Drivers of Overweight/Obesity in 4–11 Year Old Children of Australians and Immigrants; Evidence from Growing Up in Australia

Differences in weight status among Australian children and adolescents from priority populations: a longitudinal study

BACKGROUND AND SIGNIFICANCE

Australia has a high level of cultural and linguistic diversity, including Aboriginal and Torres Strait Islander peoples. Children from specific cultural and ethnic groups may be at greater risk of overweight and obesity and may bear the additional risk of socioeconomic disadvantage. Our aim was to identify differences in body-mass index z-score (zBMI) by: (1) Cultural and ethnic groups and; (2) Socioeconomic position (SEP), during childhood and adolescence.

SUBJECTS/METHODS

We used data from the Longitudinal Study of Australian children (n = 9417) aged 2-19 years with 50870 longitudinal measurements of zBMI. Children were classified into 9 cultural and ethnic groups, based on parent and child's country of birth and language spoken at home. These were: (1) English-speaking countries; (2) Middle East & North Africa; (3) East & South-East Asia; (4) South & Central Asia; (5) Europe; (6) Sub-Saharan Africa; (7) Americas; (8) Oceania. A further group (9) was defined as Aboriginal and Torres Strait Islander from self-reported demographic information. Longitudinal cohort analyses in which exposures were cultural and ethnic group and family socioeconomic position, and the outcome was zBMI estimated using multilevel mixed linear regression models. We stratified our analyses over three periods of child development: early childhood (2-5 years); middle childhood (6-11 years); and adolescence (12-19 years).

RESULTS

Across all three periods of child development, children from the Middle East and North Africa, the Americas and Oceania were associated with higher zBMI and children from the two Asian groups were associated with lower zBMI, when compared to the referent group (English). zBMI was socioeconomically patterned, with increasingly higher zBMI associated with more socioeconomic disadvantage.

CONCLUSIONS

Our findings identified key population groups at higher risk of overweight and obesity in childhood and adolescence. Prevention efforts should prioritize these groups to avoid exacerbating inequalities in healthy weight in childhood.

Empirical evidence of predictive adaptive response in humans: systematic review and meta-analysis of migrant populations

Meta-analysis is used to test a variant of a Developmental Origins of Adult Health and Disease (DOHaD)'s conjecture known as predictive adaptive response (PAR). According to it, individuals who are exposed to mismatches between adverse or constrained in utero conditions, on the one hand, and postnatal obesogenic environments, on the other, are at higher risk of developing adult chronic conditions, including obesity, type 2 diabetes (T2D), hypertension and cardiovascular disease. We argue that migrant populations from low and middle to high-income countries offer a unique opportunity to test the conjecture. A database was constructed from an exhaustive literature search of peer-reviewed papers published prior to May 2021 contained in PUBMED and SCOPUS using keywords related to migrants, DOHaD, and associated health outcomes. Random effects meta-regression models were estimated to assess the magnitude of effects associated with migrant groups on the prevalence rate of T2D and hypertension in adults and overweight/obesity in adults and children. Overall, we used 38 distinct studies and 78 estimates of diabetes, 59 estimates of hypertension, 102 estimates of overweight/obesity in adults, and 23 estimates of overweight/obesity in children. Our results show that adult migrants experience higher prevalence of T2D than populations at destination (PR 1.48; 95% CI 1.35-1.65) and origin (PR 1.80; 95% CI 1.40-2.34). Similarly, there is a significant excess of obesity prevalence in children migrants (PR 1.22; 95% CI 1.04-1.43) but not among adult migrants (PR 0.89; 95% CI 0.80-1.01). Although the total effect of migrant status on prevalence of hypertension is centered on zero, some migrant groups show increased risks. Finally, the size of estimated effects varies significantly by migrant groups according to place of destination. Despite limitations inherent to all meta-analyses and admitting that some of our findings may be accounted for alternative explanations, the present study shows empirical evidence consistent with selected PAR-like conjectures.

Psychosocial and environmental risk factors of obesity and hypertension in children and adolescents-a literature overview

Childhood obesity has become a worldwide epidemic in the 21st century. Its treatment is challenging and often ineffective, among others due to complex, often not obvious causes. Awareness of the existence and meaning of psychosocial and environmental risk factors seems to be an essential element in the prevention and treatment of obesity and its complications, especially arterial hypertension. In this review, we will discuss the role of that risk factors linking obesity and increased cardiovascular disorders including the role of nutritional factors (including the role of unhealthy diet, inadequate hydration), unhealthy behaviors (e.g. smoking, alcohol and drugs, sedentary behavior, low physical activity, disrupted circadian rhythms, sleep disorders, screen exposure), unfavorable social factors (such as dysfunctional family, bullying, chronic stress, mood disorders, depression, urbanization, noise, and environmental pollution), and finally differences in cardiovascular risk in girls and boys.

Obesity diagnoses in children and adolescents in Norway by immigrant background

AIM

Relatively few obese children and adolescents receive specialist treatment. Our aim was to assess associations between risk of receiving an obesity diagnosis in secondary/tertiary health services by socio-economic position and immigrant background in order ultimately to improve equity in health services.

METHODS

The study population comprised Norwegian-born children aged 2-18 years between 2008 and 2018 (N=1,414,623), identified via the Medical Birth Registry. Cox regressions were used to calculate hazard ratios (HR) of an obesity diagnosis from secondary/tertiary health services (Norwegian Patient Registry) by parental education and household income and by immigrant background.

RESULTS

Higher parental education and household income were associated with a lower hazard of obesity diagnosis regardless of Norwegian versus immigrant background. Compared to having a Norwegian background, having a Latin American (HR=4.12; 95% confidence interval (CI) 3.18-5.34), African (HR=1.54; 95% CI 1.34-1.76) and Asian (HR=1.60; 95% CI 1.48-1.74) background was associated with higher hazard of obesity diagnosis. Adjusted for parental education and household income, corresponding HRs were 3.28 (95% CI 2.95-3.65) for Latin America, 0.95 (95% CI 0.90-1.01) for Africa and 1.08 (95% CI 1.04-1.11) for Asia. Within Asia, those with a background from Pakistan, Turkey, Iraq and Iran had higher hazards than those with a Norwegian background, while those with a background from Vietnam had lower hazards, even after adjusting for parental education and household income.

CONCLUSIONS

To ensure more equitable treatment, more knowledge is warranted about health-service access and referral patterns, and underlying population prevalence rates, for obese children and adolescents with different immigrant backgrounds.

Trends and determinants of organised sports participation in immigrant and Australian children: A nine-year follow-up

OBJECTIVES

This study aimed to examine trends and determinants of organised sports participation among children of immigrant parents from low-and-middle-income countries, high-income countries, and Australian children.

DESIGN

Longitudinal (nine-year follow-up).

METHODS

Data were from the birth-cohort of Australian Children aged 6-15 years with follow-up between 2010 and 2018. Organised sports participation was measured using two items about regular participation in team and individual sports. Multilevel logit modelling was used to assess the determinants of organised sports participation across groups.

RESULTS

Both team sports participation and individual sports participation increased between 6 and 11 years and declined between 11 and 15 years across the three groups. Children of immigrant parents from low-and-middle-income countries (OR 0.65; 95 % CI 0.57-0.74) and high-income countries (OR 0.82; 95 % CI 0.76-0.89) had lower odds of team sports participation than Australian children. Children of immigrant parents from low-and-middle-income countries had lower odds of team sports participation (OR 0.79; 95 % CI 0.69-0.90) than children of immigrant parents from high-income countries. Female children, high screen time, high psychological difficulties, increased number of siblings and low socio-economic position were identified as determinants of lower team and individual sports participation.

CONCLUSIONS

The present study identified evidence of disparities in organised sports participation among children of immigrant parents and Australian children. Multilevel and multicomponent interventions to promote children's organised sports participation should be prioritised, with a focus on children of the female sex, older children, children with lower socioeconomic status, and children with higher screen time and higher psychological difficulties.

Childhood obesity risk increases with increased screen time: a systematic review and dose-response meta-analysis

BACKGROUND

The role of screen time in promoting obesity among children has been reported in previous studies. However, the effects of different screen types and the dose-response association between screen time and obesity among children is not summarized yet. In the current meta-analysis we systematically summarized the association between obesity and screen time of different screen types in a dose-response analysis.

METHODS

A systematic search from Scopus, PubMed and Embase electronic databases was performed. Studies that evaluated the association between screen time and obesity up to September 2021 were retrieved. We included 45 individual studies that were drawn from nine qualified studies into meta-analysis.

RESULTS

The results of the two-class meta-analysis showed that those at the highest category of screen time were 1.2 times more likely to develop obesity [odds ratio (OR) = 1.21; confidence interval (CI) = 1.113, 1.317; I2 = 60.4%; P < 0.001). The results of subgrouping identified that setting, obesity status and age group were possible heterogeneity sources. No evidence of non-linear association between increased screen time and obesity risk among children was observed (P-nonlinearity = 0.310).

CONCLUSION

In the current systematic review and meta-analysis we revealed a positive association between screen time and obesity among children without any evidence of non-linear association. Due to the cross-sectional design of included studies, we suggest further studies with longitudinal or interventional design to better elucidate the observed associations.

Food behaviours and eating habits among Sub-Saharan African migrant mothers of school-aged children in South Australia

Overweight, obesity and chronic conditions like diabetes, stroke and heart disease represent a significant burden to public health. Traditional foods and healthy dietary habits can reduce the risk of these conditions. Therefore, this study aimed to explore traditional food patterns and eating habits among Sub-Saharan African migrant mothers of school-aged children in South Australia. The study was a qualitative inquiry that used face-to-face interviews with 15 mothers of school-aged children in South Australia. Snowballing was used to sample participants, and data were audio-recorded, transcribed verbatim, coded, and analysed thematically. Four broad themes described participants' food behaviours and eating habits, including maintaining traditional food patterns, changes in traditional food patterns and eating habits, concerns with food environments in Australia, and challenges with traditional food availability and access in Australia. This study found that although mothers were committed to maintaining their traditional foods, they found it increasingly difficult to continue such habits. Participants reported challenges as their children are increasingly demanding westernised foods. While some parents pushed back against such demands from their children, others felt helpless and relented. Some views showed that food environments, food systems, access, and scarcity of traditional foods in Australia influenced the participants' food patterns and eating habits. Appropriately tailored healthy eating health promotion actions targeting school-aged children and mothers in this population need to consider their food contexts. Promoting the use of traditional foods, their preparation practices, and processing might be helpful in this community when developing healthy eating programs.

Unhealthy Food and Beverage Consumption in Children and Risk of Overweight and Obesity: A Systematic Review and Meta-Analysis

This WHO-commissioned review contributed to the update of complementary feeding recommendations, synthesizing evidence on effects of unhealthy food and beverage consumption in children on overweight and obesity. We searched PubMed (Medline), Cochrane CENTRAL, and Embase for articles, irrespective of language or geography. Inclusion criteria were: 1) randomized controlled trials (RCTs), non-RCTs, cohort studies, and pre/post studies with control; 2) participants aged ≤10.9 y at exposure; 3) studies reporting greater consumption of unhealthy foods/beverages compared with no or low consumption; 4) studies assessing anthropometric and/or body composition; and 5) publication date ≥1971. Unhealthy foods and beverages were defined using nutrient- and food-based approaches. Risk of bias was assessed using the ROBINS-I (risk of bias in nonrandomized studies of interventions version I) and RoB2 [Cochrane RoB (version 2)] tools for nonrandomized and randomized studies, respectively. Narrative synthesis was complemented by meta-analyses where appropriate. Certainty of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation. Of 26,542 identified citations, 60 studies from 71 articles were included. Most studies were observational (59/60), and no included studies were from low-income countries. The evidence base was low quality, as assessed by ROBINS-I and RoB2 tools. Evidence synthesis was limited by the different interventions and comparators across studies. Evidence indicated that consumption of sugar-sweetened beverages (SSBs) and unhealthy foods in childhood may increase BMI/BMI z-score, percentage body fat, or odds of overweight/obesity (low certainty of evidence). Artificially sweetened beverages and 100% fruit juice consumption make little/no difference to BMI, percentage body fat, or overweight/obesity outcomes (low certainty of evidence). Meta-analyses of a subset of studies indicated a positive association between SSB intake and percentage body fat, but no association with change in BMI and BMI z-score. High-quality epidemiological studies that are designed to assess the effects of unhealthy food consumption during childhood on risk of overweight/obesity are needed to contribute to a more robust evidence base upon which to design policy recommendations. This protocol was registered at https://www.crd.york.ac.uk/PROSPERO as CRD42020218109.

Screen time increases overweight and obesity risk among adolescents: a systematic review and dose-response meta-analysis

Background

Adolescence is a critical period in human life, associated with reduced physical activity and increased sedentary behaviors. In this systematic review and dose-response meta-analysis, we evaluated the association between screen time and risk of overweight/obesity among adolescents.

Methods

A systematic search in electronic databases, including PubMed, Embase, and Scopus was performed up to September 2021. All published studies evaluating the association between screen time and risk of overweight/obesity among adolescents were retrieved. Finally, a total of 44 eligible studies were included in the meta-analysis.

Results

The results of the two-class meta-analysis showed that adolescents at the highest category of screen time were 1.27 times more likely to develop overweight/obesity (OR = 1.273; 95% CI = 1.166–1.390; P < 0.001; I-squared (variation in ES attributable to heterogeneity) = 82.1%). The results of subgrouping showed that continent and setting were the possible sources of heterogeneity. Moreover, no evidence of non-linear association between increased screen time and risk of overweight/obesity among adolescents was observed (P-nonlinearity = 0.311).

Conclusion

For the first time, the current systematic review and meta-analysis revealed a positive association between screen time and overweight/obesity among adolescents without any dose-response evidence.

Trial registration

The protocol of the current work has been registered in the PROSPERO system (Registration number: CRD42021233899).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01761-4.

Children's longitudinal bodyweight in Australia: Influence of migrant mothers' long-term residency, attachment to, and level of childhood overweight in country-of-birth

Immigration creates opportunities and imposes constraints associated with acculturation. We used the Australian national longitudinal survey of children aged 2 to 17 to evaluate the influence of mothers' long-term residency in Australia, mothers' attachment to country-of-birth, and macro indicators of childhood overweight environment at mothers' country-of-birth on children's longitudinal bodyweight. Both mothers' long-term exposure to the Australian environment and attachment to country-of-birth were associated with increased children's bodyweight z-scores. The childhood overweight environment in mothers' country-of-birth continued to influence their children's bodyweight after immigration. A better understanding of factors related to mothers' migration and children's bodyweight status is necessary to identify risk factors and migrant sub-groups needing extra support.

Measurement of screen time among young children aged 0-6 years: A systematic review

The impact of screen-based devices on children's health and development cannot be properly understood without valid and reliable tools that measure screen time within the evolving digital landscape. This review aimed to summarize characteristics of measurement tools used to assess screen time in young children; evaluate reporting of psychometric properties; and examine time trends related to measurement and reporting of screen time. A systematic review of articles published in English across three databases from January 2009 to April 2020 was undertaken using PROSPERO protocol (registration: CRD42019132599) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included articles measured screen time as outcome, exposure, or confounder in children 0-6 years. The search identified 35,868 records, 1035 full-text articles were screened for eligibility, and 622 met inclusion criteria. Most measures (60%) consisted of one to three items and assessed duration of screen time on a usual day. Few measures assessed content (11%) or coviewing (7%). Only 40% of articles provided a citation for the measure, and only 69 (11%) reported psychometric properties-reliability n = 58, validity n = 19, reliability and validity n = 8. Between 2009 and 2019, the number of published articles increased from 28 to 71. From 2015, there was a notable increase in the proportion of articles published each year that assessed exposure to mobile devices in addition to television. The increasing number of published articles reflects increasing interest in screen time exposure among young children. Measures of screen time have generally evolved to reflect children's contemporary digital landscape; however, the psychometric properties of measurement tools are rarely reported. There is a need for improved measures and reporting to capture the complexity of children's screen time exposures.

Food Insecurity and Major Diet-Related Morbidities in Migrating Children: A Systematic Review

Children of migrant families are known to be at a higher risk of diet-related morbidities due to complex variables including food insecurity, cultural and religious beliefs, and sociodemographic factors like ethnicity, socioeconomic status, and education. Several studies have assessed the presence of specific diseases related to dietary issues in migrant children. This systematic review aims to highlight the existing body of work on nutritional deficiencies in the specific vulnerable pediatric population of immigrants. Refugees were intentionally excluded because of fundamental differences between the two groups including the reasons for migration and health status at the time of arrival. A total of 29 papers were included and assessed for quality. Most of them described a strong correlation between obesity and migration. A high prevalence of stunting, early childhood caries, iron and vitamin D deficiency was also reported, but the studies were few and heterogeneous. Food insecurity and acculturation were found important social factors (nevertheless with inconclusive results) influencing dietary habits and contributing to the development of morbidities such as obesity and other metabolic disorders, which can cause progressive unsustainability of health systems. Public health screening for diet-related diseases in migrant children may be implemented. Educational programs to improve children’s diet and promote healthy-living behaviors as a form of socioeconomic investment for the health of the new generations may also be considered.

BMI trajectories and risk factors among 2-11-year-old children by their immigrant status: evidence from the Longitudinal Study of Australian Children

OBJECTIVE

This study aimed to identify body mass index (BMI) trajectories and their predictors in Australian children by their maternal immigrant status.

METHODS

Data on 4142 children aged 2-3 years were drawn from the birth cohort of the Longitudinal Study of Australian Children. BMI was calculated according to the International Obesity Task Force cut-off points. Immigrant status was determined by the Australian Bureau of Statistics and the United Nations Development Programme, Human Development Index criteria. Latent class growth analysis estimated distinct BMI trajectories, and multinomial logistic regression analysis examined factors associated with these BMI trajectories.

RESULTS

Two BMI groups and six BMI trajectories were identified. The stable trajectories group included high-risk (10%, n=375), moderate-risk (5%, n=215) and low-risk (68%, n=2861) BMI trajectories. The changing trajectories group included delayed-risk (6%, n=234), gradual-risk (8%, n=314) and declining-risk (3%, n=143) BMI trajectories. We found some evidence that children of immigrants from low-and middle-income countries were more likely to have moderate-risk and high-risk BMI trajectories compared with low-risk BMI trajectory. However, these associations were insignificant in fully adjusted models. The explanatory risk factors for moderate-risk and high-risk BMI trajectory were birth weight, family socioeconomic position, and organised sports participation. Our results also suggest that 4-7 years of age may be important for the prevention of overweight/obesity in children.

DISCUSSION

A better understanding of the risk factors associated with distinct BMI trajectories in immigrant children will inform effective preventive strategies. Some of these risk factors such as non-participation in organised sports, and high screen time, may also impede the integration of immigrant children into the host culture. Obesity prevention strategies aimed at increasing physical activities in immigrant children could help deliver a social and health benefit by increasing social integration among children of immigrants and Australians.