen uptake (VO2max), and pulse rate.

DATA COLLECTION AND ANALYSIS

Standardized tools were used by two independent reviewers to assess each study for relevance and for data extraction. In addition, each study was assessed for risk of bias as specified in the Cochrane Handbook for Systematic Reviews of Interventions. Where discrepancies existed, discussion occurred until consensus was reached. The results were summarized narratively due to wide variations in the populations, interventions evaluated, and outcomes measured.

MAIN RESULTS

In the original review, 13,841 records were identified and screened, 302 studies were assessed for eligibility, and 26 studies were included in the review. There was some evidence that school-based physical activity interventions had a positive impact on four of the nine outcome measures. Specifically positive effects were observed for duration of physical activity, television viewing, VO2 max, and blood cholesterol. Generally, school-based interventions had little effect on physical activity rates, systolic and diastolic blood pressure, BMI, and pulse rate. At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity resulted in positive effects.In this update, given the addition of three new inclusion criteria (randomized design, all school-attending children invited to participate, minimum 12-week intervention) 12 of the original 26 studies were excluded. In addition, studies published between July 2007 and October 2011 evaluating the effectiveness of school-based physical interventions were identified and if relevant included. In total an additional 2378 titles were screened of which 285 unique studies were deemed potentially relevant. Of those 30 met all relevance criteria and have been included in this update. This update includes 44 studies and represents complete data for 36,593 study participants. Duration of interventions ranged from 12 weeks to six years.Generally, the majority of studies included in this update, despite being randomized controlled trials, are, at a minimum, at moderate risk of bias. The results therefore must be interpreted with caution. Few changes in outcomes were observed in this update with the exception of blood cholesterol and physical activity rates. For example blood cholesterol was no longer positively impacted upon by school-based physical activity interventions. However, there was some evidence to suggest that school-based physical activity interventions led to an improvement in the proportion of children who engaged in moderate to vigorous physical activity during school hours (odds ratio (OR) 2.74, 95% confidence interval (CI), 2.01 to 3.75). Improvements in physical activity rates were not observed in the original review. Children and adolescents exposed to the intervention also spent more time engaged in moderate to vigorous physical activity (with results across studies ranging from five to 45 min more), spent less time watching television (results range from five to 60 min less per day), and had improved VO2max (results across studies ranged from 1.6 to 3.7 mL/kg per min). However, the overall conclusions of this update do not differ significantly from those reported in the original review.

AUTHORS' CONCLUSIONS

The evidence suggests the ongoing implementation of school-based physical activity interventions at this time, given the positive effects on behavior and one physical health status measure. However, given these studies are at a minimum of moderate risk of bias, and the magnitude of effect is generally small, these results should be interpreted cautiously. Additional research on the long-term impact of these interventions is needed.

Associations of youth and parent weight status with reported versus predicted daily energy intake and hemoglobin A1c in youth with type 1 diabetes mellitus

BACKGROUND

The epidemic of overweight/obesity affects youth with type 1 diabetes mellitus (T1DM) and their families. In youth with T1DM and their parents, we examined weight status with reported and expected energy intake and with youth hemoglobin A1c (HbA1c).

METHODS

In 243 youth (48% female, 13 ± 3 years) and their parents (84% female, 45 ± 6 years), we assessed body mass index (BMI), prevalence of overweight/obesity, reported energy intake (REI), and youth glycemic control (HbA1c). The REI was compared with predicted daily energy requirements (DER; based on age, weight, sex, and physical activity).

RESULTS

Youth had diabetes duration of 6.3 ± 3.4 years and HbA1c of 8.5% ± 1.3%; 69% used insulin pump therapy. Overweight and obesity affected 23% and 11% of youth and 30% and 24% of parents, respectively. Youth and parent BMI (r = 0.38; p < .001) and weight status (overweight/obese; p < .001) were significantly associated. The ratio of REI:DER was significantly lower in overweight/obese compared with underweight/normal weight parents (1.0 ± 0.4 versus 1.2 ± 0.5; p = .001) but did not differ among youth by weight status. Both youth and parent BMI were positively correlated with youth HbA1c (r = 0.14, p = .02; r = 0.16, p = .01, respectively). Hemoglobin A1c tended to be higher in obese than in overweight and normal weight youth (mean ± standard deviation [SD] 8.4 ± 1.4, 8.4 ± 1.3, and 8.8 ± 1.0, respectively; p = .06) and was significantly higher in youth whose parents were obese versus overweight or underweight/normal weight (mean ± SD 8.2 ± 1.2, 8.5 ± 1.4, and 8.9 ± 1.5, respectively; p < .001).

CONCLUSIONS

Similar to the general population, overweight and obesity are prevalent among families of youth with T1DM. Weight status appears to influence self-REI in parents and glycemic control in youth with T1DM, suggesting the need for family-based dietary interventions.

Physical activity fluctuations and body fat during adolescence

OBJECTIVE

The objective of the study was to test the hypothesis that greater fluctuations in physical activity lead to greater increases in body fat during adolescence.

METHODS

Seven hundred fifty-six adolescents in Montreal, Canada, aged 12-13 years at baseline, completed a 7-d physical activity recall questionnaire every 3 months over 5 years. Body mass index (BMI), waist circumference, and triceps and subscapular skinfold thickness were measured at baseline and at the end of follow-up. Subject-specific linear regressions, expressing physical activity as a function of time, were fitted and physical activity fluctuation scores were obtained by averaging the absolute values of regression residuals. The association between body fat after 5 years and the physical activity fluctuation score was assessed in linear regressions adjusting for baseline body fat, average number of physical activity sessions per week, diet and sociodemographic variables.

RESULTS

Among boys, there were statistically significant positive associations between physical activity fluctuation and BMI (β, 95% confidence interval: 0.12, 0.02-0.21) and triceps skinfold (0.40, 0.17-0.63). The associations with waist circumference or subscapular skinfold were not statistically significant (0.22, -0.04-0.49; 0.13, -0.05-0.32, respectively). In girls, there were statistically significant negative associations between physical activity fluctuation and BMI (-0.12, -0.20 to -0.03), waist circumference (-0.54, -0.91 to -0.17), subscapular skinfold (-0.41, -0.56 to -0.26) and triceps skinfold (-0.22, -0.38 to -0.05).

CONCLUSION

Physical activity fluctuations appear to affect body fat during adolescence. Sex-specific interventions may be needed given that greater physical activity fluctuations seem unfavourable for boys and beneficial for girls.

Nutrition needs assessment of young Special Olympics participants

BACKGROUND

Children with intellectual disability (ID) are at increased risk for obesity and nutrition-related health concerns, yet there is a paucity of data describing their nutrition status. The purpose of this study was to evaluate nutritional challenges of young participants (2?10 years of age) enrolled in Special Olympics Canada (SOC) programs.

METHOD

A validated nutrition screening tool was mailed to 52 parents/caregivers of participants across 18 SOC programs in British Columbia, Canada.

RESULTS

Of the 29 (55.8%) questionnaires returned, 62.1% scored as "high" nutrition risk. Nutrition concerns included feeding (84.2%), oral motor (57.9%), and dental problems (26.3%), food allergies/intolerances (26.3%), constipation (15.8%), anaemia (10.3%), and diarrhoea (5.3%). Body mass index (BMI) for age data classified 16.7% of participants as overweight/obese and 22.2% as underweight.

CONCLUSIONS

This study identifies some of the unique nutrition issues faced by children with ID. These data can help inform future ID health-related nutrition, prevention, and treatment programs.

Adolescents' food preferences in china: do household living arrangements matter?

Family circumstance has long been considered one important factor that shapes children's eating habits including preferences for particular foods. However, less scholarly efforts have been devoted to understanding children's food preferences in extended family households. Drawn on data from the China Health and Nutrition Survey (CHNS) 2006 (n = 662), this exploratory study compares food preferences of adolescents living in extended families with those residing in nuclear families. T-test results show that adolescents living in extended families (n = 202) had unhealthier food preferences compared with those living in nuclear families (n = 460). They showed more liking for fast food, salted snack food, and sugared drinks, and less liking for vegetables and fruits. Regression results present that controlling for other relevant variables, household structure was significantly associated with adolescents' food preferences (p < .01). These results, albeit exploratory, shed light on possible nutritional education and intervention in the cultural context of China.

Energy intake misreporting among children and adolescents: a literature review

While adults' energy intake misreporting is a well-documented phenomenon, relatively little is known about the nature and extent of misreporting among children and adolescents. Children's and adolescents' dietary reporting patterns are likely to be distinct because of their ongoing cognitive and social development. These developmental differences present unique challenges to aspects of dietary reporting, such as food knowledge, portion size estimation and response editing. This review of 28 articles describes energy intake misreporting among children and adolescents. Like adults, children and adolescents tended to underreport energy, with the largest biases observed with food records. Even when mean reported energy intake was close to its expected value, approximately half of all individuals were classified as misreporters, and overreporting appeared to be more common than it is among adults. Associations between numerous characteristics and misreporting were explored in the literature, with the most consistent findings for age and adiposity. Two predictors for adults, gender and social desirability, were not consistent factors among children and adolescents. The review concludes by highlighting knowledge gaps and recommendations for future research and practice.

Teens and screens: the influence of screen time on adiposity in adolescents

The effect of screen time during secondary school on percent body fat was examined in a cohort of 744 Canadian adolescents aged 12-13 years at baseline. Participants completed self-reported questionnaires on television viewing and computer use in 19 survey cycles over 57 months from 1999 to 2005. Triceps skinfold thickness and subscapular skinfold thickness were measured in survey cycles 1 and 19. Four screen-time trajectory groups identified in growth mixture modeling included steady-low screen time (73% of the sample), steady-high (10%), increasers (9%), and decreasers (8%). The effect of screen-time trajectory on percent body fat at survey cycle 19 was modeled in boys and girls separately by using linear regression, adjusting for baseline percent body fat and physical activity. Relative to that of steady-low screen-time trajectory group boys, percent body fat was 2.9 (95% confidence interval: 0.7, 5.0) and 2.4 (95% confidence interval: 0.5, 4.2) percentage units higher on average among "increasers" and "steady-high" trajectory group boys, respectively. There was no evidence that screen time has an effect on percent body fat in girls overall, although physical activity modified the association between screen time and percent body fat in both sexes. Efforts to prevent obesity in youth should emphasize reducing screen time.

Declines in physical activity and higher systolic blood pressure in adolescence

The authors examined the potential association between changes in the number of moderate-to-vigorous physical activity (MVPA) sessions per week, adiposity, and systolic blood pressure (SBP) during adolescence. SBP and anthropometric factors were assessed biannually (1999/2000, 2002, and 2004) in a cohort of 1,293 Canadian adolescents aged 12-13 years in 1999. Self-reported 7-day recall data on MVPA sessions >or=5 minutes in duration were collected every 3 months over the 5-year period. Estimates of initial level and rate of decline in number of MVPA sessions per week from individual growth models were used as predictors of SBP in linear regression models. A decline of 1 MVPA session per week with each year of age was associated with 0.29-mm Hg and 0.19-mm Hg higher SBPs in girls and boys, respectively, in early adolescence (ages 12.8-15.1 years) and 0.40-mm Hg and 0.18-mm Hg higher SBPs, respectively, in late adolescence (ages 15.2-17.0 years). The associations were not attenuated by changes in body mass index, waist circumference, or skinfold thickness in girls during late adolescence. Although weaker, associations were evident in boys during late adolescence, as well as in both girls and boys during early adolescence. These results support prevention of declines in MVPA during adolescence to prevent higher blood pressure in youth.

Effect of meal environment on diet quality rating

PURPOSE

Family meals have been associated with improved dietary quality in children and adolescents, and yet very little is known about family meals beyond their frequency. Specific aspects of the breakfast, lunch, and dinner meal environments were described and compared, and the associations with overall diet quality were investigated.

METHODS

Data on food intake and meal environments were obtained in northern Ontario, southern Ontario, and Nova Scotia grades six, seven, and eight classrooms over the 2005 to 2006 school year. Specific aspects of the meal environments described were where the meal was consumed, with whom participants consumed each meal, who prepared the meal, and where the food was originally purchased. Diet quality was assessed using the Canadian version of the Healthy Eating Index. Cluster K-means procedures were used to classify into groups observations about the four meal environment variables.

RESULTS

Three, eight, and six clusters of meal environments were identified for breakfast, lunch, and dinner, respectively. Diet quality was negatively associated with consuming/ purchasing meals outside the home, and with skipping breakfast, lunch, and/or dinner.

CONCLUSIONS

Results have immediate relevance for family-based and/or school programs and policies aimed at educating and feeding children and adolescents.

Family structure, nonresident father involvement, and adolescent eating patterns

PURPOSE

To examine the relationship between family structure, nonresident father involvement, and adolescent eating patterns.

METHODS

Analyses were performed on data from Waves 1 and 2 of the National Longitudinal Study of Adolescent Health (Wave 1, N = approximately 15,550; Wave 2, N = approximately 11,540), and a subsample of adolescents from each wave who had a nonresident father (Wave 1, N = approximately 3,745; Wave 2, N = 2,358). Multivariate regression provides estimates of the independent effects of family structure and nonresident father involvement on adolescent eating patterns while controlling for potentially confounding sociodemographic characteristics.

RESULTS

Compared with children in traditional households (i.e., two biological or adoptive parents), adolescents in nontraditional family households (single parent, step-parent, no parent) were more likely to display unhealthy eating habits such as skipping breakfast and lunch, eating fewer vegetables, consuming more fast food, and had less parental monitoring of meals. Nonresident father involvement was associated with an increased frequency of eating breakfast and lunch and increased consumption of vegetables (Wave 1) but did not affect adolescents' consumption of fast food. Child support was positively associated with the odds that adolescents would consume dinner.

CONCLUSIONS

Adolescents in living in nontraditional families were more likely than adolescents living with two biological/adoptive parents to display unhealthy eating habits. Nonresident father involvement was generally associated with healthier eating patterns. Health professionals should keep in mind that children's and adolescents' living arrangements can be complex and have the potential to affect what and how they eat.

When adolescents drop the ball: sustainability of physical activity in youth

BACKGROUND

A majority of youth do not attain the recommended levels of physical activity. To develop interventions that will be more efficient at enabling healthy levels of physical activity during adolescence, a better understanding is needed about which specific types of physical activity adolescents are more likely to sustain and when they tend to stop participating in each specific type of activity.

METHODS

From 1999 to 2005, 1276 adolescents, initially aged 12-13 years, completed a 7-day physical activity recall every 3 months during each of 5 years of secondary school. The prevalence of participation in each of 29 specific physical activities in each of Grades 7-11 was computed. Survival analyses were used to estimate when adolescents who reported each activity at baseline tended to discontinue the activity. All analyses were conducted in 2008.

RESULTS

The prevalence of participation in most activities declined over the 5 years; it did not increase for any activity. Within 2 years of baseline, the majority of adolescents discontinued participation in most activities in which they had reported participation at baseline. Sustained participation in a specific activity related both to its intensity (90%, 73%, and 40% of girls and 77%, 86%, and 60% of boys sustained participation in light-, moderate-, and vigorous-intensity activities, respectively) and its format (41% and 89% of girls and 69% and 90% of boys sustained participation in team and individual physical activities, respectively).

CONCLUSIONS

Participation in almost all physical activities declined during adolescence. The time of discontinuation varied across activity types. Promoting activities that attract and sustain secondary school students may improve physical activity levels throughout adolescence.

Participation in organised sports does not slow declines in physical activity during adolescence

Background

Among youth, participation in extracurricular physical activities at school and organised physical activities in the community is associated with higher physical activity levels. The objective was to determine if participation in organised physical activities during early adolescence protects against declines in physical activity levels during adolescence.

Methods

Every 3 months for 5 years, students initially in grade 7 (aged 12–13 years) completed a 7-day physical activity recall and provided data on the number and type of (extracurricular) physical activities organised at school and in the community in which they took part. To study rates of decline in physical activity, only adolescents who reported an average of ≥5 moderate-vigorous physical activity sessions per week in grade 7 (n = 1028) were retained for analyses. They were categorised as to whether or not they were involved in organised physical activities in grade 7. We used generalized estimating equation Poisson regression to compare the rate of decline in number of moderate-vigorous physical activity sessions per week during adolescence between initially physically active students who participated in organised physical activity in grade 7 and those who did not.

Results

In grade 7, about 87% of physically active adolescents reported taking part in at least one organised physical activity. Compared to active adolescents not involved in organised physical activities, baseline involvement in physical activity was 42% (95% CI 26–59%) higher among those involved in organised physical activity (mean number of moderate-vigorous physical activity sessions per week = 14.6 ± 13.1 vs 10.4 ± 9.0). Physical activity declined by 8% per year in both groups. Results were similar in analyses that examined the effect of school or community-based physical activities separately.

Conclusion

Although participation in organised physical activities during early adolescence is associated with more physical activity throughout secondary school, participation in such activities does not protect against declines in physical activity over time.

Self-reported dietary energy intake of normal weight, overweight and obese adolescents

Objective

The purpose of the present paper was to assess dietary energy reporting as a function of sex and weight status among Ontario and Alberta adolescents, using the ratio of energy intake (EI) to estimated BMR (BMRest).

Design

Data were collected using the FBQ, a validated web-based dietary assessment tool (including a 24 h dietary recall, FFQ, and food and physical activity behavioural questions). BMI was calculated from self-reported height and weight and participants were classified as normal weight, overweight or obese. BMR was calculated using the WHO equations (based on weight). Reporting status was identified using the ratio EI:BMRest.

Setting

Data were collected in public, Catholic and private schools in Ontario and Alberta, Canada.

Subjects

A total of 1917 (n876 male andn1041 female) students (n934 grade 9 andn984 grade 10) participated.

Results

The mean EI:BMRestratio across all participants was 1·4 (sd0·6), providing evidence of under-reporting for the total sample. Females under-reported more than males (t= 6·27,P< 0·001), and under-reporting increased with increasing weight status for both males (F= 33·21,P< 0·001) and females (F= 14·28,P< 0·001). After removing those who reported eating less to lose weight, the EI:BMRestwas 1·56 (sd0·6) for males and 1·4 (sd0·6) for females.

Conclusion

The present study highlights methodological challenges associated with self-reported dietary data. Systematic differences in under-reporting of dietary intake by gender and weight status were observed using a web-based survey, similar to observations made using paper-based 24 h recalls and dietitian interviews.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6-18

BACKGROUND

The World Health Organization estimates that 1.9 million deaths worldwide are attributable to physical inactivity. Chronic diseases associated with physical inactivity include cancer, diabetes and coronary heart disease.

OBJECTIVES

The purpose of this systematic review is to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents.

SEARCH STRATEGY

The search strategy included searching several databases. In addition, reference lists of included articles and background papers were reviewed for potentially relevant studies, as well as references from relevant Cochrane reviews. Primary authors of included studies were contacted as needed for additional information.

SELECTION CRITERIA

To be included, the intervention had to be relevant to public health practice, implemented, facilitated, or promoted by staff in local public health units, implemented in a school setting and aimed at increasing physical activity, report on outcomes for children and adolescents (aged 6 to 18 years), and use a prospective design with a control group.

DATA COLLECTION AND ANALYSIS

Standardized tools were used by two independent reviewers to rate each study's methodological quality and for data extraction. Where discrepancies existed discussion occurred until consensus was reached. The results were summarized narratively due to wide variations in the populations, interventions evaluated and outcomes measured.

MAIN RESULTS

13,841 titles were identified and screened and 482 articles were retrieved. Multiple publications on the same project were combined and counted as one project, resulting in 395 distinct project accounts (studies). Of the 395 studies 104 were deemed relevant and of those, four were assessed as having strong methodological quality, 22 were of moderate quality and 78 were considered weak. In total 26 studies were included in the review. There is good evidence that school-based physical activity interventions have a positive impact on four of the nine outcome measures. Specifically positive effects were observed for duration of physical activity, television viewing, VO2 max, and blood cholesterol. Generally school-based interventions had no effect on leisure time physical activity rates, systolic and diastolic blood pressure, body mass index, and pulse rate. At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity result in positive effects.

AUTHORS' CONCLUSIONS

Given that there are no harmful effects and that there is some evidence of positive effects on lifestyle behaviours and physical health status measures, ongoing physical activity promotion in schools is recommended at this time.

Food consumption patterns in elementary school children

PURPOSE

Food consumption was investigated in children attending three elementary schools in urban Hamilton, Ontario.

METHODS

Dietary data were collected from 92 children in grades 2 to 4 through 24-hour dietary recalls (39% participation rate). Servings of four food groups were compared with recommended daily servings in Canada's Food Guide.

RESULTS

The majority of students did not consume the recommended five daily servings of vegetables and fruit. On average, they consumed a high number of servings of "other foods," which were not included in the four food groups. More than 50% of the students did not consume the recommended daily servings of milk products, and only a small proportion (21%) drank milk during school lunch.

CONCLUSIONS

We recommend that primary school educators promote the consumption of vegetables and fruits and milk products at school, either through healthy snack programs or educational programs.

Does social class predict diet quality?

A large body of epidemiologic data show that diet quality follows a socioeconomic gradient. Whereas higher-quality diets are associated with greater affluence, energy-dense diets that are nutrient-poor are preferentially consumed by persons of lower socioeconomic status (SES) and of more limited economic means. As this review demonstrates, whole grains, lean meats, fish, low-fat dairy products, and fresh vegetables and fruit are more likely to be consumed by groups of higher SES. In contrast, the consumption of refined grains and added fats has been associated with lower SES. Although micronutrient intake and, hence, diet quality are affected by SES, little evidence indicates that SES affects either total energy intakes or the macronutrient composition of the diet. The observed associations between SES variables and diet-quality measures can be explained by a variety of potentially causal mechanisms. The disparity in energy costs ($/MJ) between energy-dense and nutrient-dense foods is one such mechanism; easy physical access to low-cost energy-dense foods is another. If higher SES is a causal determinant of diet quality, then the reported associations between diet quality and better health, found in so many epidemiologic studies, may have been confounded by unobserved indexes of social class. Conversely, if limited economic resources are causally linked to low-quality diets, some current strategies for health promotion, based on recommending high-cost foods to low-income people, may prove to be wholly ineffective. Exploring the possible causal relations between SES and diet quality is the purpose of this review.

Does cigarette use influence adiposity or height in adolescence?

PURPOSE

To study the effect of cigarette use on height and adiposity in adolescents.

METHODS

Data on cigarette use were collected every 3 months for 5 years from adolescents initially 12-13 years of age. Height, weight, and triceps skinfold thickness were measured in survey cycles 1, 12, and 19. Multivariate linear regression models were fitted to estimate the association between cigarette use and the anthropometric measures in a dataset that pooled data over two time periods, from survey cycles 1-12 and from survey cycles 12-19.

RESULTS

Data were available for 451 boys and 478 girls. Seven percent of boys and 14% of girls smoked > or =30 cigarettes per month on average during the first time period; 9% of boys and 18% of girls smoked > or =30 cigarettes per month on average during the second time period. In boys, a 100-cigarette per month increment in cigarette use over the preceding 2.5 years was independently associated with lower body mass index (-0.4 kg/m(2)) and shorter height (-0.7 cm). In girls, cigarette use was not associated with height or adiposity.

CONCLUSIONS

While there was no relation in girls, cigarette use appears to decrease body mass index and height in boys. Young girls may be less likely to take up cigarette smoking if tobacco control messages emphasize that cigarette use may not be associated with reduced weight in adolescent females.

Gender differences in growth and nutrition in a sample of rural ontario schoolchildren

This paper reports findings of a cross-sectional study of the growth and nutrition of children living in rural Ontario, Canada. The objectives of the research were threefold: (1) to obtain data on obesity prevalence and nutrient intake in a sample of rural Canadian schoolchildren, (2) to compare findings with rural and national-level data on obesity prevalence and nutrient intake, and (3) to provide data to school board and public health agencies planning and implementing nutrition policy and programs to this population. Measures of height and weight were obtained for 504 children ages 7-13 years. Height for age and body mass index scores were calculated and compared with 2000 data from the Centers for Disease Control (Kuczmarski et al. [2002]: Vital Health Stat 246:1-190). Weekday 24-h dietary recall was conducted on a subsample of 352 children and the results compared with Canada's Food Guide (Health Canada,1997) and dietary reference data from the US Institute of Medicine (2000). Prevalence of overweight and obesity were high in this sample, with 17.7% of children classified as overweight and 10.9% of children classified as obese. Fifteen percent of boys were classified as obese, compared to 6.8% of girls. Boys consumed significantly more servings from the grain and meat food groups than girls. While mean daily intake of fiber and micronutrients was significantly low for both boys and girls, there were significant gender differences in nutrient intake, with boys consuming greater energy, protein, carbohydrate, calcium, iron, phosphorus, and sodium than girls. A number of limitations are discussed, in particular issues arising from the use of Dietary Reference Intakes.

Bioavailable dietary iron is associated with hemoglobin concentration in Mexican preschool children

The objective of this study was to estimate the amount of bioavailable iron (FeBIO) in the diet of Mexican children aged 12-59 mo through the application of algorithms that use dietary variables and analyze the association between estimated FeBIO and hemoglobin (Hb) concentration. Data were analyzed for 919 children aged 12-59 mo old who participated in a national probabilistic survey on nutrition, in which a 24-h dietary recall was applied and Hb concentration was determined through the use of portable photometers. Dietary intakes were determined for total iron, heme and nonheme iron, vitamin C, phytates, and meat (red meat, poultry, and fish). Using these dietary variables and distinct scenarios on body iron reserves, we used algorithms to estimate the amount of FeBIO in the diet. Linear regression models were adjusted to evaluate the association between FeBIO and Hb. The mean iron intake was 6.2 +/- 4.4 mg/d and the mean estimated FeBIO ranged between 0.14 and 0.37 mg/d depending on different assumptions about iron reserves, representing 2.7-6.1% of total iron intake. The Hb concentration, adjusted for altitude and presence of diarrhea, was positively associated with FeBIO in children 12-23 mo old (P < 0.05) but not in children 24-59 mo old. The estimated FeBIO is low in relation to physiological requirements and is compatible with existing high iron deficiency prevalence rates in Mexico. Although Hb is not a specific indicator of iron status, it was significantly associated with FeBIO.

Regular sugar-sweetened beverage consumption between meals increases risk of overweight among preschool-aged children

OBJECTIVE

To examine the relationship between consumption of sugar-sweetened beverages (eg, nondiet carbonated drinks and fruit drinks) and the prevalence of overweight among preschool-aged children living in Canada.

DESIGN

Data come from the Longitudinal Study of Child Development in Québec (1998-2002).

SUBJECTS/SETTING

A representative sample (n=2,103) of children born in 1998 in Québec, Canada. A total of 1,944 children (still representative of the same-age children in this population) remaining at 4 to 5 years in 2002 participated in the nutrition study.

STATISTICAL ANALYSES PERFORMED

Data were collected via 24-hour dietary recall interview. Frequency of sugar-sweetened beverage consumption between meals at age 2.5, 3.5, and 4.5 years was recorded and children's height and weight were measured. Multivariate regression analysis was done with Statistical Analysis System software. Weighted data were adjusted for within-child variability and significance level was set at 5%.

RESULTS

Overall, 6.9% of children who were nonconsumers of sugar-sweetened beverages between meals between the ages of 2.5 to 4.5 years were overweight at 4.5 years, compared to 15.4% of regular consumers (four to six times or more per week) at ages 2.5 years, 3.5 years, and 4.5 years. According to multivariate analysis, sugar-sweetened beverage consumption between meals more than doubles the odds of being overweight when other important factors are considered in multivariate analysis. Children from families with insufficient income who consume sugar-sweetened beverages regularly between the ages of 2.5 and 4.5 years are more than three times more likely to be overweight at age 4.5 years compared to nonconsuming children from sufficient income households.

CONCLUSIONS

Regular sugar-sweetened beverage consumption between meals may put some young children at a greater risk for overweight. Parents should limit the quantity of sweetened beverages consumed during preschool years because it may increase propensity to gain weight.

Nutrient intakes and food consumption patterns among Ontario students in grades six, seven, and eight

BACKGROUND

The increased prevalence of overweight in Canadian children has stimulated interest in their lifestyle behaviours. The purpose of this research was to investigate dietary intake and food behaviours of Ontario students in grades six, seven, and eight.

METHODS

Males and females from grades six to eight were recruited from a stratified random selection of schools from Ontario. Data were collected using the web-based "Food Behaviour Questionnaire", which included a 24-hour diet recall and food frequency questionnaire. Nutrients were analyzed using ESHA Food Processor and the 2001 Canadian Nutrient File database. Body Mass Index (BMI) was calculated based on self-reported weight and height, and classified according to the Centers for Disease Control BMI for age percentiles.

RESULTS

The sample included males (n = 315) and females (n = 346) in grades 6, 7, and 8 from 15 schools in Ontario. According to Canada's Food Guide to Healthy Eating (CFGHE), median intakes were below recommendations for all participants, with the exception of meat and alternatives. Participants consumed a median of 54%, 15%, 31%, 11%, and 8% of total energy from carbohydrates, protein, total fat, saturated fat, and added sugars, respectively. Participants consumed 25% of total energy from foods from the "other" food group (CFGHE). Males had higher intakes of energy, carbohydrates, fat, saturated fat, monounsaturated fat, protein, thiamine, niacin, iron, and zinc than females (all p < 0.05), and consumed more grain products servings (p < 0.05).

CONCLUSION

The high consumption of "other" foods, at the expense of nutrient-dense food groups, may ultimately be contributing to the increased weights in childhood and adolescence.

A concise overview of national nutrition action plans in the European Union Member States

Objective

This study presents an overview of national nutrition action plans in the member states of the European Union (EU), before its enlargement in 2004. In addition, their compliance with key recommendations of the World Health Organization, as documented in the First Action Plan for Food and Nutrition Policy and the Global Strategy on Diet, Physical Activity and Health, has tentatively been evaluated on the basis of the policy documents published.

Design

Literature review of publicly available policy national plans on nutrition and physical activity.

Setting

Member states of the EU before enlargement in May 2004.

Results

The development of national nutrition action plans is gaining momentum. Six of the 15 EU member states – namely, Sweden, Finland, Denmark, France, The Netherlands and the UK – have an operational nutrition policy and four of them have published an elaborated description of their nutrition policy in English. By the end of 2004, another four countries are expected to have their plan finalised. The available nutrition action plans generally seem to comply with international recommendations, although large variations are observed between the member states in terms of terminology, nutritional recommendations, institutional framework, nutritional scope, social groups targeted and monitoring and evaluation structures.

Conclusions

Although the importance of nutritional surveillance, a comprehensive approach to nutritional problems and stakeholder involvement is recognised by the action plans, the justification for it is vaguely described. This paper advocates for proper evaluation and documentation of interventions in public health nutrition and nutrition policies.

An integrative review of Canadian childhood obesity prevention programmes

To examine successful Canadian nursing and health promotion intervention programmes for childhood obesity prevention during gestation and infancy, an integrative review was performed of the literature from 1980 to September 2005. The following databases were used: PubMed; Cochrane Database of Systematic Reviews; Cochrane Controlled Trials Register; Database of Abstracts of Reviews of Effects; ACP Journal Club; MEDLINE; EMBASE; CINAHL; Web of Science; Scopus; Sociological Abstracts; Sport Discus; PsycInfo; ERIC and HealthStar. MeSH headings included: infancy (0-24 months), gestation, gestational diabetes, nutrition, prenatal care, pregnancy, health education, pregnancy outcome, dietary services with limits of Canadian, term birth. Of 2028 articles found, six Canadian childhood obesity prevention programmes implemented during gestation and/or infancy were found; three addressed gestational diabetes with five targeting low-income Canadian urban and/or Aboriginal populations. No intervention programmes specifically aimed to prevent childhood obesity during gestation or infancy. This paucity suggests that such a programme would be innovative and much needed in an effort to stem the alarming increase in obesity in children and adults. Any attempts either to develop new approaches or to replicate interventions used with obese adults or even older children need careful evaluation and pilot testing prior to sustained use within the perinatal period.

Obesity rates among rural Ontario schoolchildren

BACKGROUND

The majority of existing studies of obesity risk among Canadian children come from urban populations. The purpose of this study is to assess the prevalence of obesity in a sample of rural Ontario children.

METHODS

Measures of height and weight were obtained for 504 children attending seven public elementary schools in Grey and Bruce Counties, a predominantly rural area of Southern Ontario. Body mass index (BMI, or weight/height2) scores were calculated and compared with reference data from the Centers for Disease Control.

RESULTS

Rates of overweight and obesity were high in this sample, with 17.7% of children classified as overweight and 10.9% classified as obese. There was a significantly high prevalence of overweight for both boys (17.8%) and girls (17.5%) (Chi-square = 75.70, p < 0.001). However there was a significant gender difference in obesity prevalence: 15.0% of boys were obese, compared with 6.8% of girls (Mann-Whitney U = 29133.0, p > 0.05).

CONCLUSION

Findings indicate that among rural children--particularly boys--risk of overweight and obesity are at least as high as in their urban Canadian counterparts. There appear to be fewer girls than boys at the extreme high end of the distribution of BMI, which may indicate differences in the growth environment of rural boys and girls.

Family food insufficiency is related to overweight among preschoolers’

This paper studies the relationship between family food insufficiency and being overweight in a population-based cohort of preschool children (n=2103) using data from the Longitudinal Study of Child Development in Québec (1998-2002) (LSCDQ). Family food insufficiency status was derived when children were 1.5 years of age (from birth to 1.5 years) and at 4.5 years of age (from 3.5 to 4.5 years). Children's height and weight were measured at home at 4.5 years. Overweight was defined according to the US CDC sex- and age-specific growth charts and Cole's criteria. Statistical analyses were done with SAS (version 8.2). In multivariate analyses, mean body mass index (BMI) was higher for children from food insufficient families compared to children from food sufficient families, even when important factors associated with BMI, such as child's birth weight, parental BMI, maternal education, and family income sufficiency were considered. We did not report any gender effects in the multivariate analyses. The presence of family food insufficiency at some point during preschool years more than tripled (OR 3.4, 95% CI 1.5-7.6) the odds for obesity using the Cole criteria, and doubled (OR 2.0, 95% CI 1.1-3.6) the odds for overweight at 4.5 years using the CDC growth curves indicator. We observed an interaction between birth weight and family food insufficiency in relation to being overweight at 4.5 years. Low-birth-weight children living in a household that experienced food insufficiency during preschool years are at higher risk of overweight at 4.5 years. Given this important finding, supportive interventions targeting low-income and food insufficient families, including pregnant women, are recommended for preventing overweight and obesity among their children.

Effect of a Ban on Extracurricular Sports Activities by Secondary School Teachers on Physical Activity Levels of Adolescents: A Multilevel Analysis

To study the effect of a teachers' ban on supervising sports-related extracurricular physical activities (ECAs), levels of physical activity among 979 grade 7 students (mean age = 12.7 [0.5] years at baseline) were comparedduringand after the ban in seven schools that fully implementedthe ban, and three schools that did not implement the ban fully. On average, schools offered 18.0 ( SD = 5.1) ECAs during a no-ban school year. Students attending full implementation schools were significantly more likely than students in nonimplementation schoolsto be active after the banended(oddsratio forbeingactive = 1.89[95%confidenceinterval: 1.39,2.58]). They also increased the number of physical activities in which they participated (coefficient = 4.04; SE = 1.01). Ending a teachers' ban on sports-related ECAs was associated with increased involvement in physical activity among secondary school students.

Overweight Trends among Children Enrolled in the New York State Special Supplemental Nutrition Program for Women, Infants, and Children

The objective of this study is to describe overweight trends in a large, multiethnic, low-income population of preschool children by race/ethnicity and examine cohort changes in body mass index (BMI) distribution. Cross-sectional data were collected January 1 through March 31, every year, from 1989 to 2003. Subjects were children aged 2 to 4 years participating in the Special Supplemental Nutrition Program for Women, Infants, and Children in New York State. The prevalence of overweight (BMI > or =95th age- and sex-specific percentile of the 2000 Centers for Disease Control and Prevention growth charts) was calculated for each year. Least squares regression compared trends in prevalence by race/ethnicity. Changes in BMI distribution were assessed graphically. Overweight prevalence increased 33% (12% to 16%). Prevalence was highest for Hispanics and lowest for non-Hispanic whites. Rates of increase (0.28 percentage points per year) were the same for Hispanic, non-Hispanic black, and non-Hispanic white children. The BMI distribution shifted toward higher values for all children studied; for 3- and 4-year-old children, the difference increased as BMI increased, indicating that, in 2003, the heaviest children were considerably heavier than the heaviest children were in 1989.

Childhood obesity in Iraq: prevalence and possible risk factors

BACKGROUND

Childhood obesity is increasing in prevalence in developing countries. We conducted this study to assess the prevalence of overweight and obesity in primary school children age 7 to 13 years in central Iraq and to identify possible risk factors.

METHODS

The study was conducted in Babil governorate from October through March 2002. Eight thousand three hundred pupils (4100 girls and 4200 boys) randomly chosen primary schools were included in the study. BMI was measured and compared to standard tables. Information on possible risk factors was collected by questionnaire.

RESULTS

The prevalence of overweight and obesity was 6% and 1.3%, respectively. Significant associations were found between overweight and age, residency (urban-rural), birth rank, breast-feeding and certain dietary and lifestyle practices.

CONCLUSION

The prevalence of obesity and overweight is relatively high in children in central Iraq. Modern dietary habits are an important influence in the development of childhood obesity that should be watched carefully and controlled.

Associations between BMI, social strata and the estimated energy content of foods

OBJECTIVE

Many studies have shown that the prevalence of obesity is greater in lower social classes. The reasons for this effect however are unclear. Since there is also a link between education and social class, and an association between education and prevalence of obesity, one hypothesis is that lack of education about energy contents of foods may contribute to the effects of social class on obesity.

SUBJECTS

We tested the hypothesis that knowledge of food energy contents is associated with differences in body mass index (BMI) in a sample of 346 people of both genders, aged between 18 and 45 y, of variable body mass index and drawn from different social strata.

RESULTS

Estimates of food energy contents were on average well correlated with the actual energy contents, but individual estimates were very poor in all subpopulations of this sample. We found that subjects of different BMIs did not differentially estimate the energy contents of foods high in carbohydrate, but low in fat and protein (fruit and bread). However, foods that contained high fat contents, independent of the other macronutrients present, were generally perceived to have significantly lower energy contents by obese people than nonobese subjects (although this was not observed for all high-fat foods). Overall, this difference interacted with social class, such that the difference between the BMI groups was exaggerated in the lower social stratum but abolished in the higher social class. Binary logistic regressions revealed that the probability of being obese (BMI>30 kg/m2) in the lower social class group was significantly negatively associated with the estimated food energy content of most high-fat foods. Such an association was not found in the higher social class group. In the lower social class group, overall food knowledge appeared superior in the leaner subject group (BMI<30 kg/m2), but obese subjects were actually better at estimating the energy contents of snacks and alcoholic beverages. The leaner group significantly overestimated the energy contents of these items.

CONCLUSION

Differences between individuals in estimates of food energy contents may contribute to the development of obesity in lower social strata. Whether this is driven by a protective effect in lean subjects of overestimating the energy contents of certain foods (snacks and alcoholic beverages) or a susceptibility in the obese because they underestimate the energy contents of other foods is not certain. Knowing which of these alternatives is true is important and may help design public health education programmes directed at these people to help alleviate the obesity epidemic.

The effects of a family fitness program on the physical activity and nutrition behaviors of third-grade children

This study examined the efficacy of a school-based exercise and nutrition program with a parent component. Third-grade children (N = 238) from six elementary schools participated in the study, with three schools randomly assigned to a program group and the other three schools to a control group. The program group received a health-related fitness school-based program and a home program that required parents and children to complete activities and earn points for nutrition and exercise activities. The control group received their traditional physical education and nutrition education program. Univariate analysis of variance on pre- and posttest scores were completed on the following variables: height, weight, body mass index, skinfold, blood cholesterol, mile run, exercise and nutrition knowledge, calories, protein, carbohydrates, total fat, saturated fat, dietary cholesterol, fiber, sodium, percentage of calories from carbohydrates, and percentage of calories from fat. At pretest, the treatment and control groups did not significantly differ on the measures using schools as the unit of analysis. Girls scored significantly higher than boys on skinfold and pretest knowledge. At posttest, the treatment group scored significantly higher than the control group on exercise and nutrition knowledge and significantly lower than the control group on total fat intake, using schools as the unit of analysis. There was no improvement in physiological measures, including blood cholesterol. The study demonstrated that schools can adjust curriculum to meet some health needs of students and achieve modest changes in exercise and nutrition knowledge and diet. The family component of the program provided a practical approach to improving physical activity and nutrition behaviors for elementary school teachers who teach many participants in a crowded curriculum.

Dietary habits and children's family lives

PURPOSE

To investigate associations between 'less healthy eating' and 'unhealthy snacking' at age 11, and family life (family structure, meals and maternal employment status) together with potential socio-economic confounders and gender.

METHODS

Children participated in a school-based survey, questionnaires also being completed by parents. Analyses were based on those with complete data, weighted to account for bias in return of parental questionnaires (N = 2146). Data from a dietary inventory, questions on food choice and snacks were used to classify 'less healthy eating' and 'unhealthy snacking'.

RESULTS

Less healthy eating' (57%) and 'unhealthy snacking' (32%) were associated with greater deprivation, fewer maternal qualifications and being male. Compared with children of full-time homemakers, the likelihood of 'less healthy eating' was reduced among those whose mothers worked part-time (this effect remaining after socio-economic adjustment), full-time (effect removed after adjustment), or were unemployed, sick or disabled (effect emerging after adjustment). 'Unhealthy snacking' was not related to maternal employment, and neither measure was associated with family structure or daily meals.

CONCLUSIONS

There was no evidence that family structure or meals were associated with children's diets, although maternal employment had a positive association. Contrasting with the size of these effects, relationships between diet and socio-economic status were strong.

Stature and adiposity among children in contrasting neighborhoods in the city of Hamilton, Ontario, Canada

It is hypothesized in this study that body size and shape vary by local area within the North American urban environment. This study tests that hypothesis by comparing stature and adiposity among children (of age 6-10 years) attending elementary schools in three neighborhoods that contrast by socioeconomic status and recent immigrant status. While the whole sample of children (n = 266) has 27.4% of children that can be classified as overweight/obese (> or =85th percentile for body mass index), analysis by socioeconomic status (SES) reveals that there are approximately twice as many children in the overweight/obese category in the two low-SES schools compared to the high-SES school. Further analysis by individual school indicates that the school in the poorest neighborhood has a statistically significantly lower mean height-for-age Z score relative to the most affluent school. It is concluded that the influence of socioeconomic, demographic, and environmental factors on stature and adiposity can be investigated through studies such as this one that consider local area variation.

The relationship between parental nutritional status and overweight children/adolescents in Rio de Janeiro, Brazil

BACKGROUND

The association between overweight parents and overweight children/adolescents was investigated in Rio de Janeiro, Brazil between 1995 and 1996, controlling for the influence of socio-economic and demographic factors.

METHODS

Data were obtained from a two-stage, residence-based, random sample survey of children and adolescents aged 6-19 years and their parents. Body mass index (BMI) was used to classify nutritional status. Initially, a logistic regression model was built, using an indicator of parental weight (maternal BMI) as one of the independent variables and the child/adolescent's BMI as the dependent variable. Following that, the association between socio-economic and demographic variables and overweight children/adolescents was analysed in a univariate analysis. These variables were pre-selected for inclusion in the logistic model, provided that their levels of statistical significance were below P=0.25, and were added to the model individually according to the order of association strength in the univariate analysis. Finally, variables were retained in this model at a significance level of P=0.05.

RESULTS

This study found that 20.7% of girls and 26.9% of boys were overweight, with a larger prevalence among children aged less than 9 years. In addition to maternal BMI, the predictors of overweight children and adolescents were age, gender and the number of people in a house.

CONCLUSIONS

These results demonstrate the relationship between maternal nutritional status and overweight children and adolescents, suggesting that obesity-prevention programmes should be focused on the family.

Diet, Obesity and Education in Three Age Groups of Saskatchewan Women

Research on relationships between socioeconomic status and Canadians’ diet is limited. The current study investigated differences by education in dietary variables shown to be related to obesity; it included three age groups of Saskatchewan women who participated in the 1992 to 1993 Heart Health Intervention Evaluation baseline study. Multistage sampling was used to select randomly from the Saskatchewan Health Insurance Registration File. The overall response rate was 42.6%; a sample representative of the general Saskatchewan population was obtained. Three-day estimated food records and demographic information from 396 women aged 18 to 74 years were subdivided into three age categories: 18 to 34 years, 35 to 54 years, and 55 to 74 years. For the 18- to 34-year group, obesity was significantly more prevalent with lower education; trends were similar for the older age groups. Under-reporting of energy intake (indicated by an energy intake:basal metabolic rate ratio of <1.1) was related to obesity but not to education. The greatest differences in diet between educational groups were observed in the 18- to 34-year group; fewer differences existed in the 35- to 54-year group, and none in the 55- to 74-year group. Health promotion efforts need to be targeted appropriately, and based on differences in dietary intakes by socioeconomic group. Research should help promote an understanding of the reasons for differences in diet by socioeconomic status.

Obesity and associated modifiable environmental factors in Iranian adolescents: Isfahan Healthy Heart Program - Heart Health Promotion from Childhood

OBJECTIVE

To evaluate the prevalence of overweight and obesity among Iranian adolescents and their relationship with modifiable environmental factors.

METHODS

The subjects of the present study were 1000 girls and 1000 boys, aged between 11 and 18 years selected by multistage random sampling, their parents (n = 2000) and their school staff (n = 500 subjects) in urban and rural areas of two provinces in Iran. Data concerning body mass index (BMI), nutrition and the physical activity of the subjects were analyzed by SPSSV10/Win software.

RESULTS

The prevalence of 85th percentile </= body mass index (BMI) < 95th percentile and BMI > 95th percentile in girls was significantly higher than boys (10.7 +/- 1.1 and 2.9 +/- 0.1%vs 7.4 +/- 0.9 and 1.9 +/- 0.1%, respectively; P < 0.05). The mean BMI value was significantly different between urban and rural areas (25.4 +/- 5.2 vs 23.2 +/- 7.1 kg/m2, respectively; P < 0.05). A BMI> 85th percentile was more prevalent in families with an average income than in high-income families (9.3 +/- 1.7 vs 7.2 +/- 1.4%, respectively; P < 0.05) and in those with lower-educated mothers (9.2 +/- 2.1 vs 11.5 +/- 2.4 years of mothers education, respectively). The mean total energy intake was not different between overweight or obese and normal-weight subjects (1825 +/- 90 vs 1815 +/- 85 kCal, respectively; P > 0.05), but the percentage of energy derived from carbo-hydrates was significantly higher in the former group compared with the latter (69.4 vs 63.2%, respectively; P < 0.05). Regular extracurricular sports activities were significantly lower and the time spent watching tele-vision was significantly higher in overweight or obese than non-obese subjects (time spent watching telelvision: 300 +/- 20 vs 240 +/- 30 min/day, P < 0.05). A significant linear association was shown between the frequency of consumption of rice, bread, pasta, fast foods and fat/salty snacks and BMI (beta = 0.05-0.06; P < 0.05). A significant correlation was shown between BMI percentiles and serum triglyceride, high-density lipoprotein-cholesterol and systolic blood pressure (Pearson's r = 0.38, -0.32 and 0.47, respectively).

CONCLUSIONS

Enhanced efforts to prevent and control overweight from childhood is a critical national priority, even in developing countries. To be successful, social, cultural and economic influences should be considered.

Prevalência de obesidade em escolares de Salvador, Bahia

A obesidade em crianças é preocupante devido ao risco aumentado de sua persistência na idade adulta, e pelos riscos de doenças a ela relacionadas. Neste trabalho descrevemos a prevalência de obesidade em uma amostra representativa de alunos de escolas públicas e particulares de Salvador, Bahia. Foram estudados 387 alunos, com idade entre 5 e 10 anos, sendo 55% do sexo masculino, e 66% alunos de escolas públicas, selecionados através de amostragem por conglomerados. A obesidade foi definida a partir do índice de massa corporal (IMC) igual ou maior que o percentil 95 para idade e sexo de acordo com a recomendação de Himes (1994), utilizando as tabelas de Anjos (1998). Para análise estatística, aplicou-se o teste de igualdade de proporções. Nas escolas particulares, observou-se uma maior prevalência de obesidade (30%) em relação às escolas públicas (8%) (p< 0,001). As freqüências de obesidade em relação ao sexo e grupo racial entre escolas públicas e particulares foram semelhantes. Observou-se maior percentual de obesos na faixa de idade entre 7 e 9 anos nas escolas particulares e entre 9 e 10 anos nas escolas públicas. Para a população estudada, a análise das proporções aponta na direção de uma associação direta entre obesidade e nível sócio-econômico.