2 and non-Aboriginal children: a cross-sectional comparison of adiposity and weight 3 related behaviours between 2010 and 2015. 4 5 Abstract 21Background In New South Wales (Australia) there has been substantial long term 22 investment in school-based child obesity prevention programs. Whether these 23 programs have led to population level improvements in children's adiposity and 24 weight-related behaviours in Aboriginal children, who are at greater risk of poorer 25 health outcomes, is yet to be determined. The purpose of this study was to describe 26 changes in adiposity and weight-related behaviours of Aboriginal and non-Aboriginal 27 children and to examine the equality of changes between the two groups. 28 Methods Representative cross-sectional population surveys conducted in 2010 and 29 2015 among children age 5-16 years (n=15,613), stratified by Aboriginality. 30 Indicators of weight-related behaviour (diet, physical activity, school travel, screen-31 time) were measured by questionnaire with parents responding for children age <10 32 years and self-report by children age >10 years. Objective measurements included 33 height, weight, waist circumference, cardiorespiratory fitness, and fundamental 34 movement skills. 35 Results Adiposity prevalences were significantly higher in 2015, than 2010 among 36 non-Aboriginal children only, however adiposity prevalences were consistently higher 37 among Aboriginal than non-Aboriginal children. There were positive changes 38 towards adopting healthier weight-related behaviours in all children between 39 surveys, which were consistently significant among non-Aboriginal, but not 40 Aboriginal, children. The magnitude of changes and the 2015 prevalences in weight-41 related behaviours were generally similar for Aboriginal and non-Aboriginal children, 42 however positive changes in fruit consumption and locomotor skills were significantly 43 larger among Aboriginal than non-Aboriginal children. The prevalence of being 44 driven to school in 2015 was significantly higher than 2010 for both groups.3 45 Conclusions Overall, there are signs that Aboriginal and non-Aboriginal children 46 are shifting towards healthier weight-related behaviours. However, many unhealthy 47 weight-related behaviours remain highly prevalent. Our findings may have utility for 48 the direction of future health policy and service delivery to Aboriginal and non-49 Aboriginal children and the development of health promotion programs to build on 50 these improvements in health behaviours. 51 52 53 Since 2002 there has been substantial investment in New South Wales (NSW) 54 Australia to reduce child obesity through a succession of state plans, policies, and 55 programs to support the healthy development of children from 0-18 years.[1-3] The 56 NSW government strategy was to encourage and support opportunities for the 57 community to be healthy through the delivery of evidence-based, interactive, and 58 relevant programs. Within the education sector, child obesity prevention has been 59 addressed through...