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This Review describes current knowledge on the epidemiology and causes of child and adolescent obesity, considerations for assessment, and current management approaches. Before the COVID-19 pandemic, obesity prevalence in children and adolescents had plateaued in many high-income countries despite levels of severe obesity having increased. However, in low-income and middle-income countries, obesity prevalence had risen. During the pandemic, weight gain among children and adolescents has increased in several jurisdictions. Obesity is associated with cardiometabolic and psychosocial comorbidity as well as premature adult mortality. The development and perpetuation of obesity is largely explained by a bio-socioecological framework, whereby biological predisposition, socioeconomic, and environmental factors interact together to promote deposition and proliferation of adipose tissue. First-line treatment approaches include family-based behavioural obesity interventions addressing diet, physical activity, sedentary behaviours, and sleep quality, underpinned by behaviour change strategies. Evidence for intensive dietary approaches, pharmacotherapy, and metabolic and bariatric surgery as supplemental therapies are emerging; however, access to these therapies is scarce in most jurisdictions. Research is still needed to inform the personalisation of treatment approaches of obesity in children and adolescents and their translation to clinical practice.

The prevalence of child and adolescent obesity has plateaued at high levels in most high-income countries and is increasing in many low-income and middle-income countries. Obesity arises when a mix of genetic and epigenetic factors, behavioural risk patterns and broader environmental and sociocultural influences affect the two body weight regulation systems: energy homeostasis, including leptin and gastrointestinal tract signals, operating predominantly at an unconscious level, and cognitive–emotional control that is regulated by higher brain centres, operating at a conscious level. Health-related quality of life is reduced in those with obesity. Comorbidities of obesity, including type 2 diabetes mellitus, fatty liver disease and depression, are more likely in adolescents and in those with severe obesity. Treatment incorporates a respectful, stigma-free and family-based approach involving multiple components, and addresses dietary, physical activity, sedentary and sleep behaviours. In adolescents in particular, adjunctive therapies can be valuable, such as more intensive dietary therapies, pharmacotherapy and bariatric surgery. Prevention of obesity requires a whole-system approach and joined-up policy initiatives across government departments. Development and implementation of interventions to prevent paediatric obesity in children should focus on interventions that are feasible, effective and likely to reduce gaps in health inequalities.

Background/objectives Few quality intervention studies have assessed whether a combined telephone and short message service (SMS) intervention to mothers is effective in reducing BMI and obesity risk behaviors of children at 3 years of age. This study aimed to assess effectiveness of telephone and SMS support in reducing children’s body mass index (BMI) and obesity risk behaviors. Subjects/Methods A randomized controlled trial (RCT) with 662 women of 2-year-old children (with the proportion of overweight and obesity being similar to the general population) was conducted in Sydney, Australia, March 2019–October 2020. The mothers in the intervention group received three telephone support sessions plus SMS messages and mailed-intervention-booklets over a 12 months period i.e., 24–26, 28–30, and 32–34 months of the child’s age. Mothers in the control group received usual care and two mailed booklets on information not related to the intervention. The primary outcome was child’s BMI at 3 years of age. Secondary outcomes were children’s dietary and activity behaviors. All outcome measures were based on mothers’ self-report using standardized tools due to COVID-19 pandemic restrictions. Results 537 (81%) mothers completed the post-intervention assessment at 3 years with only 470 (71%) children having weight and height measures. Multiple imputation analysis showed no statistically significant difference in mean BMI between the groups. Children in the intervention group were more likely not to eat in front of the TV [AOR 1.79 (95% CI 1.17–2.73), P = 0.008], more likely to meet the dietary recommendations [AOR 1.73 (95% CI 0.99–3.02), P = 0.054] and meet the activity recommendations [AOR 1.72 (95% CI 1.11–2.67), P = 0.015] than those in the control group respectively. Among those with an annual household income (−2] in the intervention group than [16.84 (SD 2.37)] in the control, a difference of −0.59 kg/m2 (95% CI: −1.15 to −0.03, P = 0.040). Conclusions A staged telephone and SMS support intervention to mothers with children aged 2 years was associated with improved dietary and activity behaviors. The intervention was also associated with reduced children’s BMI at age 3 years only for those from lower income households. Trial registration The trial is registered with the Australian Clinical Trial Registry (ACTRN12618001571268)

Aim To explore the implementation of a whole-of-government strategy as a policy tool for the early prevention of childhood obesity in New South Wales (NSW), Australia. Subject and methods This paper presents a case study of childhood obesity prevention in the context of implementing the NSW Healthy Eating and Active Living (HEAL) Strategy. We undertook reflexive thematic analysis of interviews with senior officials (n = 25) and content analysis of policy mapping across the NSW Government. Results HEAL was dominated by approaches focused on health services and settings and few environmental actions were undertaken. Four themes were identified: (1) making good citizens, (2) narrowing the scope of prevention, (3) competing government interests and (4) limited collaborative mechanisms. We additionally identified a cross-cutting theme around the expressed need for more evidence. Conclusion Ultimately the HEAL Strategy provided a comprehensive framework with the potential to prevent obesity in early childhood, but it lacked commitment from leadership and willingness across agencies to ensure collaboration on its most contentious areas, notably food environments.

Background/objectives Childhood overweight and obesity are influenced by a range of prenatal and postnatal factors. Few studies have explored the integrative pathways linking these factors and childhood overweight. This study aimed to elucidate the integrative pathways through which maternal pre-pregnancy body mass index (BMI), infant birth weight, breastfeeding duration, and rapid weight gain (RWG) during infancy are associated with overweight outcomes in early childhood from ages 3 to 5 years. Subjects/methods Pooled data from seven Australian and New Zealand cohorts were used (n = 3572). Generalized structural equation modelling was used to examine direct and indirect associations of maternal pre-pregnancy BMI, infant birth weight, breastfeeding duration, and RWG during infancy with child overweight outcomes (BMI z-score and overweight status). Results Maternal pre-pregnancy BMI was directly associated with infant birth weight (β 0.01, 95%CI 0.01, 0.02), breastfeeding duration ≥6 months (OR 0.92, 95%CI 0.90, 0.93), child BMI z-score (β 0.03, 95%CI 0.03, 0.04) and overweight status (OR 1.07, 95%CI 1.06, 1.09) at ages 3–5 years. The association between maternal pre-pregnancy BMI and child overweight outcomes was partially mediated by infant birth weight, but not RWG. RWG in infancy exhibited the strongest direct association with child overweight outcomes (BMI z-score: β 0.72, 95%CI 0.65, 0.79; overweight status: OR 4.49, 95%CI 3.61, 5.59). Infant birth weight was implicated in the indirect pathways of maternal pre-pregnancy BMI with RWG in infancy, breastfeeding duration, and child overweight outcomes. The associations between breastfeeding duration (≥6 months) and lower child overweight outcomes were fully mediated by RWG in infancy. Conclusions Maternal pre-pregnancy BMI, infant birth weight, breastfeeding duration and RWG in infancy act in concert to influence early childhood overweight. Future overweight prevention interventions should target RWG in infancy, which showed the strongest association with childhood overweight; and maternal pre-pregnancy BMI, which was implicated in several pathways leading to childhood overweight.

The cornerstone of obesity treatment is behavioural weight management, resulting in significant improvements in cardio-metabolic and psychosocial health. However, there is ongoing concern that dietary interventions used for weight management may precipitate the development of eating disorders. Systematic reviews demonstrate that, while for most participants medically supervised obesity treatment improves risk scores related to eating disorders, a subset of people who undergo obesity treatment may have poor outcomes for eating disorders. This review summarises the background and rationale for the formation of the Eating Disorders In weight-related Therapy (EDIT) Collaboration. The EDIT Collaboration will explore the complex risk factor interactions that precede changes to eating disorder risk following weight management. In this review, we also outline the programme of work and design of studies for the EDIT Collaboration, including expected knowledge gains. The EDIT studies explore risk factors and the interactions between them using individual-level data from international weight management trials. Combining all available data on eating disorder risk from weight management trials will allow sufficient sample size to interrogate our hypothesis: that individuals undertaking weight management interventions will vary in their eating disorder risk profile, on the basis of personal characteristics and intervention strategies available to them. The collaboration includes the integration of health consumers in project development and translation. An important knowledge gain from this project is a comprehensive understanding of the impact of weight management interventions on eating disorder risk.

What is this summary about? This is a summary of a research survey called ACTION Teens. In our survey, 12,987 people from 10 countries answered questions about obesity. They were: 5275 teenagers with obesity, 5389 caregivers of teenagers with obesity, and 2323 doctors who provide medical care for teenagers with obesity. What were the main results of the survey? Most teenagers with obesity were worried about their weight and thought that losing weight was their responsibility. Many teenagers had already tried to lose weight. For teenagers, wanting to be more fit or in better shape was the top reason for wanting to lose weight. Some caregivers did not realize how worried their teenager was about their own weight. There were also some caregivers who were not aware of their teenager's recent attempts to lose weight. As a group, the doctors did not know the main reasons why teenagers want to lose weight. They also did not know the main reasons preventing teenagers from losing weight. What do the results of the survey mean? Teenagers with obesity will be better supported and understood if there is better communication between teenagers, caregivers, and doctors. Clinical Trial Registration : NCT05013359 ( ClinicalTrials.gov )

The Eating Disorders In weight-related Therapy (EDIT) Collaboration brings together data from randomised controlled trials of behavioural weight management interventions to identify individual participant risk factors and intervention strategies that contribute to eating disorder risk. We present a protocol for a systematic review and individual participant data (IPD) meta-analysis which aims to identify participants at risk of developing eating disorders, or related symptoms, during or after weight management interventions conducted in adolescents or adults with overweight or obesity. We systematically searched four databases up to March 2022 and clinical trials registries to May 2022 to identify randomised controlled trials of weight management interventions conducted in adolescents or adults with overweight or obesity that measured eating disorder risk at pre- and post-intervention or follow-up. Authors from eligible trials have been invited to share their deidentified IPD. Two IPD meta-analyses will be conducted. The first IPD meta-analysis aims to examine participant level factors associated with a change in eating disorder scores during and following a weight management intervention. To do this we will examine baseline variables that predict change in eating disorder risk within intervention arms. The second IPD meta-analysis aims to assess whether there are participant level factors that predict whether participation in an intervention is more or less likely than no intervention to lead to a change in eating disorder risk. To do this, we will examine if there are differences in predictors of eating disorder risk between intervention and no-treatment control arms. The primary outcome will be a standardised mean difference in global eating disorder score from baseline to immediately post-intervention and at 6- and 12-months follow-up. Identifying participant level risk factors predicting eating disorder risk will inform screening and monitoring protocols to allow early identification and intervention for those at risk.

Background When tackling complex public health challenges such as childhood obesity, interventions focused on immediate causes, such as poor diet and physical inactivity, have had limited success, largely because upstream root causes remain unresolved. A priority is to develop new modelling frameworks to infer the causal structure of complex chronic disease networks, allowing disease “on-ramps” to be identified and targeted. Methods The system surrounding childhood obesity was modelled as a Bayesian network, using data from The Longitudinal Study of Australian Children. The existence and directions of the dependencies between factors represent possible causal pathways for childhood obesity and were encoded in directed acyclic graphs (DAGs). The posterior distribution of the DAGs was estimated using the Partition Markov chain Monte Carlo. Results We have implemented structure learning for each dataset at a single time point. For each wave and cohort, socio-economic status was central to the DAGs, implying that socio-economic status drives the system regarding childhood obesity. Furthermore, the causal pathway socio-economic status and/or parental high school levels → parental body mass index (BMI) → child’s BMI existed in over 99.99% of posterior DAG samples across all waves and cohorts. For children under the age of 8 years, the most influential proximate causal factors explaining child BMI were birth weight and parents’ BMI. After age 8 years, free time activity became an important driver of obesity, while the upstream factors influencing free time activity for boys compared with girls were different. Conclusions Childhood obesity is largely a function of socio-economic status, which is manifest through numerous downstream factors. Parental high school levels entangle with socio-economic status, and hence, are on-ramp to childhood obesity. The strong and independent causal relationship between birth weight and childhood BMI suggests a biological link. Our study implies that interventions that improve the socio-economic status, including through increasing high school completion rates, may be effective in reducing childhood obesity prevalence.

Inflammatory diets are increasingly recognised as a modifiable determinant of mental illness. However, there is a dearth of studies in early life and across the full mental well-being spectrum (mental illness to positive well-being) at the population level. This is a critical gap given that inflammatory diet patterns and mental well-being trajectories typically establish by adolescence. We examined the associations of inflammatory diet scores with mental well-being in 11–12-year-olds and mid-life adults. Throughout Australia, 1759 11–12-year-olds (49 % girls) and 1812 parents (88 % mothers) contributed cross-sectional population-based data. Alternate inflammatory diet scores were calculated from a twenty-six-item FFQ, based on the prior literature and prediction of inflammatory markers. Participants reported negatively and positively framed mental well-being via psychosocial health, quality of life and life satisfaction surveys. We used causal inference modelling techniques via generalised linear regression models (mean differences and risk ratios (RR)) to examine how inflammatory diets might influence mental well-being. In children and adults, respectively, a 1 sd higher literature-derived inflammatory diet score conferred between a 44 % (RR 95 % CI 1·2, 1·8) to 57 % (RR 95 % CI 1·3, 2·0) and 54 % (95 % CI 1·2, 2·0) to 86 % (RR 95 % CI 1·4, 2·4) higher risk of being in the worst mental well-being category (i.e.

Eating disorders are complex mental health conditions that share risk factors with obesity. This review outlines the context for concerns that paediatric obesity treatment presents a risk for eating disorder development. Most children and adolescents undergoing professionally supervised obesity treatment will have improvements or no change to eating disorder risk profiles. However, some may subsequently develop a clinical eating disorder, and this is proposed to relate to weight-focussed dietary interventions that are standard in paediatric obesity treatment. Nevertheless, dietary restraint may not be a strong predictor of eating disorder risk in the context of paediatric obesity treatment. Most international guidelines recommend weight maintenance or weight loss as a treatment goal, and weight loss is related to improvements in cardiometabolic health but not eating disorder risk in the short term. The risk of inducing or exacerbating an eating disorder during paediatric weight management is likely to be low; however, the serious consequences combined with increasing scale of obesity treatment, and lack of empirical evidence, are of concern. There is a need for further research to identify long-term predictors of eating disorder development for children and adolescents who seek treatment for their obesity.

Non-dieting approaches, including mindful/intuitive eating, to health improvement are of increasing interest, yet little is known about young adults’ social media exposure to them. Therefore, this study aimed to describe the imagery related to mindful/intuitive eating which is visible to young adult Instagram users. Images categorized under the hashtags ‘mindfuleating’ and ‘intuitiveeating’ were searched in September 2021 using the ‘top posts’ view. Screen captures of 1200 grid-view images per hashtag were used to construct coding frameworks and to determine saturation. Sample sizes for #mindfuleating and #intuitiveeating were 405 and 495 images, respectively. Individual images were coded collaboratively. Almost half of each sample depicted food or drink, of which 50–60% were healthy foods. Approximately 17% were single-person images, of which the majority were young, female adults with healthy weight. Approximately one-third of text suggested credibility through credentials, profession, or evidence. Messaging was similar for both hashtags, encompassing mindful/intuitive eating (~40%), nutrition/eating behaviours (~15%), physical/mental health (~20%), disordered eating (~12%), and body-/self-acceptance (~12%). Differences were observed between hashtags for weight-related concepts (20%/1%) and anti-diet/weight-neutral approaches (10%/35%). The representation on Instagram of mindful and intuitive eating portrays healthy lifestyles without a focus on weight but lacks demographical and body-type diversity. Instagram holds the potential for health professionals to disseminate culturally/demographically inclusive, evidence-based health/nutrition information to youth.

This study aimed to conduct an economic evaluation of the Communicating Healthy Beginnings Advice by Telephone (CHAT) trial to prevent childhood obesity.Cost-effectiveness analyses were conducted for the telephone and short message service (SMS) delivery of Healthy Beginnings advice, compared with usual care, which included child health services unrelated to Healthy Beginnings. Costs were valued in 2018 Australian dollars, and costs and outcomes were discounted at 5% per year. The costs of upscaling both delivery modes to all yearly births in New South Wales, Australia, were estimated and compared with the original Healthy Beginnings home-visiting intervention.At child age 2 years, the SMS delivery was more cost-effective ($5154 per unit BMI and $979 per 0.1 BMI z score units avoided) than the telephone delivery ($10,665 per unit BMI and $2017 per 0.1 BMI z score units avoided). The costs of upscaling the SMS ($7.64 million) and the telephone delivery modes ($37.65 million) were lower than the home-visiting intervention ($108.45 million).SMS delivery of Healthy Beginnings advice was more cost-effective than telephone delivery but less cost-effective than the original home-visiting approach ($4230 per unit BMI avoided, as calculated in an earlier study). Both the SMS and telephone interventions were more affordable than the home-visiting approach.

Aim To identify multi-disciplinary paediatric weight management services currently available in Australia and determine gaps in service provision for children and adolescents with obesity. Methods Surveys were distributed to 17 identified Australian multi-disciplinary paediatric weight management services. A representative from each service was asked to complete an online survey regarding service and patient characteristics, assessment and management practices, and professional development approaches. Results Representatives from 16 multi-disciplinary paediatric weight management services completed the survey. Fourteen services were based in major metropolitan cities and two in regional areas. Fourteen services provided care to pre-school aged children (0-4 years old), 15 to primary school aged children (5-12 years old) and 13 to high school aged children (13-18 years old). The number of patients seen per year per service ranged from 20 to 250 and duration of waiting lists ranged from 2 months to more than 12 months. Conclusions The current availability and accessibility of multi-disciplinary paediatric weight management services is inadequate to service Australian children and adolescents with obesity, particularly those with severe obesity and those in rural and remote communities. To better address the issue of paediatric obesity, establishment of additional multi-disciplinary services, training for health-care professionals and monitoring of the provision of evidence-based care is urgently needed.

BACKGROUND/OBJECTIVE Many studies have shown that child BMI or weight status tracks over time, but the demographic predictors of high tracking have not been investigated. Our objective was to identify demographic predictors of persistence (duration) of healthy weight and overweight/obesity throughout childhood, and to examine whether tracking was age dependent. METHODS We conducted secondary data analysis of 4606 children from the Birth cohort and 4983 children from the Kindergarten cohort of the Longitudinal Study of Australian Children with follow-up to age 12/13 and 16/17 years, respectively. Retrospective and prospective tracking were examined descriptively. Time-to-event analysis determined demographic predictors of persistence of healthy weight and overweight/obesity beyond age 4-5 years, after controlling for child BMI z-score. Weight status was determined using WHO methods. RESULTS Tracking of healthy weight was consistently higher than that of overweight/obesity, and incident overweight was equally likely throughout childhood and adolescence. Tracking of overweight was lower for children under 7 years than in middle childhood and adolescence (2-year probability 65%, compared with 80%; 2-year resolution of overweight 35 and 20%). Children of lower socioeconomic position, those from culturally and linguistically diverse backgrounds, and girls were more likely to move into overweight (hazard ratios [95%CI] for incident overweight: 1.39 [1.26-1.52], 1.16 [1.02-1.31] and 1.12 [1.02-1.23], respectively) and less likely to resolve their overweight (hazard ratios for resolution of overweight/obesity: 0.77 [0.69-0.85], 0.8 [0.69-0.92] and 0.79 [0.71-0.81], respectively) during childhood. However, persistence of weight status was not significantly affected by rurality or Indigenous status (P > 0.05). CONCLUSIONS Lowest tracking and highest natural resolution of overweight in children under 7 years suggests this may be an opportune time for interventions to reduce overweight. Primary and secondary prevention programmes during the school years should be designed with special consideration for lower socioeconomic communities, for culturally and linguistically diverse populations and for girls.

Study objectives: Sleep, physical activity and sedentary time are all known to play a role in cardiometabolic health. Compositional data analysis (CoDA) enables us to examine associations between 24-h use of time and health outcomes. Methods: Data were collected in the Child Health Check Point study, a one-off national population-cohortstudy conducted between February 2015 and March 2016. Wrist-worn actigraphy monitors (GENEActiv Original, Cambs, UK) were used to measure activity behaviours (sleep, physical activity and sedentary time) and sleep characteristics (sleep variability, midsleep, efficiency). CoDA was applied to determine the association between 24-h use of time and cardiometabolic risk markers (blood pressure; body mass index; apolipoprotein B/A1; glycoprotein acetyls; and composite metabolic syndrome score). Substitution modelling (one-for-remaining and one-for-one) examined the associations of reallocating sleep time with other activity behaviours. Results: Data were available for 1073 Australian children aged 11e12 years (50% male) and 1337 adults(13% male). Strong association was found between 24-h use of time and all cardiometabolic health outcomes. Longer sleep was associated with more favourable cardiovascular health. Sleep characteristics other than duration (efficiency, timing, variability) were weakly and inconsistently associated with outcomes. Reallocating time from sleep to moderate-vigorous physical activity (MVPA) had favourable associations with cardiometabolic health, but reallocating from sleep to sedentary time was associated with less favourable cardiometabolic health.Conclusion: The 24-h activity composition is strongly associated with cardiometabolic health in children and adults. Days with more sleep and MVPA are associated with improved cardiometabolic health. Refereed/Peer-reviewed

Background Increasingly, public health interventions are delivered via telephone and/or text messages. Recent systematic reviews of early childhood obesity prevention interventions have not adequately reported on the way interventions are delivered and the experiences/perceptions of stakeholders. We aimed to summarise the literature in early childhood obesity prevention interventions delivered via telephone or text messages for evidence of application of process evaluation primarily to evaluate stakeholders’ acceptability of interventions. Methods A systematic search of major electronic databases was carried out using the Population, Intervention, Comparison, Outcomes framework. Studies were included if interventions were delivered via telephone/text messages; aimed at changing caregivers’ behaviours to prevent early childhood obesity; with one or more outcomes related to early obesity risk factors such as breastfeeding, solid feeding, tummy time, sleep and settling, physical activity and screen time; published from inception to May 2020. All eligible studies were independently assessed by two reviewers using the Cochrane Collaboration tool for assessing risk of bias. Qualitative studies were assessed using the Consolidated Criteria for Reporting Qualitative Research and Standards for Reporting Qualitative Research tools. Results Twenty-four studies were eligible, and the overall risk of bias was low. Eight studies (33%) had evidence of process evaluation that examined participants’ perceptions of interventions. Participants appreciated the convenience of receiving interventions via telephone or text messages. 63% of all studies in this review showed improvement in one or more behaviours related to childhood obesity prevention. Participants were likely to modify behaviours if they received information from a credible source such as from health professionals. Conclusion There is limited reporting of stakeholders’ experiences in early obesity prevention studies delivered by telephone or text messages. Only one-third of studies examined participants’ acceptability and the potential for delivery of childhood obesity prevention interventions conveniently using this mode of delivery. Interventions delivered remotely via telephone or text messages have the potential to reach equal or a greater number of participants than those delivered via face-to-face methods. Future research should build in process evaluation alongside effectiveness measurements to provide important insight into intervention reach, acceptability and to inform scale up. Trial registration PROSPERO registration: CRD42019108658

BACKGROUND Longitudinal data investigating tracking of children's lifestyle behaviors and predictors of childhood obesity are limited. OBJECTIVES We examined changes in children's lifestyle behaviors (dietary, physical activity, and screen time) from ages 2-5 y to determine if maternal sociodemographic factors and BMI predict child obesity at 3.5 y and 5 y. METHODS Data were obtained from 667 first-time mothers who were recruited into the Healthy Beginnings Trial at 24-34 weeks of gestation in Sydney, Australia. Child lifestyle behaviors were assessed using face-to-face questionnaire interviews with mothers. To measure child and maternal anthropometry, BMI (in kg/m2) was calculated using measured height and weight. Children were categorized as overweight or obese based on the International Obesity Task Force criteria. We used 1-factor repeated-measures ANOVA to track preschoolers' lifestyle behaviors and multiple logistic regression to determine obesity predictors. RESULTS In children aged 2-5 y, consumption of vegetables (ηp2 = 0.06; P

Human body composition is made up of mutually exclusive and exhaustive parts (e.g. %truncal fat, %non-truncal fat and%fat-free mass) which are constrained to sum to the same total (100%). In statistical analyses, individual parts of body composition (e.g. %truncal fat or %fat-free mass) have traditionally been used as proxies for body composition, and have been linked with a range of health outcomes. But analysis of individual parts omits information about the other parts,which are intrinsically co-dependent because of the constant sum constraint of 100%. Further, body mass may be associated with health outcomes. We describe a statistical approach for body composition based on compositional data analysis. The body composition data are expressed as logratios to allow relative information about all the compositional parts to be explored simultaneously in relation to health outcomes. We describe a recent extension to the logratio approach to compositional data analysis which allows absolute information about the total of the compositional parts (body mass) to be considered alongside relative information about body composition. The statistical approach is illustrated by an example that explores the relationships between adults’ body composition, body mass and bone strength. Refereed/Peer-reviewed

There is limited evidence regarding the experiences, challenges, and needs of adolescents living with obesity (ALwO), their caregivers, and healthcare professionals (HCPs).The cross-sectional, survey-based global ACTION Teens study aimed to identify perceptions, attitudes, behaviours, and barriers to effective obesity care among ALwO, caregivers of ALwO, and HCPs.ALwO (aged 12 to18 years; N = 5275), caregivers (N = 5389), and HCPs treating ALwO (N = 2323) from 10 countries completed an online survey (August-December 2021).Most ALwO perceived their weight as above normal (76% vs. 66% of caregivers), were worried about its impact on their health (85% vs. 80% of caregivers), and recently made a weight loss attempt (58%). While 45% of caregivers believed ALwO would slim down with age, only 24% of HCPs agreed. Most commonly reported weight loss motivators for ALwO were wanting to be more fit/in better shape according to ALwO (40%) and caregivers (32%), and improved confidence/social life according to HCPs (69%). ALwO weight loss barriers included lack of hunger control (most commonly reported by ALwO/caregivers), lack of motivation, unhealthy eating habits (most commonly agreed by HCPs), and lack of exercise.Misalignment between ALwO, caregivers, and HCPs-including caregivers' underestimation of the impact of obesity on ALwO and HCPs' misperception of key motivators/barriers for weight loss-suggests a need for improved communication and education.

Background Obesity is an increasing health concern in Australia among adult and child populations alike and is often associated with other serious comorbidities. While the rise in the prevalence of childhood obesity has plateaued in high-income countries, it continues to increase among children from disadvantaged and culturally diverse backgrounds. The family environment of disadvantaged populations may increase the risk of childhood obesity through unhealthy eating and lifestyle practices. The Strong Families Trial aims to assess the effectiveness of a mixed behavioural and lifestyle intervention for parents and carers of at-risk populations, i.e. families from culturally diverse and disadvantaged backgrounds, in preventing unhealthy weight gain among children aged 5 to 11 years. Methods Eight hundred families from low socio-economic areas in Greater Western Sydney, NSW, and Melbourne, VIC, will be recruited and randomised into a lifestyle intervention or control group. The intervention comprises 90-minute weekly sessions for 6 weeks (plus two-booster sessions) of an integrated, evidence-based, parenting and lifestyle program that accounts for the influences of family functioning. Primary (anthropometric data) and secondary (family functioning, feeding related parenting, physical activity, consumption of healthy foods, health literacy, family and household costs) outcome measures will be assessed at baseline, immediately following the intervention, and 12 months post-intervention. Discussion This study will elucidate methods for engaging socially disadvantaged and culturally diverse groups in parenting programs concerned with child weight status. Trial Registration This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12619001019190). Registered 16 July 2019.

Rapid weight gain (RWG) in infancy is strongly associated with subsequent obesity risk, but little is known about the factors driving RWG. This study explored the child and maternal factors associated with infant RWG.Data from seven Australian and New Zealand cohorts were used (n = 4542). Infant RWG was defined as a change in weight z-score ≥0.67 from birth to age 1 year. Univariable and multivariable logistic regression assessed the association between child and maternal factors and infant RWG in each cohort. Meta-analysis was conducted to obtain pooled effect sizes.Multivariable analyses revealed boys were more likely to experience RWG (OR 1.42 95% CI 1.22, 1.66) than girls. Higher birth weight in kg (OR 0.09, 95% CI 0.04, 0.20) and gestational age in weeks (OR 0.69, 95% CI 0.48, 0.98) were associated with lower RWG risk. Children who were breastfed for ≥6 months showed lower RWG risk (OR 0.45, 95% CI 0.38, 0.53). Children of native-born versus overseas-born women appeared to have higher RWG risk (OR 1.37, 95% CI 0.99, 1.90). Maternal smoking during pregnancy increased RWG risk (OR 1.60, 95% CI 1.28, 2.01), whereas children who started solids ≥6 months (OR 0.77, 95% CI 0.63, 0.93) and children with siblings (OR 0.68, 95% CI 0.57, 0.81) showed lower RWG risk in univariable analysis, but these associations were attenuated in multivariable analysis. No association was found for maternal age, education, marital status and pre-pregnancy BMI.Maternal country of birth, smoking status, child sex, birth weight, gestational age, infant feeding and parity were potential determinants of infant RWG.

IntroductionBehavioural interventions in early life appear to show some effect in reducing childhood overweight and obesity. However, uncertainty remains regarding their overall effectiveness, and whether effectiveness differs among key subgroups. These evidence gaps have prompted an increase in very early childhood obesity prevention trials worldwide. Combining the individual participant data (IPD) from these trials will enhance statistical power to determine overall effectiveness and enable examination of intervention-covariate interactions. We present a protocol for a systematic review with IPD meta-analysis to evaluate the effectiveness of obesity prevention interventions commencing antenatally or in the first year after birth, and to explore whether there are differential effects among key subgroups.Methods and analysisSystematic searches of Medline, Embase, CENTRAL, CINAHL, PsycInfo, and trial registries for all ongoing and completed randomised controlled trials evaluating behavioural interventions for the prevention of early childhood obesity have been completed up to March 2020 and will be updated annually to include additional trials. Eligible trialists will be asked to share their IPD; if unavailable, aggregate data will be used where possible. An IPD meta-analysis and a nested prospective meta-analysis (PMA) will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index (BMI) z-score at age 24 +/- 6 months using World Health Organisation Growth Standards, and effect differences will be explored among pre-specified individual and trial-level subgroups. Secondary outcomes include other child weight-related measures, infant feeding, dietary intake, physical activity, sedentary behaviours, sleep, parenting measures and adverse events.Ethics and disseminationApproved by The University of Sydney Human Research Ethics Committee (2020/273) and Flinders University Social and Behavioural Research Ethics Committee (project no. HREC CIA2133-1). Results will be relevant to clinicians, child health services, researchers, policy-makers and families, and will be disseminated via publications, presentations, and media releases.RegistrationProspectively registered on PROSPERO: CRD42020177408STRENGTHS AND LIMITATIONS OF THIS STUDYThis will be the largest individual participant data (IPD) meta-analysis evaluating behavioural interventions for the prevention of early childhood obesity to date, and will provide the most reliable and precise estimates of early intervention effects to inform future decision-making.IPD meta-analysis methodology will enable unprecedented exploration of important individual and trial-level characteristics that may be associated with childhood obesity or that may be effect modifiers.The proposed innovative methodologies are feasible and have been successfully piloted by members of our group.It may not be possible to obtain IPD from all eligible trials; in this instance, aggregate data will be used where available, and sensitivity analyses will be conducted to assess inclusion bias.Outcome measures may be collected and reported differently across included trials, potentially increasing imprecision; however, we will harmonise available data where possible, and encourage those planning or conducting ongoing trials to collect common core outcomes following prospective meta-analysis methodology.

IntroductionLittle is known about how early (e.g., commencing antenatally or in the first 12 months after birth) obesity prevention interventions seek to change behaviour and which components are or are not effective. This study aims to 1) characterise early obesity prevention interventions in terms of target behaviours, delivery features, and behaviour change techniques (BCTs), 2) explore similarities and differences in BCTs used to target behaviours, and 3) explore effectiveness of intervention components in preventing childhood obesity.Methods and analysisAnnual comprehensive systematic searches will be performed in Epub Ahead of Print/MEDLINE, Embase, Cochrane (CENTRAL), CINAHL, PsycINFO, as well as clinical trial registries. Eligible randomised controlled trials of behavioural interventions to prevent childhood obesity commencing antenatally or in the first year after birth will be invited to join the TOPCHILD Collaboration. Standard ontologies will be used to code target behaviours, delivery features and BCTs in both published and unpublished intervention materials provided by trialists. Narrative syntheses will be performed to summarise intervention components and compare applied BCTs by types of target behaviours. Exploratory analyses will be undertaken to assess effectiveness of intervention components.Ethics and disseminationThe study has been approved by The University of Sydney Human Research Ethics Committee (project no. 2020/273) and Flinders University Social and Behavioural Research Ethics Committee (project no. HREC CIA2133-1). The study’s findings will be disseminated through peer-reviewed publications, conference presentations, and targeted communication with key stakeholders.DiscussionOur study will provide an in depth understanding of behavioural components and delivery features used in obesity prevention interventions starting antenatally or in the first 12 months after birth. Understanding common intervention approaches in a systematic way will provide much needed insight to advance the design of early obesity prevention interventions and provide the opportunity to undertake future quantitative predictive modelling.RegistrationPROSPERO registration no. CRD42020177408STRENGTHS AND LIMITATIONS OF THIS STUDYThis study provides an understanding of behaviours targeted, behaviour change techniques and delivery features used in early childhood obesity prevention trials identified in a systematic review as being eligible for inclusion in the Transforming Obesity Prevention in CHILDren (TOPCHILD) Collaboration.Extends previous methods by coding behaviour change techniques in published and unpublished intervention materials and performing cross validation with trialists through the TOPCHILD Collaboration.Using standardised coding taxonomies will allow for comparisons across studies, and we will pilot test new ontologies from the Human Behaviour Change Project.Explores the complex area of targeting parent and caregivers’ behaviours to impact child outcomes across four key obesity prevention behavioural domains (relating to infant feeding practices, food provision and parent feeding practices, movement practices, sleep health practices).This study will provide preliminary results regarding the examination of intervention components’ effectiveness based on exploratory analysis. Yet, the internationally unique database this project creates will further our understanding of effective intervention components in future research.To date we already have 38 out of 65 eligible trials agreeing to share data, since not all trials may provide unpublished material we may perform sensitivity analyses comparing trials that have shared data to trials that have not shared materials.