Anthea Magarey

Predicting obesity in early adulthood from childhood and parental obesity

OBJECTIVE: To determine the degree of tracking of adiposity from childhood to early adulthood, and the risk of overweight in early adulthood associated with overweight in childhood and parental weight status in a cohort of children born in the mid-1970s.DESIGN: Longitudinal observational study.SUBJECTS: Approximately 155 healthy boys and girls born in Adelaide, South Australia, 1975–1976 and their parents.MEASUREMENTS: Height and weight of subjects at 2 y, annually from 4 to 8 y, biennially from 11 to 15 y and at 20 y, and of parents when subjects were aged 8 y. Body mass index (BMI) of subjects converted to standard deviation scores and prevalence of overweight and obesity determined using worldwide definitions. Parents classified as overweight if BMI≥25 kg/m2. Tracking estimated as Pearsons correlation coefficient. Risk ratio used to describe the association between weight status at each age and parental weight status and weight status at 20 y and weight status at each earlier age, both unadjusted and adjusted for parental weight status.RESULTS: The prevalence of overweight/obesity increased with age and was higher than that reported in international reference populations. Tracking of BMI was established from 6 y onwards to 20 y at r-values >0.6, suggesting that BMI from 6 y is a good indicator of later BMI. Tracking was stronger for shorter intervals and for those subjects with both parents overweight compared with those with only one or neither parent overweight. Weight status at an earlier age was a more important predictor of weight status at 20 y than parental weight status, and risk of overweight at 20 y increased further with increasing weight status of parents.CONCLUSION: Strategies for prevention of overweight and targeted interventions for prevention of the progression of overweight to obesity are urgently required in school-aged children in order to stem the epidemic of overweight in the adult population.

Twelve-Month Effectiveness of a Parent-led, Family-Focused Weight-Management Program for Prepubertal Children: A Randomized, Controlled Trial

BACKGROUND. Parenting-skills training may be an effective age-appropriate child behavior-modification strategy to assist parents in addressing childhood overweight. OBJECTIVE. Our goal was to evaluate the relative effectiveness of parenting-skills training as a key strategy for the treatment of overweight children. DESIGN. The design consisted of an assessor-blinded, randomized, controlled trial involving 111 (64% female) overweight, prepubertal children 6 to 9 years of age randomly assigned to parenting-skills training plus intensive lifestyle education, parenting-skills training alone, or a 12-month wait-listed control. Height, BMI, and waist-circumference z score and metabolic profile were assessed at baseline, 6 months, and 12 months (intention to treat). RESULTS. After 12 months, the BMI z score was reduced by ∼10% with parenting-skills training plus intensive lifestyle education versus ∼5% with parenting-skills training alone or wait-listing for intervention. Waist-circumference z score fell over 12 months in both intervention groups but not in the control group. There was a significant gender effect, with greater reduction in BMI and waist-circumference z scores in boys compared with girls. CONCLUSION. Parenting-skills training combined with promoting a healthy family lifestyle may be an effective approach to weight management in prepubertal children, particularly boys. Future studies should be powered to allow gender subanalysis.

Comparison of metabolic syndrome prevalence using six different definitions in overweight pre-pubertal children enrolled in a weight management study

Objectives:To assess the implications of variation in Metabolic Syndrome (MS) definition (biochemical and anthropometric indicators) on MS prevalence estimates in a population of overweight and mildly obese children.Design:Cross-sectional study.Subjects:Ninety-nine (64 girls) overweight or mildly obese, but otherwise healthy, pre-pubertal 6–9-year olds recruited for a randomized controlled trial of weight management.Measures:Height, weight and waist circumference were measured with BMI and waist z-scores calculated. Fasting cholesterol and fractions, glucose and insulin were measured, together with systolic and diastolic blood pressure (BP). Anthropometric and metabolic indicators were classified as normal or elevated using adult- or child-specific cut points with clustering of MS indicators also assessed using two adult and three child-specific definitions.Results:A total of 0–4% of subjects were classified with MS when adult definitions were applied. This increased to between 39 and 60% using child-specific definitions, varying according to whether hyperinsulinaemia was central to the MS classification. Systolic BP, triglycerides, total cholesterol, high-density lipoprotein cholesterol and waist z-score increased across insulin quartiles (P<0.05). The use of body mass index and waist circumference in the MS definition classified the same subjects.Conclusions:The classification of MS in children depends strongly on the definition chosen, with MS prevalence estimates higher if insulin is part of the definition and child-specific cut points for metabolic indicators are used. Hyperinsulinaemia and MS are common consequences of childhood obesity but they are not commonly part of the assessment or management plan for weight management in children. There is a need for the establishment of normal insulin ranges and consistent definition of MS in childhood and adolescence.

Assessing dietary intake in children and adolescents: Considerations and recommendations for obesity research

Abstract Dietary intake and food habits are important contributors to the obesity epidemic. They are highly modifiable components of energy balance and are usually targeted in both obesity prevention and treatment programs. However, measurement of total diet creates challenges and can convey a large burden in terms of cost, technical expertise, impact on respondents and time. It is not surprising therefore that comprehensive reports of dietary intake in children are uncommon and, when reported, have limitations. The aim of this paper is to guide researchers and practitioners in selecting the most appropriate dietary assessment method for situations involving children and adolescents. This paper presents a summary of the issues to consider when choosing a method, a description of some of the more commonly used dietary assessment methods for young people and a series of case-studies to illustrate the range of circumstances faced when measuring dietary intake. We recommend that researchers consider the specific components of dietary intake addressed in their research and practice, and whether diet should be reported comprehensively or as targeted components. Other considerations include age, cognitive ability, weight status, physical activity level, respondent burden, and reliability and validity in the context of program goals and research questions. A checklist for selecting the appropriate dietary methodology is provided. This guide aims to facilitate the reporting of dietary intake and food habits in the context of obesity using valid and reliable measures, thus contributing to the evidence-base for nutrition policies and programs relating to obesity.

Reliability and relative validity of a child nutrition questionnaire to simultaneously assess dietary patterns associated with positive energy balance and food behaviours, attitudes, knowledge and environments associated with healthy eating

BackgroundFood behaviours, attitudes, environments and knowledge are relevant to professionals in childhood obesity prevention, as are dietary patterns which promote positive energy balance. There is a lack of valid and reliable tools to measure these parameters. The aim of this study was to determine the reliability and relative validity of a child nutrition questionnaire assessing all of these parameters, used in the evaluation of a community-based childhood obesity prevention project.MethodsThe development of the 14-item questionnaire was informed by the aims of the obesity prevention project. A sub-sample of children aged 10–12 years from primary schools involved in the intervention was recruited at the projects baseline data collection (Test 1). Questionnaires were readministered (Test 2) following which students completed a 7-day food diary designed to reflect the questionnaire. Twelve scores were derived to assess consumption of fruit, vegetables, water, noncore foods and sweetened beverages plus food knowledge, behaviours, attitudes and environments. Reliability was assessed using (a) the intra class correlation coefficient (ICC) and 95% confidence intervals to compare scores from Tests 1 and 2 (test-retest reliability) and (b) Cronbachs alpha (internal consistency). Validity was assessed with Spearman correlations, bias and limits of agreement between scores from Test 1 and the 7-day diaries. The Wilcoxon signed rank test checked for significant differences between mean scores.ResultsOne hundred and forty one students consented to the study. Test 2 (n = 134) occurred between eight and 36 days after Test 1. For 10/12 scores ICCs ranged from 0.47–0.66 (p < 0.001) while for two scores ICCs were < 0.4 (p < 0.05). Spearman correlations ranged from 0.34–0.48 (p < 0.01) and Cronbachs alpha 0.50–0.80. Three scores were modified based on this analysis. The Wilcoxon signed rank test found no evidence of a difference between means (p > 0.05) for 10/12 (test-retest reliability) and 3/7 (validity) scores.ConclusionThis child nutrition questionnaire is a valid and reliable tool to simultaneously assess dietary patterns associated with positive energy balance, and food behaviours, attitudes and environments in Australian school children aged 10–12 years. Thus it can be used to monitor secular changes in these parameters and measure the effectiveness of this and other obesity prevention projects with similar aims.

Placental weight, birth measurements, and blood pressure at age 8 years.

OBJECTIVE: To examine relationships between blood pressure during childhood and both placental weight and body size at birth, in an Australian population. DESIGN: A follow up study of a birth cohort, undertaken when cohort members were aged 8 years. SETTING: Adelaide, South Australia. SUBJECTS: 830 children born in the Queen Victoria Hospital in Adelaide, South Australia, during 1975-6. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressure measured when the children were aged 8 years. RESULTS: Blood pressure at 8 years was positively related to placental weight and inversely related to birth weight, after adjusting for the childs current weight. For diastolic pressure there was a decrease of 1.0 mm Hg for each 1 kg increase in birth weight (95% confidence interval (CI) = -0.4 to 2.4) and an increase of 0.7 mm Hg for each 100 g increase in placental weight (95% CI = 0.1 to 1.3). Diastolic pressure was also inversely related to chest circumference at birth, independently of placental weight, with a decrease of 0.3 mm Hg for each 1 cm increase in chest circumference (95% CI = 0.2 to 0.5). CONCLUSIONS: These findings are further evidence that birth characteristics, indicative of fetal growth patterns, are related to blood pressure in later life.

Contribution of ‘noncore’ foods and beverages to the energy intake and weight status of Australian children

Objectives:The Australian Guide to Healthy Eating is based on five core food groups and water. Foods or beverages that do not fit into these groups are considered extra or ‘noncore’. We tested the hypotheses that noncore foods and beverages make a greater proportional contribution to mean daily energy intakes of: (1) children, compared with other age groups; and (2) overweight and obese children, compared with healthy weight children.Design, setting and subjects:We used data from 13 858 participants aged 2 to 80+ y who had 24-h dietary recall data collected in the 1995 cross-sectional Australian National Nutrition Survey. ANOVA was used to compare the percentage of energy provided by noncore foods and beverages by age and weight status.Results:Children (5 to 12 y) and adolescents (13 to 18 y) obtained significantly more (P<0.001) of their daily food energy from noncore foods (41.5 and 43.4%, respectively) than all other age groups. These age groups also obtained significantly more (P<0.001) of their daily beverage energy from noncore beverages (30.7 and 36.9%, respectively). Results were not consistent with weight status, although very young (2–4 y) obese children obtained significantly more energy (P<0.05) from noncore beverages than children in a healthy weight range. Younger children may also have consumed a greater quantity of foods and beverages. Under-reporting may have obscured similar results for older children.Conclusions:By definition, noncore foods and beverages are surplus to the requirements of a healthy diet. We found that Australian children consume these foods and beverages in excess.

Fruit and vegetable intakes of Australians aged 2–18 years: an evaluation of the 1995 National Nutrition Survey data

Objective: To evaluate the fruit and vegetable intakes of 2 to 18‐year‐old Australians.

Determinants of rapid weight gain during infancy: baseline results from the NOURISH randomised controlled trial

BackgroundRapid weight gain in infancy is an important predictor of obesity in later childhood. Our aim was to determine which modifiable variables are associated with rapid weight gain in early life.MethodsSubjects were healthy infants enrolled in NOURISH, a randomised, controlled trial evaluating an intervention to promote positive early feeding practices. This analysis used the birth and baseline data for NOURISH. Birthweight was collected from hospital records and infants were also weighed at baseline assessment when they were aged 4-7 months and before randomisation. Infant feeding practices and demographic variables were collected from the mother using a self administered questionnaire. Rapid weight gain was defined as an increase in weight-for-age Z-score (using WHO standards) above 0.67 SD from birth to baseline assessment, which is interpreted clinically as crossing centile lines on a growth chart. Variables associated with rapid weight gain were evaluated using a multivariable logistic regression model.ResultsComplete data were available for 612 infants (88% of the total sample recruited) with a mean (SD) age of 4.3 (1.0) months at baseline assessment. After adjusting for mothers age, smoking in pregnancy, BMI, and education and infant birthweight, age, gender and introduction of solid foods, the only two modifiable factors associated with rapid weight gain to attain statistical significance were formula feeding [OR = 1.72 (95%CI 1.01-2.94), P = 0.047] and feeding on schedule [OR = 2.29 (95%CI 1.14-4.61), P = 0.020]. Male gender and lower birthweight were non-modifiable factors associated with rapid weight gain.ConclusionsThis analysis supports the contention that there is an association between formula feeding, feeding to schedule and weight gain in the first months of life. Mechanisms may include the actual content of formula milk (e.g. higher protein intake) or differences in feeding styles, such as feeding to schedule, which increase the risk of overfeeding.Trial RegistrationAustralian Clinical Trials Registry ACTRN12608000056392

A Parent-Led Family-Focused Treatment Program for Overweight Children Aged 5 to 9 Years: The PEACH RCT

OBJECTIVE: To evaluate a healthy lifestyle intervention to reduce adiposity in children aged 5 to 9 years and assess whether adding parenting skills training would enhance this effect. PARTICIPANTS AND METHODS: We conducted a single-blinded randomized controlled trial of prepubertal moderately obese (International Obesity Task Force cut points) children, aged 5 to 9 years. The 6-month program targeted parents as the agents of change for implementing family lifestyle changes. Only parents attended group sessions. We measured BMI and waist z scores and parenting constructs at baseline, 6, 12, 18, 24 months. RESULTS: Participants (n = 169; 56% girls) were randomized to a parenting skills plus healthy lifestyle group (n = 85) or a healthy lifestyle–only group (n = 84). At final 24-month assessment 52 and 54 children remained in the parenting skills plus healthy lifestyle and the healthy lifestyle–only groups respectively. There were reductions (P < .001) in BMI z score (0.26 [95% confidence interval: 0.22–0.30]) and waist z score (0.33 [95% confidence interval: 0.26–0.40]). There was a 10% reduction in z scores from baseline to 6 months that was maintained to 24 months with no additional intervention. Overall, there was no significant group effect. A similar pattern of initial improvement followed by stability was observed for parenting outcomes and no group effect. CONCLUSIONS: Using approaches that specifically target parent behavior, relative weight loss of ∼10% is achievable in moderately obese prepubertal children and can be maintained for 2 years from baseline. These results justify an investment in treatment as an effective secondary obesity-prevention strategy.