Biopsychosocial correlates of weight status perception in Australian adolescents

This study examined the utility of the biopsychosocial model to predict accuracy of weight status perception among Australian adolescents. The factors included in this framework were: age, gender, and BMI-z (biological factors); satisfaction with body weight and shape (psychological factors); socioeconomic status, peer weight (social factors). Cross-sectional data, including measured height and weight, and self-reported weight status, was obtained from 2954 adolescents (mean age = 14.6, 56% male) who participated in the It's Your Move! study. Accuracy of weight status perception was associated with gender, BMI-z, SES, and weight and shape satisfaction. Gender differences in weight status perception were moderated by satisfaction with weight. In boys, weight satisfaction was associated with perceived healthy weight; in girls, it was associated with perceived healthy weight and underweight. Moderately overweight adolescents are most at risk of underestimating their weight status and could benefit from education about the boundaries of the healthy weight range.

Child weight status: Relationships with mother-child mealtime interactions and child eating behaviours

This doctoral thesis highlighted how mother-child interactions surrounding responsiveness, affect, maternal control and child compliance may be influential to children’s self-regulatory behaviours around food and eating, in turn impacting their weight. Support was found for the potential role of such interactions as risk factors in childhood overweight and obesity.

Childhood overweight and obesity: paternal influences on preschool aged children's eating and weight status

This thesis explored the role of paternal parenting styles, paternal child feeding practices, and father-child interactions in the development of preschool aged children’s eating behaviours and weight. Fathers parenting style and feeding practices were not directly associated with child BMI. However, fathers parenting style was predictive of child eating behaviours over time, and children's eating behaviours were associated with higher BMI, which suggests that there may be an indirect effect of parenting style on child BMI via child eating behaviour.

Perception of weight status in Australian adolescents

 This thesis examined Australian adolescents’ perception of their weight and the association of weight perception with weight related behaviours. Overall, this thesis indicated that many adolescents misperceive their weight status and that this is related to gender specific body ideals. Accurate perception of weight did not promote positive health behaviours.

Three year follow-up of an early childhood intervention: what about physical activity and weight status?

Fundamental movement skills are a correlate of physical activity and weight status. Children who participated in a preschool intervention had greater movement skill proficiency and improved anthropometric measures (waist circumference and BMI z scores) post intervention. Three years later, intervention girls had retained their object control skill advantage. The study purpose was to assess whether at three year follow up a) intervention children were more physically active than controls and b) the intervention effect on anthropometrics was still present.

The effect of gender and age on the association between weight status and health-related quality of life in Australian adolescents

Evidence suggests an inverse relationship between excess weight and health-related quality of life (HRQoL) in children and adolescents, however little is known about whether this association is moderated by variables such as gender and age. This study aimed to investigate these relationships.

The stability of weight status through the early to middle childhood years in Australia: a longitudinal study

OBJECTIVES: To investigate the sociodemographic and behavioural factors associated with incidence, persistence or remission of obesity in a longitudinal sample of Australian children aged 4-10 years. SETTING: Nationally representative Longitudinal Study of Australian Children (LSAC). PARTICIPANTS: The sample for this analysis included all children in the Kinder cohort (aged 4-5 years at wave 1) who participated in all four waves of LSAC (wave 1, 2004, aged 4-5 years; wave 2, 2006, aged 6-7 years; wave 3, 2008, aged 8-9 years and wave 4, 2010, aged 10-11 years). Of the 4983 children who participated in the baseline (wave 1) survey, 4169 (83.7%) children completed all four waves of data collection. PRIMARY AND SECONDARY OUTCOME MEASURES: Movement of children between weight status categories over time and individual-level predictors of weight status change (sociodemographic characteristics, selected dietary and activity behaviours). RESULTS: The study found tracking of weight status across this period of childhood. There was an inverse association observed between socioeconomic position and persistence of overweight/obesity. Sugar-sweetened beverages and fruit and vegetable intake and screen time appeared to be important predictors of stronger tracking. CONCLUSIONS: Overweight and obesity established early in childhood tracks strongly to the middle childhood years in Australia, particularly among children of lower socioeconomic position and children participating in some unhealthy behaviour patterns.

Social development measures associated with problem behaviours and weight status in Australian adolescents

During the adolescent years, substance use, anti-social behaviours and overweight/obesity are amongst the major public health concerns. We investigate if risk and protective factors associated with adolescent problem behaviours and substance use are also associated with weight status in young Australian adolescents. Data comes from the 2006 Healthy Neighbourhoods study, a cross-sectional survey of students attending primary (grade 6, mean age 11) and secondary (grade 8, mean age 12) schools in 30 communities across Australia. Adolescents were classified as not overweight, overweight or obese according to international definitions. Logistic and linear regression analyses, adjusted for age, gender and socio-economic disadvantage quartile, were used to quantify associations between weight status (or BMI z-score) and the cumulative number of problem behaviour risk and protective factors. Prevalence of overweight and obesity was 22.6 % (95 % confidence interval (CI), 21.2–24.0 %) and 7.2 % (CI, 6.3–8.3 %). Average number of risk and protective factors present was 4.0 (CI, 3.7–4.2) and 6.2 (CI, 6.1–6.3). Independently, total number of risk factors present was positively associated with likelihood of overweight and obesity, while number of protective factors present was inversely associated with the likelihood of being above a healthy weight. When both risk and protective factors were included in a regression model, only risk factors were associated with the likelihood of being overweight or obese. Average BMI z-score increased by 0.03 units with each additional risk factor present. Prevention programmes targeting developmental risk and protective factors in adolescents that reduce substance use and problem behaviours may also benefit physical health.

Depressive symptomatology, weight status and obesogenic risk among Australian adolescents: a prospective cohort study

OBJECTIVES: Adolescence is a period of increased risk for mental health problems and development of associated lifestyle risk behaviours. This study examined cross-sectional and longitudinal associations between obesogenic risk factors, weight status, and depressive symptomatology in a cohort of Australian adolescents.

DESIGN: Prospective cohort study.

SETTING: The study used repeated measures data from the Australian Capital Territory (ACT) It's Your Move project, an Australian community-based obesity prevention intervention. Intervention effect was non-significant therefore intervention and comparison groups were combined in this study.

PARTICIPANTS: Total sample was 634 secondary school students (female n=338, male n=296) with mean age 13 years (SD=0.6) at baseline (2012) and 15 years (SD=0.6) at follow-up (2014) recruited from 6 government secondary schools in the ACT.

PRIMARY AND SECONDARY OUTCOMES MEASURES: Primary outcome was depressive symptomatology measured by Short Mood and Feelings Questionnaire. Secondary outcomes were weight status, physical activity, screen time and diet related measures.

RESULTS: Increased physical activity was associated to lower depressive symptomatology among males (OR=0.35, p<0.05). Sweet drink (OR=1.15, p<0.05) and takeaway consumption (OR=1.84, p<0.05) were associated with higher levels of depressive symptomatology among females at follow-up. Males who were classified as overweight or obese at baseline, and remained so over the study period, were at increased risk of depressive symptomatology at follow-up (b=1.63, 95% CI 0.33 to 2.92). Inactivity among males over the 2-year study period was predictive of higher depressive symptomatology scores at follow-up (b=2.55, 95% CI 0.78 to 4.32). For females, those who increased their consumption of takeaway foods during the study period were at increased risk for developing depressive symptomatology (b=1.82, 95% CI -0.05 to 3.71).

CONCLUSIONS: There are multiple, probably complex, relationships between diet, physical activity and outcomes of obesity and mental health as well as between the outcomes themselves. Healthier diets and increased physical activity should be foundations for healthier body weight and mental health.

Time use clusters of New Zealand adolescents are associated with weight status, diet and ethnicity

OBJECTIVE: To describe New Zealand adolescent time use clusters and correlate cluster profiles. METHODS: Data were from the cross-sectional 2008/2009 National Survey of Children and Young People's Physical Activity and Dietary Behaviours, which surveyed a random sample of 10-16 year-old New Zealanders (study subset n=679). Time use data were collected using the Multimedia Activity Recall for Children and Adults, and collapsed into 17 age-adjusted variables for sex-specific cluster analysis. Cluster associations with socio-demographic, anthropometric, physical activity and dietary variables were analysed. RESULTS: Three time use clusters were discovered for both boys and girls. For boys, the Techno-active cluster was characterised by high levels of team sports and TV; the Quiet movers cluster by transport (active and passive) and quiet time; and the Social studious cluster by reading, study activities and social interaction. The boys' clusters were associated with ethnicity. The girls'Social sporty cluster was characterised by sports and social interaction; the Screenie tasker cluster by TV, computer, chores and work; and the Super studious cluster by reading, study and school-based activities. The girls' time use cluster membership was associated with weight status and serves of extra foods. CONCLUSIONS: Distinct sex-specific time use clusters and correlate profiles exist among NZ adolescents. IMPLICATIONS: These findings may assist the development of targeted time use interventions to improve adolescent health and well-being.