Mediators of longitudinal associations between television viewing and eating behaviours in adolescents

Background: Television viewing has been associated with poor eating behaviours in adolescents. Changing unhealthy eating behaviours is most likely to be achieved by identifying and targeting factors shown to mediate the association between these behaviours. However, little is known about the mediators of the associations between television viewing and eating behaviours. The aim of this study was to examine mediators of the longitudinal associations between television viewing (TV) and eating behaviours among Australian adolescents.Method: Eating behaviours were assessed using a web-based survey completed by a community-based sample of 1729 adolescents from years 7 and 9 of secondary schools in Victoria, Australia, at baseline (2004-2005) and two years later. TV viewing and the potential mediators (snacking while watching TV and perceived value of TV viewing) were assessed via the web-based survey at baseline.Results: Adolescents who watched more than two hours of TV/day had higher intakes of energy-dense snacks and beverages, and lower intakes of fruit two years later. Furthermore, the associations between TV viewing and consumption of energy-dense snacks, energy-dense drinks and fruit were mediated by snacking while watching TV. Perceived value of TV viewing mediated the association between TV viewing and consumption of energy-dense snacks, beverages and fruit.Conclusion: Snacking while watching TV and perceived value of TV viewing mediated the longitudinal association between TV viewing and eating behaviours among adolescents. The efficacy of methods to reduce TV viewing, change snacking habits while watching TV, and address the values that adolescents place on TV viewing should be examined in an effort to promote healthy eating among adolescents.<br /

Maternal and best friends\u27 influences on meal-skipping behaviours

Skipping meals is particularly common during adolescence and can have a detrimental effect on multiple aspects of adolescent health.&nbsp;Understanding the correlates of meal-skipping behaviours is important for the design of nutrition interventions. The present study examined&nbsp;maternal and best friends&rsquo; influences on adolescent meal-skipping behaviours. Frequency of skipping breakfast, lunch and dinner was&nbsp;assessed using a Web-based survey completed by 3001 adolescent boys and girls from years 7 and 9 of secondary schools in Victoria,&nbsp;Australia. Perceived best friend and maternal meal skipping, modelling of healthy eating (eating healthy food, limiting junk food,&nbsp;eating fruit and vegetables) and weight watching were assessed. Best friend and maternal factors were differentially associated with&nbsp;meal-skipping behaviours. For example, boys and girls who perceived that their best friend often skipped meals were more likely to&nbsp;skip lunch (OR &frac14; 2&middot;01, 95% CI 1&middot;33, 3&middot;04 and OR &frac14; 1&middot;93, 95% CI 1&middot;41, 2&middot;65; P,0&middot;001). Boys and girls who perceived that their mother&nbsp;often skipped meals were more likely to skip breakfast (OR &frac14; 1&middot;48, 95% CI 1&middot;01, 2&middot;15; P,0&middot;05 and OR &frac14; 1&middot;93, 95% CI 1&middot;42, 2&middot;59;&nbsp;P,0&middot;001) and lunch (OR &frac14; 2&middot;05, 95% CI 1&middot;35, 3&middot;12 and OR &frac14; 2&middot;02, 95% CI 1&middot;43, 2&middot;86; P,0&middot;001). Educating adolescents on how to&nbsp;assess and interpret unhealthy eating behaviours that they observe from significant others may be one nutrition promotion strategy to&nbsp;reduce meal-skipping behaviour. The involvement of mothers may be particularly important in such efforts. Encouraging a peer subculture&nbsp;that promotes regular consumption of meals and educates adolescents on the detrimental impact of meal-skipping behaviour on health&nbsp;may also offer a promising nutrition promotion strategy.</span

Adolescent television viewing and unhealthy snack food consumption: the mediating role of home availability of unhealthy snack foods

Objective To examine whether home availability of energy-dense snack foods mediates the association between television (TV) viewing and energy-dense snack consumption among adolescents.Design Cross-sectional.Setting Secondary schools in Victoria, Australia.Subjects Adolescents (n 2984) from Years 7 and 9 of secondary school completed a web-based survey, between September 2004 and July 2005, assessing their energy-dense snack food consumption, school-day and weekend-day TV viewing and home availability of energy-dense snack foods.Results School-day and weekend-day TV viewing were positively associated with energy-dense snack consumption among adolescent boys (&beta; = 0&middot;003, P &lt; 0&middot;001) and girls (&beta; = 0&middot;03, P &lt; 0&middot;001). Furthermore, TV viewing (school day and weekend day) were positively associated with home availability of energy-dense snack foods among adolescent boys and girls and home availability of energy-dense snack foods was positively associated with energy-dense snack food consumption among boys (&beta; = 0&middot;26, P &lt; 0&middot;001) and girls (&beta; = 0&middot;28, P &lt; 0&middot;001). Home availability partly mediated the association between TV viewing and energy-dense snack consumption.Conclusions The results of the present study suggest that TV viewing has a significant role to play in adolescent unhealthy eating behaviours. Future research should assess the efficacy of methods to reduce adolescent energy-dense snack food consumption by targeting parents to reduce home availability of energy-dense foods and by reducing TV viewing behaviours of adolescents

IBC CARe Microarray Allelic Population Prevalences in an American Indian Population

Background: The prevalence of variant alleles among single nucleotide polymorphisms (SNPs) is not well known for many minority populations. These population allele frequencies (PAFs) are necessary to guide genetic epidemiology studies and to understand the population specific contribution of these variants to disease risk. Large differences in PAF among certain functional groups of genes could also indicate possible selection pressure or founder effects of interest. The 50K SNP, custom genotyping microarray (CARe) was developed, focusing on about 2,000 candidate genes and pathways with demonstrated pathophysiologic influence on cardiovascular disease (CVD). Methods: The CARe microarray was used to genotype 216 unaffected controls in a study of pre-eclampsia among a Northern Plains, American Indian tribe. The allelic prevalences of 34,240 SNPs suitable for analysis, were determined and compared with corresponding HapMap prevalences for the Caucasian population. Further analysis was conducted to compare the frequency of statistically different prevalences among functionally related SNPs, as determined by the DAVID Bioinformatics Resource. Results: Of the SNPs with PAFs in both datasets, 9.8%,37.2% and 47.1% showed allele frequencies among the American Indian population greater than, less than and either greater or less than (respectively) the HapMap Caucasian population. The 2,547 genes were divided into 53 functional groups using the highest stringency criteria. While none of these groups reached the Bonferroni corrected p value of 0.00094, there were 7 of these 53 groups with significantly more or less differing PAFs, each with a probability of less than 0.05 and an overall probability of 0.0046. Conclusion: In comparison to the HapMap Caucasian population, there are substantial differences in the prevalence among an American Indian community of SNPs related to CVD. Certain functional groups of genes and related SNPs show possible evidence of selection pressure or founder effects

An RCT to evaluate the utility of a clinical protocol for staff in the management of behavioral and psychological symptoms of dementia in residential aged-care settings

Physical activity (PA) is associated with positive cardio-metabolic health and emerging evidence suggests sedentary behavior (SB) may be detrimental to children's health independent of PA. The primary aim of the Transform-Us! study is to determine whether an 18-month, behavioral and environmental intervention in the school and family settings results in higher levels of PA and lower rates of SB among 8-9 year old children compared with usual practice (post-intervention and 12-months follow-up). The secondary aims are to determine the independent and combined effects of PA and SB on children's cardio-metabolic health risk factors; identify the factors that mediate the success of the intervention; and determine whether the intervention is cost-effective

Two Variants of the C-Reactive Protein Gene Are Associated with Risk of Pre-Eclampsia in an American Indian Population

Background: The etiology of pre-eclampsia (PE) is unknown; but it is accepted that normal pregnancy represents a distinctive challenge to the maternal immune system. C-reactive protein is a prominent component of the innate immune system; and we previously reported an association between PE and the CRP polymorphism, rs1205. Our aim was to explore the effects of additional CRP variants. The IBC (Cardiochip) genotyping microarray focuses on candidate genes and pathways related to the pathophysiology of cardiovascular disease. Methods: This study recruited 140 cases of PE and 270 matched controls, of which 95 cases met criteria as severe PE, from an American Indian community. IBC array genotypes from 10 suitable CRP SNPs were analyzed. A replication sample of 178 cases and 427 controls of European ancestry was also genotyped. Results: A nominally significant difference (p value <0.05) was seen in the distribution of discordant matched pairs for rs3093068; and Bonferroni corrected differences (P<0.005) were seen for rs876538, rs2794521, and rs3091244. Univariate conditional logistic regression odds ratios (OR) were nominally significant for rs3093068 and rs876538 models only. Multivariate logistic models with adjustment for mother's age, nulliparity and BMI attenuated the effect (OR 1.58, P = 0.066, 95% CI 0.97–2.58) for rs876538 and (OR 2.59, P = 0.050, 95% CI 1.00–6.68) for rs3093068. An additive risk score of the above two risk genotypes shows a multivariate adjusted OR of 2.04 (P = 0.013, 95% CI 1.16–3.56). The replication sample also demonstrated significant association between PE and the rs876538 allele (OR = 1.55, P = 0.01, 95% CI 2.16–1.10). We also show putative functionality for the rs876538 and rs3093068 CRP variants. Conclusion: The CRP variants, rs876538 and rs3093068, previously associated with other cardiovascular disease phenotypes, show suggestive association with PE in this American Indian population, further supporting a possible role for CRP in PE