Shifting curves? Trends in thinness and obesity among Australian youth, 1985 to 2010

Area-level socioeconomic disparity trends in nutritional status among 5-6-year-old children in Israel

OBJECTIVE

This study aimed to assess area-level socioeconomic position (SEP) disparities in nutritional status, to determine whether disparities differed by sex and to assess whether nutritional status and disparities changed over time.

DESIGN

We used repeated cross-sectional data from a national programme that evaluates the quality of healthcare in Israel to assess children's nutritional status.

SETTING

The study included all Israeli residents aged 7 years during 2014-2018 (n=699 255).

METHODS

SEP was measured based on the Central Bureau of Statistics' statistical areas, and grouped into categories, ranging from 1 (lowest) to 10 (highest). We used multivariable multinomial regression to assess the association between SEP and nutritional status and between year and nutritional status. We included interactions between year and SEP to assess whether disparities changed over time.

RESULTS

Children in SEP 1, comprised entirely of children from the Bedouin population from Southern Israel, had drastically higher odds of thinness compared with those in the highest SEP (Girls: OR 5.02, 99% CI 2.23 to 11.30; Boys: OR 2.03, 99% CI 1.19 to 3.48). Odds of obesity were highest in lower-middle SEPs (OR_{SEP 5 vs 10} 1.84, 99% CI 1.34 to 2.54). Prevalence of overweight and obesity decreased between 2014 and 2018, normal weight increased and thinness did not change. SEP disparities in thinness decreased over time in boys but showed a reverse trend for girls. No substantial improvement was seen in SEP disparities for other weight categories.

CONCLUSIONS

Our study demonstrates the need to consider initiatives to combat the considerable SEP disparities in both thinness and obesity.

Trends in prevalence of thinness, overweight and obesity among Swedish children and adolescents between 2004 and 2015

AIM

This study explored weight trends among children aged 4, 7, 11, 14 and 17 years in Jönköping County Sweden, from 2004 to 2015.

METHODS

The study had a repeated cross-sectional design, and body mass index (BMI) was calculated based on height and weight measurements collected from child health and school health records. The prevalence of thinness, overweight and obesity was estimated with international cut-offs, with linear trends calculated separately for boys and girls.

RESULTS

There were 190 965 measurements of BMI and these covered 82-97% of the younger children and 55-69% of the older children during the study period. The prevalence of thinness varied between 0.2% and 2.2% across time and age groups and did not change over the study period. There was a small decrease in overweight among both girls and boys aged four years. There were increasing trends in overweight and obesity in both girls and boys aged 11 and 14 years of age and a sharp increase among 17-year-old boys, with 7.3% obese in 2014/2015 and 3.6% in 2004/2005.

CONCLUSION

The prevalence of obesity decreased from 2004 to 2015 or was stable in younger Swedish children, but increased among older children, with a large increase in adolescent boys.

School-based systems change for obesity prevention in adolescents: outcomes of the Australian Capital Territory 'It's Your Move!'

OBJECTIVE

The Australian Capital Territory 'It's Your Move!' (ACT-IYM) was a three-year (2012-2014) systems intervention to prevent obesity among adolescents.

METHODS

The ACT-IYM project involved three intervention schools and three comparison schools and targeted secondary students aged 12-16 years. The intervention consisted of multiple initiatives at individual, community, and school policy level to support healthier nutrition and physical activity. Intervention school-specific objectives related to increasing active transport, increasing time spent physically active at school, and supporting mental wellbeing. Data were collected in 2012 and 2014 from 656 students. Anthropometric data were objectively measured and behavioural data self-reported.

RESULTS

Proportions of overweight or obesity were similar over time within the intervention (24.5% baseline and 22.8% follow-up) and comparison groups (31.8% baseline and 30.6% follow-up). Within schools, two of three the intervention schools showed a significant decrease in the prevalence of overweight and obesity (p<0.05).

CONCLUSIONS

There was some evidence of effectiveness of the systems approach to preventing obesity among adolescents. Implications for public health: The incorporation of systems thinking has been touted as the next stage in obesity prevention and public health more broadly. These findings demonstrate that the use of systems methods can be effective on a small scale.

Secular trends in the prevalence of childhood overweight and obesity across Australian states: A meta-analysis

OBJECTIVE

To describe secular trends in the prevalence of overweight and obesity in Australian children in each state and territory.

DESIGN

Systematic search and numerical meta-analysis.

METHODS

A systematic search was conducted to identify all sources that objectively measured the height and weight of Australian children (aged 2-18 years) and had a sample size of at least 300. Raw and summary data were requested from authors and divided into age×sex×state×yearly slices to derive estimates of the prevalence of overweight and obesity. Following a double arcsine transformation to facilitate meta-analysis, all estimates were standardised for age, stratified by sex and analysed using sample-weighted non-linear regressions.

RESULTS

The systematic search identified 73 eligible sources (47 raw and 26 summary datasets), with 72.8% of data sourced from Victoria and South Australia. Prevalence trends varied from state to state, with three states or territories showing a marked plateau, two showing a decline in the more recent years and three showing continued linear increases. Tasmania and Northern Territory generally had the highest prevalence (30.2% and 24.3% overweight and obesity respectively), and the Australian Capital Territory had the lowest (12.4% overweight and obesity).

CONCLUSIONS

Prevalence, as well as prevalence trends, varied amongst Australian states and territories. At a national level, the prevalence trend has nearly plateaued for the past 15 years. However, upward prevalence trends appear to be persisting in Western Australia, South Australia and Tasmania. Findings highlight the need for ongoing efforts to address the issue of childhood obesity.

Do thin, overweight and obese children have poorer development than their healthy-weight peers at the start of school? Findings from a South Australian data linkage study

Little is known about the holistic development of children who are not healthy-weight when they start school, despite one fifth of preschool-aged children in high income countries being overweight or obese. Further to this, there is a paucity of research examining low body mass index (BMI) in contemporary high-income populations, although evidence from the developing world demonstrates a range of negative consequences in childhood and beyond. We investigated the development of 4-6 year old children who were thin, healthy-weight, overweight, or obese (as defined by BMI z-scores) across the five domains of the Australian Early Development Census (AEDC): Physical Health and Wellbeing, Social Competence, Emotional Maturity, Language and Cognitive Skills, and Communication Skills and General Knowledge. We used a linked dataset of South Australian routinely collected data, which included the AEDC, school enrollment data, and perinatal records (n = 7533). We found that the risk of developmental vulnerability among children who were thin did not differ from healthy-weight children, after adjusting for a range of perinatal and socio-economic characteristics. On the whole, overweight children also had similar outcomes as their healthy-weight peers, though they may have better Language and Cognitive skills (adjusted Risk Ratio [aRR] = 0.73 [95% CI 0.50-1.05]). Obese children were more likely to be vulnerable on the Physical Health and Wellbeing (2.20 [1.69, 2.87]) and Social Competence (1.31 [0.94, 1.83]) domains, and to be vulnerable on one or more domains (1.45 [1.18, 1.78]). We conclude that children who are obese in the first year of school may already be exhibiting some developmental vulnerabilities (relative to their healthy-weight peers), lending further support for strategies to promote healthy development of preschoolers.

Prevalence of grade 1, 2 and 3 thinness is associated with lower socio-economic status in children in Shanghai, China

Objective

We aimed to investigate the prevalence of grade 1, 2 and 3 thinness among Chinese children and to explore their associations with socio-economic status (SES).

Design

A population, school-based cross-sectional study using multistage, stratified cluster random sampling. Grade 1, 2 and 3 thinness, overweight, obesity and severe obesity were defined by the International Obesity Task Force BMI cut-offs.

Setting

Seven districts of Shanghai, China.

Subjects

Chinese children aged 3–12 years (n 84 075).

Results

In boys and girls, respectively, the prevalence of grade 1 thinness was 8·89 % and 11·78 %, of grade 2 thinness was 2·80 % and 3·74 %, and of grade 3 thinness was 2·23 % and 2·93 %. Compared with urban children, suburban children had higher prevalence of thinness. Children whose parent had low education had higher prevalence of grade 1, 2 and 3 thinness than those whose parent had high education. The prevalence of grade 2 and 3 thinness, obesity and severe obesity in low-SES children was higher than that in high-SES children, and the prevalence of grade 1 thinness was lower than that in high-SES children. Particular patterns of prevalence of grade 1, 2 and 3 thinness appeared in low-, middle- and high-SES children.

Conclusions

The study describes associations of SES with grade 1, 2 and 3 thinness, overweight, obesity and severe obesity in Shanghai children. The patterns of thinness and obesity in Shanghai provide further insights into BMI patterns in mega-cities in developing countries.

Effectiveness of a behavioral incentive scheme linked to goal achievement: study protocol for a randomized controlled trial

BACKGROUND

Childhood obesity is a concern in Australia and across the world. Community-based weight management programs are an important response to address childhood obesity. However, the scientific literature suggests that their effectiveness could potentially be enhanced by providing a structured incentive scheme. This proposal aims to determine the effectiveness of enhanced goal setting linked to a structured incentive scheme designed to improve the sustained health and wellbeing of overweight/obese children within the context of an existing community-based program.

METHODS/DESIGN

This study is a cluster randomized controlled trial delivered within the context of the existing NSW "Go4Fun" program with a 10-week and 6- and 12-month follow-up (n = 40 sites, 570 participants) that compares the effectiveness of small changes to the program in which children were asked to set goals (supported by text messages) and were given rewards for achieving them (intervention). This will be compared to the standard/existing program (control), which did not have the same structured incentive program. Data will be collected for all participants at baseline, end of program, and at 6 and 12 months. The primary outcome is a mean change in body mass index (BMI) z score at the 12-month follow-up. Secondary outcomes include anthropometric measures (body weight, height, and waist circumference) and behavioral measures collected via validated questionnaires. A process evaluation (comprising surveys and focus groups) to determine acceptability and sustainability and to inform downstream translation will also be conducted.

DISCUSSION

This study will inform policy and program delivery as well as the broader evidence base regarding goal achievement and incentive schemes directed at children's health-related behaviors and will provide evidence that is likely to be transferrable across a range of health conditions.

TRIAL REGISTRATION

ACTRN12615000558527 registered on 29 May 2015.

Disadvantaged children at greater relative risk of thinness (as well as obesity): a secondary data analysis of the England National Child Measurement Programme and the UK Millennium Cohort Study

Introduction

Young children living in more disadvantaged socio-economic circumstances (SECs) are at an increased risk of overweight and obesity. However, there is scant research examining the prevalence and social distribution of thinness in early childhood, despite potential negative consequences for health and development across the life-course.

Methods

We examined the social gradient in thinness (and overweight and obesity for comparison) for 2,620,422 four-to-five year olds attending state maintained primary schools from 2007/8 to 2011/12, in the England National Child Measurement Programme (NCMP), and 16,715 children from the UK Millennium Cohort Study (MCS), born in 2000–2002, and measured at ages of three, five and seven. Children were classified as being thin, healthy weight (and, for completeness, overweight or obese) using international age and sex adjusted cut-offs for body mass index (BMI). Prevalences (and 95 % confidence intervals (CIs)) were estimated, overall, and according to SECs: area deprivation (NCMP, MCS); household income, and maternal social class and education (MCS only). Relative Risk Ratios (RRRs) and CIs for thinness, overweight and obesity were estimated in multinomial models by SECs (baseline healthy weight). In the MCS, standard errors were estimated using clustered sandwich estimators to account for repeated measures, and, for thinness, RRRs by SECs were also estimated adjusting for a range of early life characteristics.

Results

In 2007/8 to 2011/12, 5.20 % of four-to-five year old girls (n = 66,584) and 5.88 % of boys (78,934) in the NCMP were thin. In the MCS, the prevalence of thinness was 4.59 % (693) at three, 4.21 % (702) at five, and 5.84 % (804) at seven years. In both studies, and for all measures of SECs, children from the most disadvantaged groups were more likely to be thin than those from the most advantaged groups. For example, MCS children whose mothers had no educational qualifications were fifty percent more likely to be thin (RRR 1.5 (CI: 1.24, 1.8)) than those whose mothers had a degree. These patterns were attenuated but remained after adjusting for early life characteristics.

Conclusions

Children from more disadvantaged backgrounds are at elevated relative risk of thinness as well as obesity. Researchers and policymakers should consider environmental influences on thinness in addition to overweight and obesity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12939-015-0187-6) contains supplementary material, which is available to authorized users.

Childhood obesity and its physical and psychological co-morbidities: a systematic review of Australian children and adolescents

Australia is predicted to have the highest overweight/obesity rate in the world by 2022 outranking the USA and UK. The purpose of this systematic review was to evaluate the associations between childhood obesity and physical and psychological health co-morbidities. Therefore, a systematic literature search was conducted from six databases (2004-2014). Studies were included if they investigated obesity-related co-morbidities with participants residing in Australia aged 0-18 years. Forty-seven studies fulfilled selection criteria. Evidence suggests that overweight/obese Australian children and adolescents, compared to normal-weight peers, had more cardio-metabolic risk factors and higher risk factors of non-alcohol fatty liver disease and were experiencing more negative psychological outcomes (depression, low self-esteem and lower scores of health-related quality of life). Many other health consequences have either not been investigated in Australia, or as frequently as in other countries.

CONCLUSIONS

Given Australia's current overweight/obesity prevalence and trajectory, Australia-based studies are needed to identify the suspected co-morbidities, understand the range of individual, social and environmental mechanisms driving obesity, and help identify policies, interventions and strategies that will change the future trajectory and 'disease burden' both in Australia and internationally.

WHAT IS KNOWN

• Trend analyses have shown that obesity prevalence in Australia is increasing and will outrank UK and the USA by 2022. • Every third Australian child/adolescent between 5 and 19 years old is predicted to be classified as overweight or obese by 2025. • Childhood obesity is associated with multiple immediate physical and psychological health co-morbidities as well as co-morbidities in adulthood. These have often been identified and examined individually. What is New: • This paper presents a holistic picture of childhood obesity and the associated multiple co-morbidities in Australia. • The extensive health-related outcomes from childhood obesity and those requiring further research are identified. • The findings of this paper will influence the development of local/regional, state and national strategies to change Australia's future trajectory.

IQ and obesity in adolescence: a population-based, cross-sectional study

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Low IQ is associated with high BMI in childhood. There are inconsistent findings on the association between low SES and high BMI. Youth with low IQ have been reported to have poorer health behaviors, such as poor nutrition and less physical activity.

WHAT THIS STUDY ADDS

Low IQ is significantly associated with obesity for both male and female adolescents, though more strongly for female adolescents. Physical activity has a mediating effect on the association between low IQ and obesity among both male and female adolescents, though more strongly for male adolescents. The association between low IQ and obesity is strongest among adolescents from high SES backgrounds.

BACKGROUND

Previous studies have shown an association between low intelligence quotient (IQ), high body mass index and low socioeconomic status (SES).

OBJECTIVES

This study examined the cross-sectional association between IQ and obesity, exploring the roles of gender, SES and physical activity in this association.

METHODS

Subjects were 235,663 male and 169,259 female adolescents assessed by the Israeli military draft board.

RESULTS

Low IQ was significantly associated with increased odds of obesity among male (odds ratio [OR] = 1.44, 95% confidence interval [CI] = 1.36-1.52) and female adolescents (OR = 1.61, 95% CI = 1.51-1.73); this association was significantly stronger among female adolescents. Sobel tests indicated that physical activity had a significant mediating effect on this association for male and female adolescents, although more strongly for male adolescents. Dividing the sample according to SES, the association between low IQ and obesity was strongest in the high SES group (male adolescents: OR = 1.26, 95% CI = 1.10-1.43, female adolescents: OR = 1.61, 95% CI = 1.38-1.89), even when controlling for physical activity.

CONCLUSIONS

The findings suggest that low IQ is associated with increased odds of obesity, particularly in female adolescents and in adolescents with high SES. Physical activity has a mediating effect on this association, although more strongly for male than for female adolescents. Public health measures on decreasing obesity might focus on these groups.

Thinness in the era of obesity: trends in children and adolescents in The Netherlands since 1980

BACKGROUND

Although children both at the upper and lower tail of the body mass index (BMI) distribution are at greater health risk, relatively little is known about the development of thinness prevalence rates in developed countries over time. We studied trends in childhood thinness and assessed changes in the BMI distribution since the onset of the obesity epidemic.

METHODS

Growth data from 54 814 children aged 2-18 years of Dutch, Turkish and Moroccan origin living in The Netherlands were used. Anthropometric measurements were performed during nationwide cross-sectional growth studies in 1980 (only Dutch), 1997 and 2009. Prevalence rates of thinness grades I, II and III were calculated according to international cut-offs. BMI distributions for 1980, 1997 and 2009 were compared.

RESULTS

Since 1980, thinness (all grades combined) reduced significantly from 14.0% to 9.8% in children of Dutch origin, but the proportion of extremely thin children (grade III) remained constant. Thinness in children of Moroccan origin decreased significantly from 8.8% to 6.2% between 1997 and 2009. No significant difference was observed in children of Turkish origin (5.4% in 1997 vs. 5.7% in 2009). Thinness occurred most often in children aged 2-5 years. There were no differences between boys and girls. The BMI distribution widened since 1980, mainly due to an upward shift of the upper centiles.

CONCLUSION

Since the onset of the obesity epidemic, prevalence rates of thinness decreased. However, we found a small but persistent group of extremely thin children. More research is needed to gain insight into their health status.

Socioeconomic patterns of overweight, obesity but not thinness persist from childhood to adolescence in a 6-year longitudinal cohort of Australian schoolchildren from 2007 to 2012

Background

The prevalence of childhood overweight and obesity increased during the 1980s to the late 1990s. The prevalence of obesity is higher in socially and economically disadvantaged communities in most Westernised countries. The purpose of this study was to examine how the socioeconomic gradient in weight status, namely thinness, overweight and obesity, changes over time in a longitudinal cohort of Australian schoolchildren, from 2007–2012.

Methods

939 Australian children in school grades 2–6 from 10 primary schools initially participated in the study in 2007. Height and weight were directly measured by research assistants each year. Obesity/overweight and thinness were defined by using the International Obesity Task Force BMI cut-offs. Chi-square analyses were used to test associations between categorical variables and linear mixed models were used to estimate whether the differences in SES groups were statistically significant over time.

Results

Results found both males and females in the low SES group were more likely to be obese (6-7%) than middle (4-5%) and high (2-3%) SES groups and this pattern tended to be similar over the 6 year study period. There appeared to be no particular SES pattern for thinness with all SES groups having 4-5% of participants who were thin. The gender and SES patterns were also similar over 6 years for BMI with low and middle SES participants having significantly greater BMI than their high SES peers.

Conclusions

Patterns of obesity and overweight in children from socially and economically disadvantaged communities in regional NSW are identifiable from a young age and the socioeconomic pattern persists into adolescence. Obesity prevention and intervention programs should be designed, implemented and evaluated with the social determinants of health in mind and in collaboration with community members. Community programs should continue to be based on positive rather than negative messages in order to avoid unintended stigma and other potentially harmful outcomes.

Process evaluation of an up-scaled community based child obesity treatment program: NSW Go4Fun®

Background

Community-based obesity treatment programs for children that have a large program reach are a priority. To date, most programs have been small efficacy trials whose findings have yet to be up-scaled and translated into real-world settings. This paper reports on the process evaluation of a government-funded, translated obesity treatment program for children in Australia. It describes the characteristics and reach of children participating in the New South Wales (NSW) Ministry of Health Go4Fun® program.

Methods

Delivered across the state of NSW (Australia) by Local Health Districts (LHDs), Go4Fun® is a community-based, multidisciplinary family obesity treatment program adapted from the United Kingdom Mind Exercise Nutrition Do it (MEND) program that targets weight-related behaviours. Children aged 7-13 years with a BMI ≥85^th percentile and no co-morbidities were eligible at no cost. Parents/carers self-refer via a toll-free phone number, text messages, online registration or via secondary referrals. LHDs deliver a 16 to 20-session program based on length of school term, holidays and recruitment challenges. Both parent/carer and child attend bi-weekly after school sessions. Parent-reported socio-demographic and measured child weight characteristics are presented using descriptive statistics. Differences between completers (attended at least 75% of sessions) and non-completers were assessed using chi-square tests, independent sample t-tests and adjusted odds ratios. Analyses were adjusted for clustering of programs.

Results

Between 2009 and 2012, a total of 2,499 children (54.8% girls; mean age [SD]: 10.2 [1.7 years]) participated in the Go4Fun® program. Children were mainly from low-middle socioeconomic status (76.5%), resided in major cities (63.3%), and 5.7% were Aboriginal. At baseline, 96.5% of children were overweight or obese. Mean BMI-z-score was 2.07 (0.41) and 94.5% had a waist-to-height ratio ≥0.5. More than half (57.9%) completed at least 75% of sessions. Amongst completers (N = 1,446), girls (56.8%; p = 0.02), non-Aboriginal children (95.9%; p < 0.01) and children residing in less socially disadvantaged areas (25.9%; p = 0.02) were significantly more likely to complete the program.

Conclusions

The Go4Fun® program successfully reached the targeted population of overweight/obese children at socioeconomic disadvantage and is a rare example of an up-scaled translational program.

Variation in outcomes of the Melbourne Infant, Feeding, Activity and Nutrition Trial (InFANT) Program according to maternal education and age

OBJECTIVE

To assess the effectiveness of the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program according to maternal education and age.

METHODS

A cluster-randomised controlled trial involving 542 mother/infant pairs from 62 existing first-time parent groups was conducted in 2008 in Melbourne, Australia. The intervention involved 6 × 2-hour dietitian-delivered sessions, DVD and written resources from infant age 4-15 months. Outcomes included infant diet (3 × 24 h diet recalls), physical activity (accelerometry), television viewing and body mass index. We tested for moderation by maternal education (with/without a University degree) and age (< 32 and ≥ 32 years). The trial was registered with the ISRCTN Register (identifier 81847050).

RESULTS

Interaction effects with the treatment arm were observed for maternal education and age. The intervention effects on vegetable (positive effect) and sweet snack consumption (negative effect) were greater in children with higher educated mothers while intervention effects on water consumption (positive effect) were greater in infants with lower educated mothers. The intervention was also more effective in increasing both vegetable and water consumption in infants with mothers aged < 32 years.

CONCLUSIONS

Child obesity prevention interventions may be differentially effective according to maternal education and age. Evidence of differential effects is important for informing more sensitively targeted/tailored approaches.

Socio-cultural differences in Australian primary school children's weight and weight-related behaviours

AIM

To examine whether there are socio-cultural differences in overweight/obesity and weight-related behaviours of Australian primary school children.

METHODS

Secondary data analysis of the 2010 NSW Schools Physical Activity and Nutrition Survey (n = 4898). Height and weight were measured. Parents of Year K, 2, 4 children and Year 6 students completed a questionnaire on demographics and weight-related behaviours. Cardio-respiratory fitness was assessed by the 20-meter shuttle run test and categorised as adequately fit or unfit. Children were categorised according to the main cultural/ethnic backgrounds (Middle-Eastern, Asian and English-speaking backgrounds) and socio-economic status (SES) tertile.

RESULTS

Within ethnic groups, SES was associated with weight-related behaviours, but not consistently, and not with body mass index status. Within ethnic groups, the odds were higher among low SES, compared with high SES to be inactive, unfit and have poorer dietary habits. Weight-related behaviours among each ethnic group also differed by gender. Compared with low SES children from English-speaking backgrounds, ethnic boys were two times as likely to be overweight/obese, and the odds were significantly higher among ethnic children to be inactive, unfit and have poor dietary patterns.

CONCLUSION

The results indicate the need for obesity prevention initiatives to specifically target and reach children from low SES and Asian and Middle-Eastern backgrounds, and the importance of ensuring that such initiatives are culturally appropriate and address relevant issues.