J. Salmon

The association between television viewing and overweight among Australian adults participating in varying levels of leisure-time physical activity.

OBJECTIVES: To investigate the effect of physical activity on the association between television viewing and overweight (body mass index (BMI) ≥25u2005kg/m2).DESIGN: Cross-sectional study administered by interview to adults randomly selected from the electronic white pages.SUBJECTS: 3392 adults (64% response rate) from a representative population sample in the State of New South Wales, Australia.MEASUREMENTS: Self-reported height and weight, two-week leisure-time physical activity recall, one-week average television viewing recall.RESULTS: BMI and physical activity patterns were both associated with hours of television watched. Compared to those participants who reported watching less than one hour of television per day, those watching 1 to 2.5 hours were 93% more likely to be overweight (BMI≥25u2005kg/m2), those watching 2.5 to 4 hours were 183% more likely to be overweight, those watching more than 4 hours per day were four times more likely to be overweight. Physical activity was not directly associated with being overweight, but an interaction between activity and television watching was present. Respondents in the low, moderate and high physical activity categories who reported watching more than 4 hours of television per day were twice as likely to be overweight compared to those who watched less than one hour of television per day, irrespective of physical activity participation.CONCLUSIONS: With approximately half the Australian adult population overweight or obese, these findings indicate that public health strategies to reduce overweight and prevent weight gain may need to focus on reducing sedentary behaviours such as television viewing in addition to increasing physical activity.

Does Preschool Physical Activity and Electronic Media Use Predict Later Social and Emotional Skills at 6 to 8 Years? A Cohort Study

BACKGROUNDnLittle is known about the associations of preschoolers health behaviors with their later psychosocial wellbeing. This study investigates the association of 3- to 5-year-old childrens physical activity and electronic media use with their later social-emotional skills (6-8 years).nnnMETHODSnData were collected in 2008-2009 and 2011-2012 for the Healthy Active Preschool and Primary Years (HAPPY) Study in metropolitan Melbourne. Participants were a random subsample (n = 108) of the 567 children at follow-up. Physical activity was objectively measured using ActiGraph GT1M accelerometers; electronic media use (television viewing, sedentary electronic games and active electronic games) was parent proxy-reported. Social and emotional skills were child-reported using the Bar-On Emotional Quotient Inventory-Youth Version. Regression analyses controlled for sex, clustering by center of recruitment, and accelerometer wear time (for physical activity analyses).nnnRESULTSnSedentary electronic games were positively associated with intrapersonal and stress management skills and total emotional quotient. Computer/internet use was inversely associated with interpersonal, and positively associated with stress management, skills.nnnCONCLUSIONSnFindings suggest that physical activity is not associated with childrens psychosocial health while some types of electronic media use are. Future research should investigate the contexts in which preschoolers participate in these behaviors and potential causal mechanisms of associations.

Interventions to increase physical activity in children 0-5 years old: a systematic review, meta-analysis and realist synthesis: Interventions to increase physical activity

The objective of the study is to evaluate the effectiveness of interventions to increase physical activity (PA) in 0–5 year olds and to determine what works, for whom, in what circumstances.

Seasonal changes in physical activity during school recess and lunchtime among Australian children

ABSTRACT This study examined how children’s physical activity levels during recess and lunchtime and the contribution of recess and lunchtime to daily physical activity differed across seasons. Three hundred and twenty-six children aged 8–11 years from Australia participated. Physical activity was measured every 15-seconds using hip-mounted ActiGraph accelerometers for 7 consecutive days during the winter (n = 246), spring (n = 211), summer (n = 161) and autumn terms (n = 139). Data were collected 2012–2013. Time spent in light- (LPA) moderate- (MPA), vigorous- (VPA), and moderate- to vigorous-intensity physical activity (MVPA) during recess and lunchtime were calculated. Longitudinal data were analysed using multilevel analyses and adjusted for potential confounders. The results showed that compared to winter, children engaged in significantly less MVPA and VPA in spring and summer during lunchtime (p < 0.05). No significant changes were observed during recess. The contribution of lunchtime to VPA and MVPA significantly decreased in spring and summer compared to winter (p < 0.05). Children’s lunchtime physical activity levels decreased between winter and spring and summer, with greater declines observed in VPA. Strategies to increase physical activity levels in every season are needed during lunchtime, with a greater emphasis on warmer months.

O1-5.1 Cluster-randomised controlled trial of an early childhood obesity prevention program: the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) program

Introduction This study aimed to assess the effectiveness of a child-focused early obesity prevention intervention for first-time parents in existing social networks. Methods The Melbourne InFANT Program is a cluster-randomised controlled trial involving 542 families from 62 first-time parent groups in Melbourne, Australia (87% recruitment; 90% retention). It focuses on positive diet, physical activity and reduced sedentary behaviours from 3 to 18u2005months of age. Results At intervention conclusion, childrens objectively measured physical activity was similar across groups. Maternal beliefs about television and diet and corresponding child behaviours were more favourable in intervention than control participants. For example, fewer intervention group mothers believed television is helpful for development (67% vs 43%), and parents should offer other foods if their child doesnt eat their meal (44% vs 20%; both p<0.001). More intervention mothers believed parents should include fruit or vegetables in all childrens meals and snacks (96% vs 91%, p=0.04), and that television should be turned off when children are eating (90% vs 81%, p=0.02). Compared to control group infants, those in the intervention group were significantly more likely to consume two or more serves of fruit (81% vs 70%, p=0.03), vegetables (56% vs 42%, p=0.04) and both fruit and vegetables daily (39% vs 26%, p<0.001) and watched an average of 92u2005min less television per week (β=−13.8, 95% CI −26.4 to −1.2). Conclusions The Melbourne InFANT Program, a low-dose, low-cost obesity prevention intervention, shows promising impact on parent attitudes and beliefs and on childrens diet and television viewing behaviours but not physical activity.

Insufficient physical activity or prolonged sedentary behaviour: Which is the stronger predictor of Body Mass Index?

Studies have shown that insufficient physical activity and prolonged sedentary behaviour are a major risk factor of overweight and obesity. But it is not known which one is more strongly associated with Body Mass Index (BMI). This study examined the role of insufficient physical activity (PA) and prolonged sedentary behaviour (SB) on BMI. A cross-sectional study using a mail survey was conducted to collect the following data from adults living in Adelaide (n=2,104): height, weight, leisure-time physical activity, leisure-time sedentary behaviours (television watching; computer use; video game; reading; sitting and talking; talking on the telephone; and driving) and sociodemographic variables. Participants were categorised into four groups according to the level of PA (High: >= 2.5 hr/wk, Low: = 4 hr/day, Low: < 4 hr/day). Logistic regression analysis found that, compared to participants with High PA/Low SB, the odds ratio of being overweight or obese for those with High PA/High SB was 1.58 (95%CI = 1.22-2.07 p<.001), and that for those with Low PA/Low SB was 1.49 (95%CI = 1.17-1.89, p<.01), and that for those with Low PA/High SB was 2.26 (95%CI = 1.75-2.92, p<.001), controlling for the socio-demographic variables. Comparison of the relevant odds ratios suggests that prolonged sedentary behaviour contributes to a larger BMI as much as insufficient physical activity. Public health policy may need to stress the significance of decreasing sedentary behaviour time, as well as increasing physical activity, to reduce the risk of being overweight or obese.