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.

Understanding gestational weight gain: the role of weight-related expectations and knowledge

BACKGROUND: Health behaviour theories acknowledge that beliefs, attitudes and knowledge contribute to health behaviours, yet the role of these cognitions in predicting weight gain during pregnancy has not been widely researched. AIMS: To explore and compare the predictive nature of gestational weight gain (GWG) expectations and knowledge on weight gain during pregnancy. MATERIALS AND METHODS: One hundred and sixty-six women were tracked during pregnancy. Participants provided information on prepregnancy weight, height, GWG expectations and knowledge at 16-18 weeks' gestation (Time 1). To calculate gestational weight gain, prepregnancy weight was subtracted from weight at 36 weeks' gestation (collected at Time 2). Gestational weight gain above the Institute of Medicine's GWG recommendations was classified as excessive. A hierarchical regression examined the predictive nature of GWG expectations for actual GWG. Chi-square significance tests determined whether the accuracy of GWG knowledge differed depending on GWG status and prepregnancy BMI category. RESULTS: GWG expectations were a significant predictor of weight gain during pregnancy. Women who experienced excessive GWG were more likely to overestimate the minimum amount of weight that they needed to gain to have a healthy baby. CONCLUSIONS: GWG expectations are predictive of actual GWG, and GWG knowledge among women is generally poor. In particular, overestimating of the minimum amount of weight to gain during pregnancy is associated with excessive GWG. As such, it may be beneficial to design interventions to prevent excessive GWG that targets these cognitions.

Weight perception in overweight adolescents: Associations with body change intentions, diet and physical activity

This study examined the association of weight perception and weight satisfaction with body change intentions and weight-related behaviours in 928 overweight adolescents (aged 11-18 years, 44% female). Accurate perception of weight was associated with trying to lose weight and inaccurate perception was associated with trying to gain muscle. Weight dissatisfaction was associated with trying to lose weight and gain muscle. Accurate weight perception and weight dissatisfaction were not associated with healthy weight-related behaviours. Awareness of overweight and body dissatisfaction may be detrimental to the adoption of healthy weight-control behaviours. Interventions with overweight adolescents should encourage body satisfaction, rather than promoting awareness of overweight.

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.

Changes in the rates of weight and waist circumference gain in Australian adults over time: a longitudinal cohort study

OBJECTIVE: To assess in a single cohort whether annual weight and waist circumference (WC) change has varied over time.

DESIGN: Longitudinal cohort study with three surveys (1) 1999/2000; (2) 2004/2005 and (3) 2011/2012. Generalised linear mixed models with random effects were used to compare annualised weight and WC change between surveys 1 and 2 (period 1) with that between surveys 2 and 3 (period 2). Models were adjusted for age to analyse changes with time rather than age. Models were additionally adjusted for sex, education status, area-level socioeconomic disadvantage, ethnicity, body mass index, diabetes status and smoking status.

SETTING: The Australian Diabetes, Obesity and Lifestyle study (AusDiab)-a population-based, stratified-cluster survey of 11247 adults aged ≥25 years. PARTICIPANTS: 3351 Australian adults who attended each of three surveys and had complete measures of weight, WC and covariates.

PRIMARY OUTCOME MEASURES: Weight and WC were measured at each survey. Change in weight and WC was annualised for comparison between the two periods.

RESULTS: Mean weight and WC increased in both periods (0.34 kg/year, 0.43 cm/year period 1; 0.13 kg/year, 0.46 cm/year period 2). Annualised weight gain in period 2 was 0.11 kg/year (95% CI 0.06 to 0.15) less than period 1. Lesser annual weight gain between the two periods was not seen for those with greatest area-level socioeconomic disadvantage, or in men over the age of 55. In contrast, the annualised WC increase in period 2 was greater than period 1 (0.07 cm/year, 95% CI 0.01 to 0.12). The increase was greatest in men aged 55+ years and those with a greater area-level socioeconomic disadvantage.

CONCLUSIONS: Between 2004/2005 and 2011/2012, Australian adults in a national study continued to gain weight, but more slowly than 1999/2000-2004/2005. While weight gain may be slowing, this was not observed for older men or those in more disadvantaged groups, and the same cannot be said for WC.

Family average income and body mass index above the healthy weight range among urban and rural resicents in regional Mainland China

Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.

Does weight status influence associations between children's fundamental movement skills and physical activity?

This study sought to determine whether weight status influences the association among children's fundamental movement skills (FMS) and physical activity (PA). Two hundred forty-eight children ages 9-12 years participated. Proficiency in three object-control skills and two locomotor skills was examined. Accelerometers objectively assessed physical activity. Body mass index was calculated to determine weight status. Correlations between physical activity and FMS proficiency were evident among boys and girls. No significant interaction was apparent when examining FMS proficiency scores, PA variables, and weight status. Future studies should examine a broader range of skills and types of activities to better characterize this relationship and to inform the promotion of movement skill proficiency and PA.

The effect of physical activity on psychological distress, cortisol and obesity: results of the farming fit intervention program

Background:
Rural and regional Australians have a higher likelihood of mental illness throughout their lifetime than people living in major cities, although the underlying reasons are not yet well defined. Additionally, rural populations experience more lifestyle associated co-morbidities including obesity, diabetes and cardiovascular disease. Research conducted by the National Centre for Farmer Health between 2004 and 2009 revealed a positive correlation between obesity and psychological distress among the farming community. Chronic stress is known to overstimulate the regulation of the hypothalamic-pituitary-adrenal (HPA) axis and cortisol secretion which are associated with abdominal adiposity. Increasing physical activity may normalise cortisol secretion and thereby positively impact both physical and mental health. This paper assesses the effects of increasing physical activity on obesity, health behaviors and mental health in Victorian farming men and women.

Methods:
Farming Fit was a six month quasi-experimental (convenience sample) longitudinal design control-intervention study. Overweight or obese (BMI ?25?kg/m2) farm men (n?=?43) and women (n?=?29) were recruited with demographic, health behaviors, anthropometric, blood pressure and biochemistry data collected at baseline and at a six months. Salivary cortisol and depression anxiety stress scale results were collected at baseline, three and six months. The intervention group (n?=?37) received a personalized exercise program and regular phone coaching to promote physical activity.

Results:
The intervention group showed significant reductions in body weight and waist circumference. Results indicated that following the six month exercise program, the intervention group were 2.64???0.65?kg lighter (p?<?0.001), had reduced waist circumference by 2.01???0.86?cm (p?=?0.02) and BMI by 0.97???0.22?kg/m2 (p?<?0.001) relative to the control group.

Conclusion:
Increasing physical activity altered measures of obesity in farm men and women but did not affect mental health measures or cortisol secretion levels.

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 overweight/obesity on cardiovascular responses to acute psychological stress in men aged 50-70 years.

To determine the effect of adiposity in males aged 50-70 years on cardiovascular responses to acute psychological stress.