Family systems approaches in pediatric obesity management: a scoping review.

Family-based obesity management interventions targeting child, adolescent and parental lifestyle behaviour modifications have shown promising results. Further intervening on the family system may lead to greater improvements in obesity management outcomes due to the broader focus on family patterns and dynamics that shape behaviours and health. This review aimed to summarize the scope of pediatric obesity management interventions informed by family systems theory (FST). Medline, Embase, CINAHL and PsycInfo were searched for articles where FST was used to inform pediatric obesity management interventions published from January 1980 to October 2023. After removal of duplicates, 6053 records were screened to determine eligibility. Data were extracted from 50 articles which met inclusion criteria; these described 27 unique FST-informed interventions. Most interventions targeted adolescents (44%), were delivered in outpatient hospital settings (37%), and were delivered in person (81%) using group session modalities (44%). Professionals most often involved were dieticians and nutritionists (48%). We identified 11 FST-related concepts that guided intervention components, including parenting skills, family communication, and social/family support. Among included studies, 33 reported intervention effects on at least one outcome, including body mass index (BMI) (n = 24), lifestyle behaviours (physical activity, diet, and sedentary behaviours) (n = 18), mental health (n = 12), FST-related outcomes (n = 10), and other outcomes (e.g., adiposity, cardiometabolic health) (n = 18). BMI generally improved following interventions, however studies relied on a variety of comparison groups to evaluate intervention effects. This scoping review synthesises the characteristics and breadth of existing FST-informed pediatric obesity management interventions and provides considerations for future practice and research.

Associations Between Weight-Loss Attempts, Weight-Related Stress, and Body Image During Childhood and Adolescence in Children With Parental Obesity.

Background: Few longitudinal studies have investigated the role of weight-loss attempts or weight-related stress on body image during childhood. We examined whether weight-loss attempts and weight-related stress are associated with weight misperception and body dissatisfaction across childhood and adolescence. Methods: Data were drawn from the Quebec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort of Canadian children with parental obesity (8-10 years: n = 630; 10-12 years: n = 564; 15-17 years: n = 377). We assessed weight-loss attempts and weight-related stress at baseline and first follow-up, and perceived and desired silhouettes at first and second follow-up with questionnaires. Weight misperception consisted of the difference in BMI z-score (zBMI) from the perceived silhouette and the measured zBMI. Body dissatisfaction consisted of the discordance between perceived and desired silhouettes. We estimated multivariable mixed-effects regression models adjusting for age, sex, pubertal stage, parental BMI and education, and sport-based teasing. Results: Weight loss attempts were associated with a higher weight misperception score (ever tried, beta [95% confidence intervals; CI]: 0.13 [0.01-0.24]) and with 2.13 times higher desire to be thinner (95% CI: 1.39-3.26) at the subsequent follow-up. Similarly, children stressed by their weight had a higher misperception score (beta [95% CI]: 0.15 [0.02-0.27]) and greater desire to be thinner at the next follow-up (odds ratio [95% CI]: 1.73 [0.999-3.00]). Conclusions: Weight-loss attempts and weight-related stress in children and adolescents are associated with weight misperception and body dissatisfaction, supporting empowerment and counseling focusing on healthy eating behaviors and a positive body image. Clinical Trial Registration Number: NCT03356262.

Early Lifestyle Determinants of Adiposity Trajectories from Childhood into Late Adolescence.

Objective: The aim of this study was to examine associations of childhood physical activity, sedentary behavior, and dietary intake with adiposity trajectories from childhood to adolescence. Methods: Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort (n = 630) data from 3 time points (8-10, 10-12, and 15-17 years) for 377 Caucasian children with parental obesity were analyzed. Height and weight, physical activity and sedentary behavior (7-day accelerometry), screen time (self-reported), and dietary intake (three 24-hour diet recalls) were measured. Group-based trajectory modeling identified longitudinal trajectories of body-mass index z-scores (zBMIs). Inverse probability of exposure-weighted multinomial logistic regressions examined associations between baseline lifestyles and zBMI trajectory groups. Results: Six trajectory groups were identified: Stable-Low-Normal-Weight (two groups, 5.7% and 33.0%, which were combined), Stable-High-Normal-Weight (24.8%), Stable-Overweight (19.8%), Stable-Obesity (8.8%), and Overweight-Decreasers (7.9%). For every additional portion of fruits and vegetables, the likelihood of being in the group of Overweight-Decreasers increased by 29% (odds ratio [OR]: 1.29, 95% confidence interval [CI]: 1.09-1.55) compared with the reference group (Stable-Low-Normal-Weight). For every additional hour of sedentary behavior, the likelihood of belonging to the group of Overweight-Decreasers increased 2-fold (OR: 1.99, 95% CI: 1.28-3.21) and Stable-Obesity increased 1.5-fold (OR: 1.56, 95% CI: 1.08-2.23), compared with the reference. Every additional 10 minutes of moderate-to-vigorous physical activity was associated with a lower likelihood of belonging to the Stable-Obesity group (OR: 0.75, 95% CI: 0.61-0.89) and to the group of Overweight-Decreasers (OR: 0.79, 95% CI: 0.64-0.95) compared with the reference. Finally, children were more likely to belong to the Stable-Obesity group with each additional hour/day of screen time (OR: 1.23, 95% CI: 1.01-1.58). Conclusions: Trajectories of zBMIs from childhood to late adolescence were stable, except for one group which decreased from overweight in childhood to normal weight in adolescence. The latter had more favorable baseline dietary intake of fruits and vegetables. ClinicalTrials.org no. NCT03356262.

Prevalence and determinants of overweight and obesity among preschool-aged children from migrant and socioeconomically disadvantaged contexts in Montreal, Canada.

Among migrant and socioeconomically disadvantaged preschool-aged children followed in social perinatal primary care services in Montreal, Canada, we estimated the prevalence of overweight/obesity and identified determinants of body mass index z-score (zBMI) at 4-5 years old. We conducted a retrospective cohort study using electronic medical records of 275 child-mother dyads followed from birth to 4-5 years. Anthropometric measures and established maternal, perinatal and child risk factors for childhood obesity were examined. Age- and sex-specific zBMI at 4-5-years were computed and categorized according to WHO standards. Linear regression with model averaging was used to identify early life factors associated with zBMI. At 4-5 years, children's weight status was classified as underweight (1.5%), normal weight (69.7%), at-risk-of-overweight (19.2%), overweight (6.9%), and obesity (2.7%). Primiparity (0.51, 95% CI 0.24; 0.78), higher birthweight (1.04, 95% CI 0.70; 1.37), accelerated weight gain in the first year of life (0.21, 95% CI 0.13; 0.31), and introduction to solid foods before 6 months (0.89, 95% CI 0.42; 1.36) were associated with a higher zBMI, while less than high school education (-0.50, 95% CI -0.95; -0.05) and higher gestational age (-0.14, 95% CI -0.21; -0.05) were associated with lower zBMI at 4-5 years. Overweight/obesity is prevalent among preschool-aged children from migrant and socioeconomically disadvantaged contexts and is associated with known risk factors. Future research is needed to better understand the role of social perinatal primary care services in promoting optimal weight gain among children living in contexts of vulnerability.

The longitudinal effects of maternal parenting practices on children's body mass index z-scores are lagged and differential.

BACKGROUND: The longitudinal relation between parenting practices and styles with children's body mass index z-scores (zBMI) is poorly understood. Previous studies suggest the relationship may be complex, but small samples and short follow-ups diminish the strength of the evidence. The objectives of this study were to investigate whether the relationship is bidirectional, time-varying, and lagged using data from a large, representative birth cohort of Quebec children. METHODS: Data were from the Québec Longitudinal Study of Child Development (QLSCD), a prospective birth cohort (n = 1,602). The mothers' interactions with their children (at ages 6, 8, 10, and 12 years) were utilized in factor analysis to identify three latent parenting practices (disciplinarian, lenient, and responsive). The parenting practices were analyzed with K-means clustering to identify the parenting styles. The temporal and bidirectional relationships were assessed in a cross-lagged path analysis using a structural equation modelling framework. Mixed models controlling for age, sex, income, mother's education, and whether the participant was first-born were estimated. Missing data were handled with full information maximum likelihood. RESULTS: From the linear mixed models, greater lenient and responsive parenting practices were associated with higher zBMI (B = 0.03, p < 0.05) two years later. However, there was no evidence that the relationship was bidirectional nor that parenting style was predictive of children's zBMI. CONCLUSION: While mothers' parenting practices were unaffected by their children's zBMI, parental practices were predictive of future zBMI among their prepubertal children. More in-depth exploration of parenting practices and their potential impact on pediatric weight is needed.

Adolescents' reports of chaos within the family home environment: Investigating associations with lifestyle behaviours and obesity.

OBJECTIVE: Disorganised and chaotic home environments may hinder the adoption of healthy lifestyle behaviours and contribute to excessive weight gain among adolescents. We examined whether self-reported level of chaos within the family home environment is associated with lifestyle behaviours and obesity in adolescent girls and boys. METHODS: Cross-sectional data from the 3rd wave of the Québec Adipose and Lifestyle Investigation in Youth (QUALITY) study were analyzed. The sample consisted of n = 377 White adolescents with a history of parental obesity. Home environment chaos was measured using the Confusion, Hubbub, and Order Scale (CHAOS) analyzed both continuously and dichotomized as high vs. low chaos. Body Mass Index z-scores (zBMI) were computed using WHO standards from measured weight and height. Physical activity (7-day accelerometry), vegetable and fruit intake (three 24-hour diet recalls), and leisure screen time and sleep duration (questionnaire) were assessed. Sex-specific linear regression models were used to estimate associations between level of family home environment chaos, lifestyle behaviours and zBMI. RESULTS: The overall level of chaos was low in our study sample, with higher reported levels among girls compared to boys. Among girls, high (vs low) chaos was associated with shorter sleep duration (hours/day) (B = - 0.44, 95% CI: -0.75, -0.14). No associations were observed for other lifestyle behaviours or for zBMI. CONCLUSION: In this sample of adolescents with a parental history of obesity, higher household chaos was not associated with obesity or lifestyle behaviours, except for sleep duration among girls. Replication of findings in more diverse samples is indicated.

Estimating causal effects of physical activity and sedentary behaviours on the development of type 2 diabetes in at-risk children from childhood to late adolescence: an analysis of the QUALITY cohort.

BACKGROUND: Uncertainty remains regarding the causal effect of physical activity and sedentary behaviours on the development of type 2 diabetes in children. We aimed to estimate average treatment effects of physical activity and sedentary behaviours on risk of type 2 diabetes in individuals who are at risk during childhood and adolescence. METHODS: We used data from the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort of children of western European descent (white non-Hispanic race or ethnicity) with a parental history of obesity (defined as a BMI of 30 kg/m2 or more, or a waist circumference of more than 102 cm in men and 88 cm in women) evaluated at the ages of 8-10 years (baseline), 10-12 years (first follow-up cycle), and 15-17 years (second follow-up cycle) in Québec, Canada. We measured moderate-to-vigorous physical activity (MVPA) and sedentary time by accelerometry, and leisure screen time by questionnaire at each cycle. Outcomes included fasting and 2 h post-load glycaemia and validated indices of insulin sensitivity and insulin secretion. We estimated average treatment effects of MVPA, sedentary time, and screen time on markers of type 2 diabetes using longitudinal marginal structural models with time-varying exposures, outcomes, and confounders from the ages of 8-10 to 15-17 years and inverse probability of treatment and censoring weighting. We considered both the current and cumulative effects of exposures on outcomes. FINDINGS: 630 children were evaluated at baseline (age 8-10 years) between July, 2005, and December, 2008, 564 were evaluated at the first follow-up (age 10-12 years) between July, 2007, and March, 2011, and 377 were evaluated at the second follow-up (age 15-17 years) between September, 2012, and May, 2016. Based on cumulative exposure results, estimated average treatment effects for MVPA were 5·6% (95% CI 2·8 to 8·5) on insulin sensitivity and -3·8% (-7·1 to -0·5) on second-phase insulin secretion per 10 min daily increment from the ages of 8-10 years to age 15-17 years. Average treatment effects for sedentary time and reported screen time resulted in reduced insulin sensitivity (-8·2% [-12·3 to -3·9] and -6·4% [-10·1 to -2·5], respectively), increased second-phase insulin secretion (5·9% [1·9 to 10·1] and 7·0% [-0·1 to 14·7], respectively), and higher fasting glycaemia (0·03 mmol/L [0·003 to 0·05] and 0·02 mmol/L [0·01 to 0·03], respectively) per additional daily hour from the ages of 8-10 years to 15-17 years. INTERPRETATION: Using modern causal inference approaches strengthened the evidence of MVPA and sedentary behaviours as key drivers of development of type 2 diabetes in at-risk children and adolescents, and should be considered as key targets for prevention. FUNDING: Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, and Fonds de Recherche du Québec-Santé. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Social Isolation, Loneliness and Health: A Descriptive Study of the Experiences of Migrant Mothers With Young Children (0-5 Years Old) at La Maison Bleue.

Background: Migrant women with young children, including asylum seekers and refugees, have multiple vulnerability factors that put them at increased risk of social isolation and loneliness, which are associated with negative health outcomes. This study explored the experiences of social isolation and loneliness among migrant mothers with children aged 0-5 years as well as their perceptions on possible health impacts. Methods: A qualitative descriptive study was conducted at La Maison Bleue, a non-profit organization providing perinatal health and social services to vulnerable women in Montreal, Canada. Recruitment and data collection occurred concurrently during the COVID-19 pandemic, between November and December 2020. Eleven women participated in individual semi-structured interviews and provided socio-demographic information. Interview data were thematically analyzed. Results: Migrant women in this study described social isolation as the loss of family support and of their familiar social/cultural networks, and loneliness as the feelings of aloneness that stemmed from being a mother in a new country with limited support. Multiple factors contributed to women's and children's social isolation and loneliness, including migration status, socioeconomic circumstances, language barriers, and being a single mother. Women expressed that the COVID-19 pandemic exacerbated pre-existing experiences of social isolation and loneliness. Mothers' experiences affected their emotional and mental health, while for children, it reduced their social opportunities outside the home, especially if not attending childcare. However, the extent to which mothers' experiences of social isolation and loneliness influenced the health and development of their children, was less clear. Conclusion: Migrant mothers' experiences of social isolation and loneliness are intricately linked to their status as migrants and mothers. Going forward, it is critical to better document pandemic and post-pandemic consequences of social isolation and loneliness on young children of migrant families. Supportive interventions for migrant mothers and their young children should not only target social isolation but should also consider mothers' feelings of loneliness and foster social connectedness and belongingness. To address social isolation and loneliness, interventions at the individual, community and policy levels are needed.

Validation of desk-based audits using Google Street View® to monitor the obesogenic potential of neighbourhoods in a pediatric sample: a pilot study in the QUALITY cohort.

BACKGROUND: The suitability of geospatial services for auditing neighbourhood features relevant to pediatric obesity remains largely unexplored. Our objectives were to (i) establish the measurement properties of a desk-based audit instrument that uses Google Street View ® to assess street- and neighbourhood-level features relevant to pediatric obesity (QUALITY-NHOOD tool, the test method) and (ii) comment on its capacity to detect changes in the built environment over an 8-year period. In order to do so, we compared this tool with an on-site auditing instrument (the reference method). METHODS: On-site audits of 55 street- and neighbourhood-level features were completed in 2008 in 512 neighbourhoods from the QUALITY cohort study. In 2015, both repeat on-site and desk-based audits were completed in a random sample of 30 of these neighbourhoods. RESULTS: Agreement between both methods was excellent for almost all street segment items (range 91.9-99.7%), except for road type (81.0%), ads/commercial billboards (81.7%), road-sidewalk buffer zone (76.1%), and road-bicycle path buffer zone (53.3%). It was fair to poor for perceived quality, safety and aesthetics items (range 59.9-87.6%), as well as for general impression items (range 40.0-86.7%). The desk-based method over-detected commercial billboards and road-sidewalk buffer zone, and generally rated neighbourhoods as less safe, requiring more effort to get around, and having less aesthetic appeal. Change detected over the 8-year period was generally similar for both methods, except that the desk-based method appeared to amplify the increase in the number of segments with signs of social disorder. CONCLUSIONS: The QUALITY-NHOOD tool is deemed adequate for evaluating and monitoring changes in pedestrian- and traffic-related features applicable to pediatric populations. Applications for monitoring the obesogenic nature of neighbourhoods appear warranted.

Natural history and determinants of dysglycemia in Canadian children with parental obesity from ages 8-10 to 15-17 years: The QUALITY cohort.

In children, the mechanisms implicated in deterioration of glucose homeostasis versus reversion to normal glucose tolerance (NGT) remain uncertain. We aimed to describe the natural history of dysglycemia from childhood to late adolescence and to identify its early determinants. We used baseline (8-10 years, n = 630), 1st follow-up (10-12 years, n = 564) and 2nd follow-up (15-17 years, n = 377) data from the QUALITY cohort of White Canadian children with parental obesity. Children underwent a 2-h oral glucose tolerance test at each cycle with plasma glucose and insulin measured at 0/30/60/90/120 min. American Diabetes Association criteria defined dysglycemia (impaired fasting glucose, impaired glucose tolerance or type 2 diabetes). Longitudinal patterns of insulin sensitivity and beta-cell function were estimated using generalized additive mixed models. Model averaging identified biological, sociodemographic and lifestyle-related determinants of dysglycemia. Of the children NGT at baseline, 66 (21%) developed dysglycemia without reverting to NGT. Among children with dysglycemia at baseline, 24 (73%) reverted to NGT. In children with dysglycemia at 1st follow-up, 18 (53%) later reverted to NGT. Among biological, sociodemographic and lifestyle determinants at 8-10 years, only fasting and 2-h glucose were associated with developing dysglycemia (odds ratio [95% CI] per 1 mmol/L increase: 4.50 [1.06; 19.02] and 1.74 [1.11; 2.73], respectively). Beta-cell function decreased by 40% in children with overweight or obesity. In conclusion, up to 75% of children with dysglycemia reverted to NGT during puberty. Children with higher fasting and 2-h glucose were at higher risk for progression to dysglycemia, while no demographic/lifestyle determinants were identified.

Associations between family functioning during early to mid-childhood and weight status in childhood and adolescence: findings from a Quebec birth cohort.

BACKGROUND: Impaired family functioning has been associated with obesity in children and adolescents, but few longitudinal studies exist. We examined whether family functioning from early to mid-childhood is associated with overweight and obesity in later childhood and adolescence. METHODS: We examined data from the Quebec Longitudinal Study of Child Development (QLSCD), a birth cohort (N = 2120), collected between 1998 and 2011. Parent-reported family functioning was assessed at 4 time points between ages 0.5 and 8 years using the McMaster Family Assessment Device with established cut-offs for impaired family functioning. Participants were classified as having experienced: 1) early-childhood impaired functioning, 2) mid-childhood impaired functioning, 3) both early and mid-childhood impaired functioning, or 4) always healthy family functioning. Overweight and obesity were determined at 10- and 13-years using WHO criteria. Covariate adjusted multinomial logistic regressions were fitted to the data to examine associations between longitudinal family functioning groups (using the always healthy functioning as reference category) and the likelihood of having overweight and obesity (vs normal weight) at ages 10 (n = 1251) and 13 years (n = 1226). RESULTS: In the 10- and 13-year sub-samples, respectively 10.2% and 12.5% of participants had experienced both early and mid-childhood impaired family functioning. Participants in this group had an increased likelihood of having obesity (vs normal weight) at age 10 years [OR = 2.63 (95% CI: 1.36; 5.08)] and at age 13 years [OR = 1.94 (95% CI: 0.99; 3.80] compared to those in the always healthy functioning group. No associations were found for other family functioning categories or for overweight status. CONCLUSION: Approximately one in ten children experienced impaired family functioning throughout early and mid-childhood. Findings suggest a link between impaired functioning across childhood and the development of obesity at 10 years of age and possibly at 13 years of age.

Neighborhood built environment typologies and adiposity in children and adolescents.

BACKGROUND/OBJECTIVES: Neighborhoods are complex, multidimensional systems. However, the interrelation between multiple neighborhood dimensions is seldom considered in relation to youth adiposity. We created a neighborhood typology using a range of built environment features and examined its association with adiposity in youth. SUBJECTS/METHODS: Analyses are based on data from the QUALITY cohort, an ongoing study on the natural history of obesity in Quebec youth with a history of parental obesity. Adiposity was measured at baseline (8-10 years) and follow up, ~8 years later. Neighborhood features were measured at baseline through in-person neighborhood assessments and geocoded administrative data and were summarized using principal components analysis. Neighborhood types were identified using cluster analysis. Associations between neighborhood types and adiposity were examined using multivariable linear regressions. RESULTS: Five distinct neighborhood types characterized by levels of walkability and traffic-related safety were identified. At ages 8-10 years, children in moderate walkability/low safety neighborhoods had higher BMI Z-scores [ß: 0.41 (0.12; 0.71), p = 0.007], fat mass index [ß: 1.22 (0.29; 2.16), p = 0.010], waist circumference [ß: 4.92 (1.63; 8.21), p = 0.003], and central fat mass percentage [ß: 1.60 (0.04; 3.16), p = 0.045] than those residing in moderate walkability/high safety neighborhoods. Attenuated associations were observed between neighborhood types and adiposity 8 years later. Specifically, residents of moderate walkability/low safety neighborhoods had a higher FMI [ß: 1.42 (-0.07; 2.90), p = 0.062], and waist circumference [ß: 5.04 (-0.26; 10.34), p = 0.062]. CONCLUSIONS: Neighborhoods characterized by lower traffic safety appear to be the most obesogenic to children, regardless of other walkability-related features. Policies targeting neighborhood walkability for children may need to prioritize vehicular traffic safety.

CARDEA study protocol: investigating early markers of cardiovascular disease and their association with lifestyle habits, inflammation and oxidative stress in adolescence using a cross-sectional comparison of adolescents with type 1 diabetes and healthy controls.

INTRODUCTION: Little is known regarding associations between potentially modifiable lifestyle habits and early markers of cardiovascular disease (CVD) in pediatric type 1 diabetes (T1D), hindering early prevention efforts. Specific objectives are: (1) compare established risk factors (dyslipidemia, hypertension) with novel early markers for CVD (cardiac phenotype, aortic distensibility, endothelial function) in adolescents with T1D and healthy age-matched and sex-matched controls; (2) examine associations between these novel early markers with: (i) lifestyle habits; (ii) adipokines and measures of inflammation; and (iii) markers of oxidative stress among adolescents with T1D and controls, and determine group differences in these associations; (3) explore, across both groups, associations between CVD markers and residential neighbourhood features. METHODS AND ANALYSES: Using a cross-sectional design, we will compare 100 participants aged 14-18 years with T1D to 100 healthy controls. Measures include: anthropometrics; stage of sexual maturity (Tanner stages); physical activity (7-day accelerometry); sleep and sedentary behaviour (self-report and accelerometry); fitness (peak oxygen consumption); and dietary intake (three non-consecutive 24- hour dietary recalls). Repeated measures of blood pressure will be obtained. Lipid profiles will be determined after a 12- hour fast. Cardiac structure/function: non-contrast cardiac magnetic resonance imaging (CMR) images will evaluate volume, mass, systolic and diastolic function and myocardial fibrosis. Aortic distensibility will be determined by pulse wave velocity with elasticity and resistance studies at the central aorta. Endothelial function will be determined by flow-mediated dilation. Inflammatory markers include plasma leptin, adiponectin, tumour necrosis factor alpha (TNF-α), type I and type II TNF-α soluble receptors and interleukin-6 concentrations. Measures of endogenous antioxidants include manganese superoxide dismutase, glutathione peroxidase and glutathione in blood. Neighbourhood features include built and social environment indicators and air quality. ETHICS AND DISSEMINATION: This study was approved by the Sainte-Justine Hospital Research Ethics Board. Written informed assent and consent will be obtained from participants and their parents. TRIAL REGISTRATION NUMBER: NCT04304729.

Personal Social Networks and Adiposity in Adolescents: A Feasibility Study.

Background and Objective: Weight-related behaviors are determined by multiple individual and contextual factors, with recent evidence implicating personal social networks (PSNs). Greater understanding of these relationships could help inform healthy weight promoting interventions. We conducted a feasibility study among youth at risk of obesity to document process outcomes, to discern relationships between PSN features and weight-related behaviors, and to generate hypotheses with respect to perceived social support (SS) and sex. Methods: Participants (egos) nominated up to 10 people (alters) with whom they discussed important matters. Egos reported their own and each alter's age, sex, body shape, lifestyle behaviors, relation, frequency of exercising with each alter, and of being encouraged by each alter to exercise. We examined relationships between PSN features and weight-related outcomes and explored the role of SS, using both correlational and linear regression analyses. Results: There were 45 participants (mean age 16.4 years) and body mass index z-score (zBMI) ranged from -1.2 to 3.9. There were few missing responses to PSN items; broad variation across most items, including SS scores, was reported. Correlations pointed to plausible relationships implicating PSN features and lifestyle behaviors. In exploratory analyses, network-based SS was positively associated with adiposity in girls and negatively associated in boys, while lifestyle role modelling was not associated with adiposity. Conclusions: Our findings support the feasibility of measuring the PSN in youth and the potential for using social network analysis to investigate social and behavioral mechanisms associated with obesity.

Body Mass Index Z Score vs Weight-for-Length Z Score in Infancy and Cardiometabolic Outcomes at Age 8-10 Years.

OBJECTIVES: To confirm that World Health Organization weight-for-length z scores (zWFL) and World Health Organization body mass index z scores (zBMI) in infancy are associated with adiposity and cardiometabolic measures at 8-10 years old and to compare the predictive ability of the 2 methods. STUDY DESIGN: zWFL and zBMI at 6, 12, and 18 months of age were computed using data extracted from health booklets, among participants in the Québec Adipose and Lifestyle InvesTigation in Youth prospective cohort (n = 464). Outcome measures at 8-10 years included adiposity, lipid profile, blood pressure, and insulin dynamics. The relationships between zWFL, zBMI, and each outcome were estimated using multivariable linear regression models. Outcome prediction at 8-10 years was compared between the 2 methods using eta-squared and the Lin concordance correlation coefficient. RESULTS: zWFL and zBMI were associated with all measures of adiposity at 8-10 years. Associations with other cardiometabolic measures were less consistent. For both zWFL and zBMI across infancy, eta-squared were highly similar and the Lin coefficients were markedly high (≥0.991) for all outcomes. CONCLUSIONS: There was no evidence that zBMI and zWFL in infancy differed in their ability to predict adiposity and cardiometabolic measures in childhood. This lends support to the sole use of zBMI for growth monitoring and screening of overweight and obesity from birth to 18 years. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03356262.

Determinants of attrition in a pediatric healthy lifestyle intervention: The CIRCUIT program experience.

INTRODUCTION: Attrition in pediatric weight management programs is notoriously high. Greater understanding of its determinants is needed to inform retention strategies. We identified determinants of attrition in CIRCUIT, a healthy lifestyle intervention program for youth at risk of cardiovascular disease. METHODS: A one-arm intervention study of children aged 4-18 years who initiated the CIRCUIT program in the first five years of its existence (N = 403). We defined attrition as attending the baseline visit but ceasing attendance prior to the 1-year follow-up. Potential determinants of dropout included the child's age, sex, ethnicity, body mass index (BMI) z-score, family socio-demographic characteristics, and estimated driving time to the program, all measured at baseline. Associations were estimated bivariately, using chi-squared- and t-tests, and simultaneously in a multivariable logistic regression model. RESULTS: Of the 403 participants who started the program, 198 (49%) dropped out within 12 months of enrollment. Youth who dropped out were older (mean age 12.8y vs. 11.3y; p < 0.01), were less likely to live with both parents (62% vs. 71%; p = 0.05), and to have mothers who had completed high school (79% vs. 88%; p = 0.01). No group differences were observed for sex, ethnicity, baseline BMI z-score, fathers' education, or driving time to the program. In multivariate models, only older age at initiation of the intervention (OR: 1.2; CI: 1.1,1.3) and lower maternal education (OR: 2.0; CI: 1.0,3.8) were associated with dropout. CONCLUSION: Improved tailoring of interventions to older pediatric participants and to families of lower maternal education may help reduce attrition in CIRCUIT and similar lifestyle intervention programs.

Self-reported weight loss attempts and weight-related stress in childhood: Heightening the risk of obesity in early adolescence.

OBJECTIVE: Weight loss attempts occur as early as childhood. The impacts of weight loss attempts and weight-related stress on the occurrence of obesity during childhood remain unknown. We aimed to: (a) assess the prevalence of self-reported weight loss attempts and weight-related stress in 8-10 year-old children and (b) determine associations with adiposity 2 years later. METHOD: Data were collected from a cohort study of 564 Canadian children aged 8-10 years, having one or both biological parents with obesity (Quebec Adipose and Lifestyle Investigation in Youth cohort). Self-reported weight loss attempts and weight-related stress were assessed at baseline in the child's questionnaire. Adiposity was measured at baseline and 2 years later using body mass index z-scores (zBMI), waist-to-height ratio (WHtR), and percentage of body fat (%BF) obtained from dual-energy x-ray absorptiometry. Linear and logistic regression analyses were used while adjusting for potential confounders. RESULTS: Forty-eight percent of children reported previous weight loss attempts and 20% reported weight-related stress. Self-reported weight loss attempts and weight-related stress were associated with higher zBMI, WHtR, and %BF 2 years later in adjusted models, although estimates were attenuated when including baseline adiposity measures. Self-reported weight loss attempts, but not weight-related stress, increased the risk of becoming overweight among children who were normal weight at baseline. DISCUSSION: Weight loss attempts are prevalent in children with parental obesity. Children reporting weight loss attempts and weight-related stress tend to have higher adiposity 2 years later and are more likely to become overweight.

Identifying risk profiles for excess sedentary behaviour in youth using individual, family and neighbourhood characteristics.

There are few known determinants of sedentary behaviour (SB) in children. We generated and compared profiles associated with risk of excess SB among children (n = 294) both at 8-10 and 10-12 years of age (Visits 1 and 2, respectively), using data from the QUebec Adipose and Lifestyle InvesTigation in Youth. Excess SB was measured by accelerometry and defined as >50% of total wear time at <100 counts/minutes. Recursive partitioning analyses were performed with candidate individual-, family-, and neighbourhood-level factors assessed at Visit 1, and distinct groups at varying risk of excess SB were identified for both timepoints. From the ages of 8-10 to 10-12 years, the prevalence of excess SB more than doubled (24.5% to 57.1%). At Visit 1, excess SB was greatest (73%) among children simultaneously not meeting physical activity guidelines, reporting >2 h/day of weekday non-academic screen time, living in low-dwelling density neighbourhoods, having poor park access, and living in neighbourhoods with greater disadvantage. At Visit 2, the high-risk group (70%) was described by children simultaneously not meeting physical activity guidelines, reporting >2 h/day of non-academic screen time on weekends, and living in neighbourhoods with low disadvantage. Risk factors related to individual lifestyle behaviours are generally consistent, and neighbourhood factors generally inconsistent, as children age from late childhood to pre-adolescence. Multiple factors from developmental, behavioural and contextual domains increase risk for excess sedentary behaviour; these warrant consideration to devise effective prevention or management strategies.

Promoting healthy lifestyle behaviours in youth: Findings from a novel intervention for children at risk of cardiovascular disease.

OBJECTIVES: Obesity is the most prevalent risk factor for cardiovascular disease (CVD) in children. We developed a 2-year lifestyle intervention for youth at risk of CVD. We assessed changes in body mass index z-scores (zBMI) and key cardiometabolic risk factors, physical fitness, and capacity among those who completed the program. METHODS: The CIRCUIT program is a multidisciplinary lifestyle intervention for children aged 4 to 18 years at risk of CVD, based on a personalized plan to improve cardiometabolic outcomes by increasing physical activity and reducing sedentary behaviours. Both at baseline and 2-year follow-up, we measured zBMI, blood pressure z-scores (zBP), adiposity (%body and %trunk fat), fasting blood glucose and lipid profile, aerobic (VO2max) and anaerobic (5×5 m shuttle run test) fitness, and physical capacity indicators. Differences between baseline and follow-up were examined using paired t-tests (for age-sex standardized outcomes) and multivariable mixed effect models, adjusted for age and sex (for other outcomes). RESULTS: Among the 106 participants (53 males) who completed the 2-year program, mean age at baseline was 10.9 years (SD=3.2). After 2 years, zBMI and diastolic zBP decreased by 0.30SD (95% CI: -0.44; -0.16) and 0.43SD (95% CI: -0.65; -0.23), respectively. Participants improved %body and %trunk fat, lipid profile, aerobic and anaerobic fitness levels, and physical capacity (p<0.02). No changes in systolic zBP nor in fasting plasma glucose were observed. CONCLUSION: Our findings showed improved zBMI, cardiometabolic outcomes, physical fitness, and capacity among children at risk of CVD, suggesting that CIRCUIT is a promising intervention.