International Journal of Behavioral Nutrition and Physical Activity - Latest Articles

Stability and change in potential correlates of physical activity and association with pubertal status among Norwegian children in the transition between childhood and adolescence

Mekdes Gebremariam — 2012-05-11T00:00:00Z

Background: Whereas tracking and change in physical activity (PA) in children and adolescents have been well documented, studies investigating these patterns in its correlates are lacking. The present study aims to address this gap and in addition explore the impact of pubertal status on PA and its potential psychological and social-environmental correlates in a sample of Norwegian children over a 20-month period. Methods: A total of 885 students from 25 control schools of an intervention study, the HEalth In Adolescents (HEIA) study were included (mean age at baseline 11.2 (0.3)). The baseline took place in September 2007, the first follow-up in May 2008 and the second follow-up in May 2009. PA and its potential correlates (enjoyment of PA, self-efficacy related to barriers to PA, perceived support for PA from parents, friends and teachers, perceived social inclusion and perceived environmental opportunities for PA) were self-reported. Pubertal status was assessed using the Pubertal Development Scale. Repeated-measures ANOVA was used to explore changes. Tracking was assessed using Spearman's rank order correlation. Pubertal groups were compared using ANOVA or ANCOVA (controlling for BMI). Multiple regression analyses were used to investigate whether pubertal stage at age 11 would predict levels of correlates and PA at age 13. Results: Potential correlates of PA and the behaviour itself were found to track moderately in the transition between childhood and adolescence. Small but significant changes in enjoyment of PA and teachers' support for PA in both genders and in friends' support for PA and perceived environmental opportunities for PA in females in a direction unfavourable to PA were detected. A few weak positive associations between pubertal stage and correlates of PA at age 11 were noted among boys. Conclusions: Enjoyment of PA, self-efficacy related to barriers to PA, perceived social support for PA, perceived social inclusion, perceived environmental opportunities for PA and the behaviour itself were found to be moderately stable in the transition between childhood and adolescence. Health promotion efforts in childhood targeting PA and its psychosocial and social-environmental correlates might have favourable effects in later years.

Sociospatial distribution of access to facilities for moderate and vigorous intensity physical activity in Scotland by different modes of transport

Karen Lamb — 2012-05-08T00:00:00Z

Background: People living in neighbourhoods of lower socioeconomic status have been shown to have higher rates of obesity and a lower likelihood of meeting physical activity recommendations than their more affluent counterparts. This study examines the sociospatial distribution of access to facilities for moderate or vigorous intensity physical activity in Scotland and whether such access differs by the mode of transport available and by Urban Rural Classification. Methods: A database of all fixed physical activity facilities was obtained from the national agency for sport in Scotland. Facilities were categorised into light, moderate and vigorous intensity activity groupings before being mapped. Transport networks were created to assess the number of each type of facility accessible from the population weighted centroid of each small area in Scotland on foot, by bicycle, by car and by bus. Multilevel modelling was used to investigate the distribution of the number of accessible facilities by small area deprivation within urban, small town and rural areas separately, adjusting for population size and local authority. Results: Prior to adjustment for Urban Rural Classification and local authority, the median number of accessible facilities for moderate or vigorous intensity activity increased with increasing deprivation from the most affluent or second most affluent quintile to the most deprived for all modes of transport. However, after adjustment, the modelling results suggest that those in more affluent areas have significantly higher access to moderate and vigorous intensity facilities by car than those living in more deprived areas. Conclusions: The sociospatial distributions of access to facilities for both moderate intensity and vigorous intensity physical activity were similar. However, the results suggest that those living in the most affluent neighbourhoods have poorer access to facilities of either type that can be reached on foot, by bicycle or by bus than those living in less affluent areas. This poorer access from the most affluent areas appears to be reversed for those with access to a car.

Active video games: the mediating effect of aerobic fitness on body composition

Ralph Maddison — 2012-05-03T00:00:00Z

Background: Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToyTM) intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI), which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating effects of the secondary outcomes.ObjectiveTo identify mediators of the effect of an active video games intervention on body composition. Methods: Data from a two-arm parallel randomized controlled trial of an active video game intervention (n = 322) were analyzed. The primary outcome was change from baseline in BMI. A priori secondary outcomes were considered as potential mediators of the intervention on BMI, including aerobic fitness (VO2Max), time spent in moderate-to-vigorous physical activity (MVPA), and food snacking at 24 weeks. Results: Only aerobic fitness at 24 weeks met the conditions for mediation, and was a significant mediator of BMI. Conclusion: Playing active video games can have a positive effect on body composition in overweight or obese children and this effect is most likely mediated through improved aerobic fitness. Future trials should examine other potential mediators related to this type of intervention.Trial registrationAustralian New Zealand Clinical Trials RegistryWebsite: http://www.anzctr.org.auStudy ID number: ACTRN12607000632493

Overweight and obese adolescents: what turns them off physical activity?

Ivana Stankov — 2012-05-03T00:00:00Z

A systematic review of qualitative studies was undertaken to understand the barriers to physical activity experienced by adolescents who were overweight or obese. From a search of electronic databases and 'grey' literature, published between 1950 and 2009, 15 studies met the inclusion criteria. Bronfenbrenner's model of human development provided an ecological lens for identifying and synthesising barriers to physical activity. Two reviewers appraised study quality. Miles and Huberman's cross-case analysis was integrated with thematic networking to synthesize the individual, interpersonal and environmental level barriers for boys and girls of different ethnicities and socioeconomic status, across school settings and generalised context. Thirty-five barriers were identified, 13 of which occurred in physical activity situations in the school setting, 18 were not linked to a specific setting, and the remainder were common across both contexts. The fact that these barriers emerged from studies that focused on topics such as victimisation and mental health is particularly poignant and reflects the potentially pervasive influence of adolescent's excessive weight not only in relation to physical activity situations but other aspects of their lives. Furthermore, socioeconomic status and ethnicity was poorly considered, with only one study linking these participant characteristics to quotations and discussing the potential implications. At present, there are few qualitative studies with sufficiently thick description or interpretive validity that provide insight into this vulnerable group of adolescents, and give them a voice to influence policy and practice.

Meta-analysis of internet-delivered interventions to increase physical activity levels

Cally Davies — 2012-04-30T00:00:00Z

Many internet-delivered physical activity behaviour change programs have been developed and evaluated. However, further evidence is required to ascertain the overall effectiveness of such interventions. The objected of the present review was to evaluate the effectiveness of internet-delivered interventions to increase physical activity, whilst also examining the effect of intervention moderators. A systematic search strategy identified relevant studies published in the English-language from Pubmed, Proquest, Scopus, PsychINFO, CINHAL, and Sport Discuss (January 1990 - June 2011). Eligible studies were required to include an internet-delivered intervention, target an adult population, measure and target physical activity as an outcome variable, and include a comparison group that did not receive internet-delivered materials. Studies were coded independently by two investigators. Overall effect sizes were combined based on the fixed effect model. Homogeneity and subsequent exploratory moderator analysis was undertaken. A total of 34 articles were identified for inclusion. The overall mean effect of internet-delivered interventions on physical activity was d = 0.14 (p = 0.00). Fixed-effect analysis revealed significant heterogeneity across studies (Q = 73.75; p = 0.00). Moderating variables such as larger sample size, screening for baseline physical activity levels and the inclusion of educational components significantly increased intervention effectiveness. Results of the meta-analysis support the delivery of internet-delivered interventions in producing positive changes in physical activity, however effect sizes were small. The ability of internet-delivered interventions to produce meaningful change in long-term physical activity remains unclear.

Results from an experimental trial at a Head Start center to evaluate two meal service approaches to increase fruit and vegetable intake of preschool aged children

Lisa Harnack — 2012-04-30T00:00:00Z

Background: Strategies to increase fruit and vegetable consumption of preschool aged children are needed.ObjectivesEvaluate the independent effects of the following meal service strategies on intake of fruits and vegetables of preschool children: 1.) Serving fruits and vegetables in advance of other menu items as part of traditional family style meal service; and 2.) Serving meals portioned and plated by providers. Methods: Fifty-three preschool aged children completed a randomized crossover experiment conducted at a Head Start center in Minneapolis, MN. Over a six week trial period each of the experimental meal service strategies (serving fruits and vegetable first and serving meals portioned by providers) was implemented during lunch service for two one-week periods. Two one-week control periods (traditional family style meal service with all menu items served at once) were also included over the six week trial period. Children's lunch intake was observed as a measure of food and nutrient intake during each experimental condition. Results: Fruit intake was significantly higher (p < 0.01) when fruits and vegetables were served in advance of other meal items (0.40 servings/meal) compared to the traditional family style meal service control condition when they were served in tandem with other menu items (0.32 servings/meal). Intakes of some nutrients found in fruits (vitamin A and folate) were concomitantly higher. In contrast, fruit and vegetable intakes were significantly lower and energy intake significantly higher during the provider portioned compared with control condition. Conclusions: Serving fruits in advance of other meal items may be a low cost easy to implement strategy for increasing fruit intake in young children. However, serving vegetables first does not appear to increase vegetable intake. Results provide support for current recommendations for traditional family style meal service in preschool settings.

Correlates of children's time-specific physical activity: A review of the literature

Rebecca Stanley — 2012-04-30T00:00:00Z

Assessment of correlates of physical activity occurring at different times of the day, locations and contexts, is imperative to understanding children's physical activity behaviour. The purpose of this review was to identify the correlates of children's physical activity (aged 8-14 years) occurring during the school break time and after-school periods. A review was conducted of the peer-reviewed literature, published between 1990 and January 2011. A total of 22 studies (12 school break time studies, 10 after-school studies) were included in the review. Across the 22 studies, 17 studies were cross-sectional and five studies were interventions. In the school break time studies, 39 potential correlates were identified, of which gender and age were consistently associated with school break time physical activity in two or more studies, and family affluence, access to a gym, access to four or more physical activity programs and the condition of a playing field were all associated with school break time physical activity in only one study. Access to loose and fixed equipment, playground markings, size of and access to play space and the length of school break time were all positively associated with changes in school break time physical activity in intervention studies. Thirty-six potential correlates of after-school physical activity were identified. Gender (with boys more active), younger age, lower body mass index (for females), lower TV viewing/playing video games, and greater access to facilities were associated with higher levels of after-school physical activity in two or more studies. Parent supervision was negatively associated with females' after-school physical activity in one study. This review has revealed a relatively small number of studies investigating the school break time and after-school periods in the specified age range and only a few correlates have demonstrated a consistent association with physical activity. This highlights the infancy of this area and a need for further investigation into time-specific physical activity behaviour so that interventions designed for these specific periods can target the important correlates.

Seasonal variation in accelerometer-determined sedentary behaviour and physical activity in children: a review

Carly Rich — 2012-04-30T00:00:00Z

AimTo undertake a review of the methods and findings of published research evaluating the influence of season on accelerometer-determined sedentary behaviour (SB) and physical activity (PA) in children. Methods: A literature search was carried out using PubMed, Embase, Medline and Web of Science up to, and including, June 2011. The search strategy focused on four key elements: children, SB or PA, season and accelerometer. Articles were eligible for inclusion if they were published in English, included healthy study participants aged [less than or equal to] 18 years, reported at least one outcome variable derived from accelerometer-determined measurements, and compared SB or PA between two or more seasons, or controlled for season of measurement. Eligible papers were reviewed and evidence tables compiled reporting on publication year, country studied, study recruitment, consent rate, sample descriptives, study design, accelerometer protocol, valid accelerometer data receipt, season definition, statistical methods and key findings. Results: Sixteen of 819 articles were eligible for inclusion: children aged two to five years, six to twelve, or six to 18 years were included in five, six and five articles respectively. Six articles were from the UK, six from other European countries, three from the USA and one from New Zealand. Study sample sizes ranged from 64 to 5595. PA was reported in all articles but SB in only three. Only four studies were longitudinal and none of these reported SB. Seasonal variation in PA was reported in all UK studies, being highest in summer and lowest in winter. In four non-UK studies seasonal variation in PA was not found. Findings were inconclusive for SB. Conclusion: There is sufficient evidence to support public health interventions aimed at increasing PA during winter in UK children. No conclusions can be drawn regarding the effect of season on children's SB reflecting few studies of small sample size, lack of repeat measures, incomparable definitions of season and inconsistent accelerometer protocols. Future research should determine factors that drive seasonal patterns in PA and SB in children such as age, sex, and geographic and climatic setting to inform interventions and target populations.

Family leadership styles and adolescent dietary and physical activity behaviors: a cross-sectional study

Katie Morton — 2012-04-30T00:00:00Z

Background: Transformational leadership is conceptualized as a set of behaviors designed to inspire, energize and motivate others to achieve higher levels of functioning, and is associated with salient health-related outcomes in organizational settings. Given (a) the similarities that exist between leadership within organizational settings and parenting within families, and (b) the importance of the family environment in the promotion of adolescent health-enhancing behaviors, the purpose of this exploratory study was to examine the cross-sectional relationships between parents' transformational leadership behaviors and adolescent dietary and physical activity behaviors. Methods: 857 adolescents (aged 13-15, mean age = 14.70 yrs) completed measures of transformational parenting behaviors, healthful dietary intake and leisure-time physical activity. Regression analyses were conducted to examine relationships between family transformational leadership and adolescent health outcomes. A further 'extreme group analysis' was conducted by clustering families based on quartile splits. A MANCOVA (controlling for child gender) was conducted to examine differences between families displaying (a) HIGH levels of transformational parenting (consistent HIGH TP), (b) LOW levels of transformational parenting (consistent LOW TP), and (c) inconsistent levels of transformational parenting (inconsistent HIGH-LOW TP). Results: Results revealed that adolescents' perceptions of family transformational parenting were associated with both healthy dietary intake and physical activity. Adolescents who perceived their families to display the highest levels of transformational parenting (HIGH TP group) displayed greater healthy eating and physical activity behaviors than adolescents who perceived their families to display the lowest levels of transformational parenting behaviors (LOW TP group). Adolescents who perceived their families to display inconsistent levels of transformational parenting behaviors (HIGH-LOW TP group) displayed the same levels of healthy eating behaviors as those adolescents from the LOW TP group. For physical activity behaviors, adolescents who perceived their families to display inconsistent levels of transformational parenting behaviors (HIGH-LOW TP group) did not differ in terms of physical activity than those in either the HIGH TP or LOW TP group. Conclusions: Family transformational parenting behaviors were positively associated with both healthful dietary intake and leisure-time physical activity levels amongst adolescents. The findings suggest that transformational leadership theory is a useful framework for understanding the relationship between family leadership behaviors and adolescent health outcomes.

Physical activity levels six months after a randomised controlled physical activity intervention for Pakistani immigrant men living in Norway

Eivind Andersen — 2012-04-26T00:00:00Z

Background: To our knowledge, no studies have aimed at improving the PA level in south Asian immigrant men residing in Western countries, and few studies have considered the relevance of SCT constructs to the PA behaviour of this group in the long term. The observed low physical activity (PA) level among south Asian immigrants in Western countries may partly explain the high prevalence of cardiovascular diseases (CVD) and type 2 diabetes (T2D) in this group. We have shown previously in a randomised controlled trial, the Physical Activity and Minority Health study (PAMH) that a social cognitive based intervention can beneficially influence PA level and subsequently reduce waist circumference and insulin resistance in the short-term. In an extended follow-up of the PAMH study: we aimed 1) to determine if the intervention produced long-term positive effects on PA level six months after intervention (follow-up 2 (FU2)), and 2) to identify the social cognitive mediators of any intervention effects. Methods: Physically inactive Pakistani immigrant men (n = 150) who were free of CVD and T2D were randomly assigned to a five months PA intervention or a control group. Six months after the intervention ended, we telephoned all those who attended FU1 and invited them for a second follow-up test (FU2) (n = 133). PA was measured using ActiGraph accelerometers. Statistical differences between groups were determined by use of ANCOVA. Results: Significant differences (baseline to FU2) between the groups were found for all PA variables (e.g., total PA level, sedentary time, PA intensity). Support from family and outcome expectancies increased more in the intervention group compared with the control group. Self-efficacy did not differ significantly between groups. Conclusions: Our results show that a multi component PA programme can increase PA over the short and long term in a group of immigrant Pakistani men. However, we could not identify the factors that mediated these changes in PA.Protocol ID07112001326, NCT ID: NCT00539903