Australian National Children's Nutrition Research Articles

Cluster analysis and food group consumption in a national sample of Australian girls

Food preferences develop early in life and track into later life. There is limited information on food consumption and dietary patterns in Australian girls. The present study aimed to: (i) determine the frequency of food groups consumed over 1day; (ii) identify dietary clusters based on food group consumption; and (iii) compare dietary intakes and activity variables between clusters. A cross-sectional analysis of 9-16-year-old girls (n=1114) from the 2007 Australian National Children's Nutrition and Physical Activity Survey was performed. Over the whole day, 30% of all girls consumed carbonated sugar drinks, 46% consumed take-away food, 56% consumed fruit, 70% consumed at least one vegetable, and 19% and 30% consumed white and/or red meat, respectively. K-means cluster analysis derived four clusters. Approximately one-third of girls were identified in a Meat and vegetable cluster; these girls had the highest intakes of red meat and vegetables, and tended to have higher intakes of fruit, whole grain breads, low fat yoghurt, and lower intakes of take-away foods and soft drinks. They also had the highest intakes of protein, fibre and micronutrients; and tended to perform more physical activity, compared to girls in the remaining clusters. Girls identified in the Meat and vegetable cluster, on average, consumed more lean red meat, vegetables, fruits, and low-fat dairy products, and had a higher intakes of many nutrients. The high percentage of girls not identified in this cluster suggests the need to inform them on how to make healthy, nutrient dense food choices, and why they require increased nutrient intakes at this time.

Physical activity and screen time behaviour in metropolitan, regional and rural adolescents: A -sectional study of Australians aged 9–16 years

Objectives While there is consistent evidence that rural adults in Australia are less active than their urban counterparts, studies relating geographical remoteness to activity patterns in Australian adolescents have yielded inconsistent results. The aim of this study was to describe objectively and subjectively measured patterns of physical activity and sedentary behaviours across remoteness categories in a representative sample of 9–16 year old Australians. Design: Cross-sectional observational study. Methods: 2071 Australian adolescents provided self-report use of time data on four days and wore a pedometer for at least 6 days within the 2007 Australian National Children's Nutrition and Physical Activity Survey. Comparisons of activity patterns were made across four objectively-determined remoteness categories (Major City, Inner Regional, Outer Regional and Remote), adjusting for household income, parental education and age. Results: Adolescents living in major cities self-reported 11–29 min less moderate to vigorous physical activity each day than their counterparts living in geographically more remote areas, and took 150–850 fewer steps each day. While there were no differences in time spent in sport or active transport, differences in free play participation were significant. Males in major cities also reported higher levels of screen time. Differences were somewhat more marked among males than among females. Conclusions: Activity levels among Australian adolescents show contrasting patterns of geographical differences to those found in Australian adults. Higher levels of free play among rural Australian adolescents may be due to more available space and less fear of traffic and stranger risks.

Dietary patterns and breast-feeding in Australian children

To determine the dietary patterns of a national sample of 2-8-year-old Australian children and to establish whether breast-feeding is associated with dietary patterns in this age group. Cross-sectional study using 24 h recall data from the 2007 Australian National Children's Nutrition and Physical Activity Survey. Australia. A total of 2287 children aged 2-8 years. Principal component factor analysis identified three distinct patterns. The 'Non-core food groups' pattern included food groups such as whole-fat dairy products, cheese, medium-high sugar-sweetened breakfast cereals and sweet biscuits, no fruit, reduced/low-fat dairy products and wholegrain bread/rolls. The 'Healthy, meat and vegetable' pattern included vegetables, red meat, fruit and wholegrain bread/rolls and was inversely associated with take-away foods and carbonated sugar-sweetened beverages. The 'Combination' pattern contained many food groups including candy (not chocolate based), pasta/rice products, nuts/seeds, cakes and chocolate, but no fruit or vegetables. Of the 2287 children, 2064 (89·3 %) had been breast-fed. A positive association was found between breast-feeding and the healthy, meat and vegetable pattern (r = 0·267) but not with the other two patterns. Higher scores on this pattern were also associated with younger age, lower BMI, higher birth weight, high likelihood of being in the less-disadvantaged Socio-economic Indexes for Areas category and less likelihood of the child's parents having a lower educational level. These results provide suggestive evidence that breast-feeding during infancy is associated with a healthy dietary pattern in childhood and offers a likely pathway to explain the previously reported association between breast-feeding and chronic disease.

Changes in core food intake among Australian children between 1995 and 2007

To assess the changes in the consumption of core foods among Australian children between the 1995 National Nutrition Survey (1995 NNS) and the 2007 Australian National Children's Nutrition and Physical Activity Survey (2007 Children's Survey). Core food consumption was analysed using 24-h recall data from 2-16 year old children using the 1995 NNS (n=2435) and the 2007 Children's Survey (n=4380). Differences in percent consuming, amounts consumed and percent energy contribution were assessed. The consumption of core foods increased significantly between the 1995 and 2007 surveys, including per-capita consumption and percent energy contribution (both P0.001). Core foods contributed to 59% of energy intake in 1995 compared with 65% in 2007. The types of core foods consumed also changed during this time period with more children reporting eating healthy options such as wholemeal bread, reduced-fat milk, reduced-fat cheese and fruit in the 2007 Children's Survey. Conversely, the consumption of white bread, full-fat milk and low-fibre breakfast cereals was lower in 2007. Overall, reported dietary intake had improved from 1995 to 2007 among Australian children with an increase in the amounts of core foods consumed and healthier types of foods being chosen. Continued health-promotion activities and monitoring of food consumption are highly warranted.

Dietary glycaemic index and glycaemic load among Australian children and adolescents

There are no published data regarding the overall dietary glycaemic index (GI) and glycaemic load (GL) of Australian children and adolescents. We therefore aim to describe the dietary GI and GL of participants of the 2007 Australian National Children's Nutrition and Physical Activity Survey (2007ANCNPAS), and to identify the main foods contributing to their GL. Children, aged 2-16 years, who provided two 24 h recalls in the 2007ANCNPAS were included. A final dataset of 4184 participants was analysed. GI of each food item was assigned using a previously published method. GL was calculated, and food groups contributing to the GL were described by age group and sex. The weighted mean dietary GI and GL of the participants were 54 (SD 5) and 136 (SD 44), respectively. Among the nutrients examined, Ca had the highest inverse relationship with GI (P < 0·001), while percentage energy from starch was most positively associated with GI. The association between fibre density and GI was modest, and percentage energy from sugar had an inverse relationship with GI. Daily dietary GL contributed by energy-dense and/or nutrient-poor (EDNP) items in subjects aged 14-16 years was more than doubled that of subjects aged 2-3 years. To conclude, Australian children and adolescents were having a high-GI dietary pattern characterised by high-starchy food intake and low Ca intake. A significant proportion of their dietary GL was from EDNP foods. Efforts to reduce dietary GI and GL in children and adolescents should focus on energy-dense starchy foods.

Changes in ‘extra’ food intake among Australian children between 1995 and 2007

To examine the consumption patterns of energy-dense, nutrient-poor 'extra' foods among Australian children and to determine any changes in consumption since the 1995 National Nutrition Survey (1995 NNS). 'Extra' food consumption was analysed by age group and gender using 24-h recall data from the 2007 Australian National Children's Nutrition and Physical Activity Survey (2007 Survey; n = 4380) and the 1995 NNS (n = 2435). Differences in percent consuming, amounts consumed and percent energy contribution were assessed. 'Extra' foods contributed 35% to daily energy intake in the 2007 survey, ranging from 24% in the 2-3 year olds to 38% in the 9-13 and 14-16 year olds. The foods contributing most to energy intake included 'fried potatoes' (2.9%), 'cakes, muffins, slices' (2.9%) and 'potato crisps and similar snacks' (2.6%). Compared to the 1995 NNS, total energy intake was significantly lower in the 2007 Survey (8621 kJ in 1995 versus 8330 kJ in 2007), as was the consumption of 'extra' foods (both in terms of weight and energy) (3645 kJ in 1995 versus 3049 kJ in 2007). All age groups reported a decline in energy intake from 'extra' foods of approximately 600 kJ. The overall consumption of 'extra' foods seems to have decreased from 1995 to 2007. However, 'extra' foods continue to be over-consumed by Australian children and continuous monitoring of 'extra' foods consumption is highly warranted.

The type and prevalence of activities performed by Australian children during the lunchtime and after school periods

Objectives: The aim of this study was to identify the most prevalent reported activities performed by Australian children during the lunchtime and after school periods; and estimate the mean duration of a typical bout of the most prevalent activities performed during the lunchtime and after school periods. Design: This study was a secondary data analysis of the 2007 Australian National Children's Nutrition and Physical Activity Survey. Method: Use of time data were collected from Australian children aged 10.0–13.9 years ( n = 794) using the Multimedia Activity Recall for Children and Adults (MARCA). The most prevalent self-reported activities for the lunchtime and after school period on school days were determined by mean duration across the sample. The estimated energy cost for each of the activities was reported based on the Compendium of Energy Expenditures for Youth. Results: A list of the 20 most prevalent lunchtime activities and 30 most prevalent after school activities is presented. Of the most prevalent lunchtime activities, 35% were classified as sedentary and 65% as moderate to vigorous physical activities. During the after school period, 57% of the most prevalent activities were classified as sedentary and only 43% as moderate to vigorous physical activities. Conclusions: These data may assist in the development or refinement of activity checklists with greater content validity, which may be used in combination with objective measures to provide important contextual information about the types of activities being performed and inform the development of appropriately targeted interventions.

The influence of secular trend for height on ascertainment and eligibility for growth hormone treatment

Assessment of short stature in many instances is based on a comparison with the Centers for Disease Control's (CDC) growth curves. The secular trend for height may limit the utility of CDC data for contemporary populations. We investigate the effect of the secular trend on Australian and US populations. Describe CDC-defined height SDS distributions of contemporary populations for different ages and genders. Compare observed means and standard deviations (SDs) to expected values of 0 and 1. Compare frequency of individuals shorter than the CDC-1st centile to those shorter than 1st centile defined empirically from the contemporary population. Healthy Kids Queensland Survey 2006: 1686 boys, 1822 girls. Australian National Children's Nutrition and Physical Activity Survey 2007: 2415 boys, 2379 girls. US National Health and Nutrition Examination Survey 2005-2006: 2160 boys, 2118 girls. Means, SDs and normality of CDC-defined height SDS distributions. Frequency of individuals shorter than the CDC-1st centile and shorter than an empirically defined 1st centile. In Australia, means of CDC-defined height SDS distributions are always greater than 0 and the CDC-1st centile identifies only the shortest 0·5% of children. Means may vary with age and occasionally between genders in contemporary populations. Normality and SDs of 1 are retained. The secular trend has resulted in an underestimate of the number of Australian children eligible for GH treatment using the CDC-1st centile cut-off. Contemporary, local data should be used to construct standards. Using the 2nd CDC centile would approximate the 1st local centile until new standards are constructed. The secular trend does not account for the gender bias in GH therapy.