PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (996)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
more »
1.  Changes in weight, physical activity, sedentary behaviour and dietary intake during the transition to higher education: a prospective study 
Background
The transition to higher education involves a significant life change and might be accompanied with less healthy behaviours. However, the only longitudinal study that spanned the period from high school to college/university was limited to self-reported weight. Other studies assessed objective weight, but only at the start of the first semester at college/university and used retrospective questionnaires to asses health behaviours in high school. This study investigated changes in objectively assessed weight and prospective health behaviours during the transition from high school to college/university in Belgian students and examined which health behaviour changes were related to weight change.
Methods
A sample of 291 students was followed from the final year of high school until the second year of college/university. Body mass index (BMI) and waist circumference were measured objectively. Physical activity, sedentary behaviours and dietary intake were estimated using validated questionnaires. In order to study changes in BMI and health behaviours, 2 × 2 (time × gender) Repeated Measures ANOVA analyses were conducted. A stepwise multiple regression analysis was executed to investigate the association between changes in health behaviours and BMI changes, and the moderating effect of gender.
Results
On average students gained 2.7 kg with a greater increase in boys (boys: 4.2 kg, girls: 1.9 kg). Active transportation and sport participation decreased. Some sedentary behaviours (watching TV/DVD, playing computer games) decreased, while others (internet use, studying) increased. Consumption of different foods decreased, while alcohol consumption increased. A higher decrease in sport participation, a higher increase in internet use and a lower increase in studying were related to a greater increase in BMI. An increase in alcohol consumption only contributed to weight gain in boys, whereas a decrease in fruit/vegetable intake only contributed to weight gain in girls.
Conclusion
We can conclude that the transition to higher education is an at risk period for weight gain and unfavourable changes in health behaviours. Interventions to prevent weight gain in college/university students should therefore already start in high school with a somewhat different focus in boys versus girls.
doi:10.1186/s12966-015-0173-9
PMCID: PMC4332914
Body mass index; Freshman 15; Health behaviour; Longitudinal study; Students; Body weight changes
2.  Categorisation of built environment characteristics: the trouble with tertiles 
Background
In the analysis of the effect of built environment features on health, it is common for researchers to categorise built environment exposure variables based on arbitrary percentile cut-points, such as median or tertile splits. This arbitrary categorisation leads to a loss of information and a lack of comparability between studies since the choice of cut-point is based on the sample distribution.
Discussion
In this paper, we highlight the various drawbacks of adopting percentile categorisation of exposure variables. Using data from the SocioEconomic Status and Activity in Women (SESAW) study from Melbourne, Australia, we highlight alternative approaches which may be used instead of percentile categorisation in order to assess built environment effects on health. We discuss these approaches using an example which examines the association between the number of accessible supermarkets and body mass index.
Summary
We show that alternative approaches to percentile categorisation, such as transformations of the exposure variable or factorial polynomials, can be implemented easily using standard statistical software packages. These procedures utilise all of the available information available in the data, avoiding a loss of power as experienced when categorisation is adopted.We argue that researchers should retain all available information by using the continuous exposure, adopting transformations where necessary.
doi:10.1186/s12966-015-0181-9
PMCID: PMC4335683
Percentile categorisation; Exposure assessment; Built environment; Neighbourhood; Statistical analysis
3.  A novel assessment of adolescent mobility: a pilot study 
Background
The accurate measurement of daily mobility and travel to destinations beyond the residential neighbourhood has been identified as an important but almost systematically overlooked factor when investigating the relationship between exposure to the built environment and physical activity. The recent development of VERITAS – a web-based application nested within a computer-assisted personal interview – allows researchers to assess daily mobility, travel to regular destinations, and perceived neighbourhood boundaries using interactive mapping technology. The aims of this pilot study were to (1) demonstrate the feasibility and functionality of using VERITAS in an adolescent sample, and (2) compare urban form characteristics and geometric features of the perceived neighbourhood with traditional neighbourhood delimitations.
Methods
Data were collected and analysed for twenty-eight participants (14 male, 15.9 ± 1.48 years) in 2013. Participants underwent anthropometric assessment before completing a custom-designed VERITAS protocol under the supervision of trained interview technicians. Regularly visited destinations, school travel routes, transportation modes, travel companions, and perceived neighbourhood boundaries were assessed. Data were imported into ArcGIS and street network distances between the home and each geolocated destination were generated. Convex hull activity spaces were derived from destinations. Urban form variables and geometric characteristics were compared between the perceived neighbourhood, existing meshblocks, 1 mile Euclidean buffers, and 1 km network buffers.
Results
In total, 529 destinations were geolocated, 58% of which were outside the perceived neighbourhood boundary. Active travel was inversely associated with distance to destinations (r = −.43, p < .05) and traveling with adults (r = −.68, p < .01). Urban form and geometric characteristics of the perceived neighbourhood were different from those in other neighbourhood delimitations.
Conclusions
This study demonstrates the feasibility of using VERITAS to assess mobility within adolescent populations. Our results also illustrate the potential novelty and use of user-defined spaces, and highlight the limitations of relying on restricted definitions of place (i.e., administrative or residential-focused neighbourhoods) when assessing environmental exposure.
doi:10.1186/s12966-015-0176-6
PMCID: PMC4336506
Active travel; Adolescent; Built environment; Mobility; Neighbourhood definition; Physical activity; Spatial polygamy; VERITAS; SoftGIS
4.  Identifying risk profiles for childhood obesity using recursive partitioning based on individual, familial, and neighborhood environment factors 
Background
Few studies consider how risk factors within multiple levels of influence operate synergistically to determine childhood obesity. We used recursive partitioning analysis to identify unique combinations of individual, familial, and neighborhood factors that best predict obesity in children, and tested whether these predict 2-year changes in body mass index (BMI).
Methods
Data were collected in 2005–2008 and in 2008–2011 for 512 Quebec youth (8–10 years at baseline) with a history of parental obesity (QUALITY study). CDC age- and sex-specific BMI percentiles were computed and children were considered obese if their BMI was ≥95th percentile. Individual (physical activity and sugar-sweetened beverage intake), familial (household socioeconomic status and measures of parental obesity including both BMI and waist circumference), and neighborhood (disadvantage, prestige, and presence of parks, convenience stores, and fast food restaurants) factors were examined. Recursive partitioning, a method that generates a classification tree predicting obesity based on combined exposure to a series of variables, was used. Associations between resulting varying risk group membership and BMI percentile at baseline and 2-year follow up were examined using linear regression.
Results
Recursive partitioning yielded 7 subgroups with a prevalence of obesity equal to 8%, 11%, 26%, 28%, 41%, 60%, and 63%, respectively. The 2 highest risk subgroups comprised i) children not meeting physical activity guidelines, with at least one BMI-defined obese parent and 2 abdominally obese parents, living in disadvantaged neighborhoods without parks and, ii) children with these characteristics, except with access to ≥1 park and with access to ≥1 convenience store. Group membership was strongly associated with BMI at baseline, but did not systematically predict change in BMI.
Conclusion
Findings support the notion that obesity is predicted by multiple factors in different settings and provide some indications of potentially obesogenic environments. Alternate group definitions as well as longer duration of follow up should be investigated to predict change in obesity.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-015-0175-7) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-015-0175-7
PMCID: PMC4336734
Built environment; Body mass index; Familial risk; Food environment; Neighborhood characteristics; Obesity; Physical activity; Recursive partitioning analysis; Socioecological model
5.  Physical activity and sedentary behavior patterns using accelerometry from a national sample of United States adults 
Background
This study described the patterns of accelerometer-determined physical activity and sedentary behavior among adults using a nationally representative sample from the United States.
Methods
Using 2003-2006 National Health and Nutrition Examination Survey (NHANES) data, 7931 adults at least 18 years old wore an ActiGraph accelerometer for one week, providing at least 3 days of wear for >=8 hours/day. Cutpoints defined moderate to vigorous physical activity (MVPA; >= 2020 and >=760 counts/minute), vigorous physical activity (> = 5999 counts/minute), and sedentary behavior (<100 counts/minute). Latent class analysis (LCA) was used to estimate patterns of physical activity and sedentary behavior. All estimates were weighted to reflect the United States population.
Results
For weighted percent of MVPA out of total wearing time, 5 classes were identified from least to most active: 65.3% of population (weighted mean 9.3 minutes/day), 24.9% (32.1 minutes/day), 3.2% that was low on the weekdays but much higher on the weekends (52.0 minutes/day), 5.9% (59.9 minutes/day), and 0.7% in the highest class (113.6 minutes/day). Using the lower MVPA threshold, 6 classes emerged with each class ranging in population from 1.2% to 43.6%. A vigorous activity class could not be derived due to low prevalence. For weighted percent of sedentary behavior out of total wearing time, 5 classes were identified from most to least sedentary: 6.3% of population (weighted mean 660.2 minutes/day), 25.1% (546.8 minutes/day), 37.7% (453.9 minutes/day), 24.0% (354.8 minutes/day), and 7.0% (256.3 minutes/day). Four of the classes showed generally similar results across every day of the week, with the absolute percents differing across classes. In contrast, the least sedentary class showing a marked rise in percent of time spent in sedentary behavior on the weekend (weighted mean 336.7-346.5 minutes/day) compared to weekdays (weighted mean 255.2-292.4 minutes/day).
Conclusion
The LCA models provided a data reduction process to identify patterns using minute-by-minute accelerometry data in order to explore meaningful contrasts. The models supported 5 or 6 distinct patterns for MVPA and sedentary behavior. These physical activity and sedentary behavior patterns can be used as intervention targets and as independent or dependent variables in future studies of correlates, determinants, or outcomes.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-015-0183-7) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-015-0183-7
PMCID: PMC4336769
Accelerometry; Latent class analysis; Moderate to vigorous physical activity; Surveillance; Weekend warrior
6.  Obesity prevention and the Health promoting Schools framework: essential components and barriers to success 
Background
Obesity is an important public health issue. Finding ways to increase physical activity and improve nutrition, particularly in children, is a clear priority. Our Cochrane review of the World Health Organization’s Health Promoting Schools (HPS) framework found this approach improved students’ physical activity and fitness, and increased fruit and vegetable intake. However, there was considerable heterogeneity in reported impacts. This paper synthesises process evaluation data from these studies to identify factors that might explain this variability.
Methods
We searched 20 health, education and social-science databases, and trials registries and relevant websites in 2011 and 2013. No language or date restrictions were applied. We included cluster randomised controlled trials. Participants were school students aged 4-18 years. Studies were included if they: took an HPS approach (targeting curriculum, environment and family/community); focused on physical activity and/or nutrition; and presented process evaluation data. A framework approach was used to facilitate thematic analysis and synthesis of process data.
Results
Twenty-six studies met the inclusion criteria. Most were conducted in America or Europe, with children aged 12 years or younger.
Although interventions were acceptable to students and teachers, fidelity varied considerably across trials. Involving families, while an intrinsic element of the HPS approach, was viewed as highly challenging. Several themes emerged regarding which elements of interventions were critical for success: tailoring programmes to individual schools’ needs; aligning interventions with schools’ core aims; working with teachers to develop programmes; and providing on-going training and support. An emphasis on academic subjects and lack of institutional support were barriers to implementation.
Conclusions
Stronger alliances between health and education appear essential to intervention success. Researchers must work with schools to develop and implement interventions, and to evaluate their impact on both health and educational outcomes as this may be a key determinant of scalability. If family engagement is attempted, better ways to achieve this must be developed and evaluated. Further evaluations of interventions to promote physical activity and nutrition during adolescence are needed. Finally, process evaluations must move beyond simple measures of acceptability/fidelity to include detailed contextual information to illuminate exactly what works, for whom, in what contexts and why.
doi:10.1186/s12966-015-0167-7
PMCID: PMC4330926
Children; Adolescents; Interventions; Schools; Physical activity; Healthy eating; Process evaluation; Health promoting Schools
7.  Organizing “Play Streets” during school vacations can increase physical activity and decrease sedentary time in children 
A Play Street is a street that is reserved for children’s safe play for a specific period during school vacations. It was hypothesized that a Play Street near children’s home can increase their moderate- to vigorous-intensity physical activity (MVPA) and decrease their sedentary time. Therefore, the aim of this study was to investigate the effect of Play Streets on children’s MVPA and sedentary time.
A nonequivalent control group pretest-posttest design was used to determine the effects of Play Streets on children’s MVPA and sedentary time. Data were collected in Ghent during July and August 2013. The study sample consisted of 126 children (54 from Play streets, 72 from control streets). Children wore an accelerometer for 8 consecutive days and their parents fill out a questionnaire before and after the measurement period. During the intervention, streets were enclosed and reserved for children’s play. Four-level (neighborhood – household – child – time of measurement (no intervention or during intervention)) linear regression models were conducted in MLwiN to determine intervention effects.
Positive intervention effects were found for sedentary time (β = -0.76 ± 0.39; χ2 = 3.9; p = 0.05) and MVPA (β = 0.82 ± 0.43; χ2 = 3.6; p = 0.06). Between 14h00 and 19h00, MVPA from children living in Play Streets increased from 27 minutes during normal conditions to 36 minutes during the Play Street intervention, whereas control children’s MVPA decreased from 27 to 24 minutes. Sedentary time from children living in the Play Street decreased from 146 minutes during normal conditions to 138 minutes during the Play Street intervention, whereas control children’s sedentary time increased from 156 minutes to 165 minutes. The intervention effects on MVPA (β = -0.62 ± 0.25; χ2 = 6.3; p = 0.01) and sedentary time (β = 0.85 ± 0.0.33; χ2 = 6.6; p = 0.01) remained significant when the effects were investigated during the entire day, indicating that children did not compensate for their increased MVPA and decreased sedentary time, during the rest of the day.
Creating a safe play space near urban children’s home by the Play Street intervention is effective in increasing children’s MVPA and decreasing their sedentary time.
doi:10.1186/s12966-015-0171-y
PMCID: PMC4334854
Active play; Vacation; Children; Neighborhood; Intervention
8.  Food neophobia and its association with diet quality and weight in children aged 24 months: a cross sectional study 
Background
Food neophobia, the rejection of unknown or novel foods, may result in poor dietary patterns. This study investigates the cross-sectional relationship between neophobia in children aged 24 months and variety of fruit and vegetable consumption, intake of discretionary foods and weight.
Methods
Secondary analysis of data from 330 parents of children enrolled in the NOURISH RCT (control group only) and SAIDI studies was performed using data collected at child age 24 months. Neophobia was measured at 24 months using the Child Food Neophobia Scale (CFNS). The cross-sectional associations between total CFNS score and fruit and vegetable variety, discretionary food intake and BMI (Body Mass Index) Z-score were examined via multiple regression models; adjusting for significant covariates.
Results
At 24 months, more neophobic children were found to have lower variety of fruits (β = −0.16, p = 0.003) and vegetables (β = −0.29, p < 0.001) but have a greater proportion of daily energy from discretionary foods (β = 0.11, p = 0.04). There was no significant association between BMI Z-score and CFNS score.
Conclusions
Neophobia is associated with poorer dietary quality. Results highlight the need for interventions to (1) begin early to expose children to a wide variety of nutritious foods before neophobia peaks and (2) enable health professionals to educate parents on strategies to overcome neophobia.
doi:10.1186/s12966-015-0184-6
PMCID: PMC4335451
Children; Neophobia; Diet; Weight; Fruit and vegetables; Discretionary foods
9.  Improving wear time compliance with a 24-hour waist-worn accelerometer protocol in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) 
Background
We compared 24-hour waist-worn accelerometer wear time characteristics of 9–11 year old children in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) to similarly aged U.S. children providing waking-hours waist-worn accelerometer data in the 2003–2006 National Health and Nutrition Examination Survey (NHANES).
Methods
Valid cases were defined as having ≥4 days with ≥10 hours of waking wear time in a 24-hour period, including one weekend day. Previously published algorithms for extracting total sleep episode time from 24-hour accelerometer data and for identifying wear time (in both the 24-hour and waking-hours protocols) were applied. The number of valid days obtained and a ratio (percent) of valid cases to the number of participants originally wearing an accelerometer were computed for both ISCOLE and NHANES. Given the two surveys’ discrepant sampling designs, wear time (minutes/day, hours/day) from U.S. ISCOLE was compared to NHANES using a meta-analytic approach. Wear time for the 11 additional countries participating in ISCOLE were graphically compared with NHANES.
Results
491 U.S. ISCOLE children (9.92±0.03 years of age [M±SE]) and 586 NHANES children (10.43 ± 0.04 years of age) were deemed valid cases. The ratio of valid cases to the number of participants originally wearing an accelerometer was 76.7% in U.S. ISCOLE and 62.6% in NHANES. Wear time averaged 1357.0 ± 4.2 minutes per 24-hour day in ISCOLE. Waking wear time was 884.4 ± 2.2 minutes/day for U.S. ISCOLE children and 822.6 ± 4.3 minutes/day in NHANES children (difference = 61.8 minutes/day, p < 0.001). Wear time characteristics were consistently higher in all ISCOLE study sites compared to the NHANES protocol.
Conclusions
A 24-hour waist-worn accelerometry protocol implemented in U.S. children produced 22.6 out of 24 hours of possible wear time, and 61.8 more minutes/day of waking wear time than a similarly implemented and processed waking wear time waist-worn accelerometry protocol. Consistent results were obtained internationally. The 24-hour protocol may produce an important increase in wear time compliance that also provides an opportunity to study the total sleep episode time separate and distinct from physical activity and sedentary time detected during waking-hours.
Trial registration
ClinicalTrials.gov NCT01722500.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-015-0172-x) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-015-0172-x
PMCID: PMC4328595
Accelerometry; Measurement; Physical activity; Exercise; Sedentary time
10.  Models accounting for intention-behavior discordance in the physical activity domain: a user’s guide, content overview, and review of current evidence 
There is a growing concern among researchers with the limited effectiveness and yet subsequent stagnation of theories applied to physical activity (PA). One of the most highlighted areas of concern is the established gap between intention and PA, yet the considerable use of models that assume intention is the proximal antecedent of PA. The objective of this review was to: 1) provide a guide and thematic analysis of the available models that include constructs that address intention-behavior discordance and 2) highlight the evidence for these structures in the PA domain. A literature search was conducted among 13 major databases to locate relevant models and PA studies published before August 2014. Sixteen models were identified and nine overall themes for post-intentional constructs were created. Of the 16 models, eight were applied to 36 PA studies. Early evidence supported maintenance self-efficacy, behavioral regulation strategies, affective judgments, perceived control/opportunity, habit, and extraversion as reliable predictors of post-intention PA. Several intention-behavior discordance models exist within the literature, but are not used frequently. Further efforts are needed to test these models, preferably with experimental designs.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-015-0168-6) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-015-0168-6
PMCID: PMC4328062
Theory; Intention-behavior gap; Volition; Post-intention; Exercise; Action control
11.  A critical analysis of the cycles of physical activity policy in England 
Background
There has been increasing focus on the importance of national policy to address population levels of physical inactivity. Components of a comprehensive national physical activity policy framework include: 1) national recommendations on physical activity levels; 2) setting population goals and targets; 3) surveillance or health monitoring systems; and 4) public education. The aim of the current paper was to analyse the policy actions which have addressed each of these elements in England and to identify areas of progress and remaining challenges.
Methods
A literature search was undertaken to identify past and present documents relevant to physical activity policy in England. Each document was analysed to identify content relevant to the four key elements of policy which formed the focus of the current research.
Results
Physical activity recommendations are an area where England has demonstrated a robust scientific approach and good practice; however, the physical activity campaigns in England have not been sufficiently sustained to achieve changes in social norms and behaviour. The setting of physical activity targets has been unrealistic and continuous changes to national surveillance measures have presented challenges for monitoring trends over time.
Conclusions
Overall, physical activity policy in England has fluctuated over the past two decades. The variations and cycles in policy reflect some of the challenges in implementing and sustaining physical activity policy in the face of political changes, changes in government direction, and changing opportunities to profile active lifestyles.
doi:10.1186/s12966-015-0169-5
PMCID: PMC4318185  PMID: 25638442
Physical activity; Policy; Recommendations; Surveillance; Public education
12.  Determinants of dietary behavior among youth: an umbrella review 
Background
The literature on determinants of dietary behavior among youth is extensive and unwieldy. We conducted an umbrella review or review-of-reviews to present a comprehensive overview of the current knowledge.
Methods
Therefore, we included systematic reviews identified in four databases (i.e. PubMed, PsycINFO, The Cochrane Library and Web of Science) that summarized determinants of observable child and adolescent dietary behaviors. Data extraction included a judgment of the importance of determinants, strength of evidence and evaluation of the methodological quality of the eligible reviews.
Results
In total, 17 reviews were considered eligible. Whereas social-cognitive determinants were addressed most intensively towards the end of the 20th century, environmental determinants (particularly social and physical environmental) have been studied most extensively during the past decade, thereby representing a paradigm shift.
With regard to environmental determinants, mixed findings were reported. Sedentary behavior and intention were found to be significant determinants of a wide range of dietary behaviors in most reviews with limited suggestive evidence due to the cross-sectional study designs. Other potential determinants such as automaticity, self-regulation and subjective norm have been studied in relatively few studies, but results are promising.
Conclusion
The multitude of studies conducted on potential determinants of dietary behavior provides quite convincing evidence of the importance of several determinants (i.e. quite some variables were significantly related to dietary behavior). However, because of the often used weak research designs in the studies covered in the available reviews, the evidence for true determinants is suggestive at best.
doi:10.1186/s12966-015-0164-x
PMCID: PMC4328037  PMID: 25638322
Youth; Determinants; Dietary behavior; Umbrella review
13.  Understanding gender norms, nutrition, and physical activity in adolescent girls: a scoping review 
Public health is currently focused on childhood obesity, and the associated behaviors of physical activity and nutrition. Canadian youth are insufficiently active and do not meet nutritional guidelines. This is of particular concern for adolescent girls, as they are less active than boys, become less active as they age, and engage in unhealthy weight control behaviors. The purpose of this review is to determine what is known from the existing literature about how gender norms are understood in relation to the health-related behaviors of PA and nutrition in young girls. This scoping review follows the framework of Arksey and O’Malley, involving defining a research question, study identification and selection, charting, interpretation, summarizing, and reporting. In total, 28 documents are reviewed, and characteristics are summarized quantitatively and qualitatively. Five major themes are identified: (1) Girls’ relationships with PA are complex and require negotiating gender roles, (2) the literature focuses on dieting rather than nutrition, (3) appearance and perceptions influence behaviors, (4) “body” focused discourse is significant to girls’ experiences, and (5) social influences, institutions, and environments are influential and may offer opportunity for future research and action. Gaps in the literature are identified and discussed. It is concluded that young girls’ activity and nutrition is affected by gender norms and feminine ideals through complex negotiations, perceptions, body-centered discourse, and societal influences.
doi:10.1186/s12966-015-0166-8
PMCID: PMC4310022  PMID: 25616739
Gender norms; Physical activity; Nutrition; Adolescent girls; Scoping study
14.  Testing for baseline differences in randomized controlled trials: an unhealthy research behavior that is hard to eradicate 
Background
According to the CONSORT statement, significance testing of baseline differences in randomized controlled trials should not be performed. In fact, this practice has been discouraged by numerous authors throughout the last forty years. During that time span, reporting of baseline differences has substantially decreased in the leading general medical journals. Our own experience in the field of nutrition behavior research however, is that co-authors, reviewers and even editors are still very persistent in their demand for these tests. The aim of this paper is therefore to negate this demand by providing clear evidence as to why testing for baseline differences between intervention groups statistically is superfluous and why such results should not be published.
Discussion
Testing for baseline differences is often propagated because of the belief that it shows whether randomization was successful and it identifies real or important differences between treatment arms that should be accounted for in the statistical analyses. Especially the latter argument is flawed, because it ignores the fact that the prognostic strength of a variable is also important when the interest is in adjustment for confounding. In addition, including prognostic variables as covariates can increase the precision of the effect estimate. This means that choosing covariates based on significance tests for baseline differences might lead to omissions of important covariates and, less importantly, to inclusion of irrelevant covariates in the analysis. We used data from four supermarket trials on the effects of pricing strategies on fruit and vegetables purchases, to show that results from fully adjusted analyses sometimes do appreciably differ from results from analyses adjusted for significant baseline differences only. We propose to adjust for known or anticipated important prognostic variables. These could or should be pre-specified in trial protocols. Subsequently, authors should report results from the fully adjusted as well as crude analyses, especially for dichotomous and time to event data.
Summary
Based on our arguments, which were illustrated by our findings, we propose that journals in and outside the field of nutrition behavior actively adopt the CONSORT 2010 statement on this topic by not publishing significance tests for baseline differences anymore.
doi:10.1186/s12966-015-0162-z
PMCID: PMC4310023  PMID: 25616598
Epidemiology; Methods; Reporting; Nutrition behavior research; Statistical analyses
15.  Objectively measured physical activity in two-year-old children – levels, patterns and correlates 
Background
The aim was to describe levels, patterns and correlates of physical activity and sedentary behavior in a sample of Swedish children, two years of age, with normal weight, overweight and obese parents.
Methods
Data from 123 children, 37 with normal-weight parents and 86 with overweight/obese parents, enrolled in the Early Stockholm Obesity Prevention Project study was used. Children wore an Actigraph GT3X+ accelerometer for seven days. Average activity (counts per minute), number of steps and time spent in low and high-intensity physical activity and in sedentary was assessed. Differences between weekdays and weekend days were examined as were correlations with sex, body mass index (BMI), motor skills and family-related factors.
Results
Children were active at high intensity 11% of the day. On average 55% of the day was spent being sedentary. Number of steps and time in low-intensity physical activity differed between weekdays and weekend days: on weekdays, 363 more steps (p = 0.01) and six more minutes in low physical activity (p = 0.04). No differences were found for any physical activity or sedentary behavior variable by sex, BMI, motor skills or any family-related variable (p = 0.07 – 0.95).
Conclusions
Two-year-old children have an intermittent activity pattern, that is almost similar on weekdays and they spend about half of the daytime active. The absence of any association with sex, BMI, motor skills or parental factors indicates that the individual variation in this age group is primarily due to endogenous factors.
Trial registration
Clinicaltrials.gov: NCT01198847.
doi:10.1186/s12966-015-0161-0
PMCID: PMC4312603  PMID: 25616495
Accelerometer; BMI; Energy expenditure; Motor skills; Toddler
16.  A meta-study of qualitative research examining determinants of children’s independent active free play 
Purpose
To produce a meta-study by completing a systematic review of qualitative research examining determinants of independent active free play in children.
Method
Following systematic electronic and manual searches and application of inclusion/exclusion criteria, 46 studies were retained and subjected to meta-method, meta-theory, and meta-data analyses, followed by a final meta-synthesis.
Results
Identified determinants of independent active free play were child characteristics (age, competence, and gender), parental restrictions (safety concerns and surveillance), neighborhood and physical environment (fewer children to play with, differences in preferences for play spaces between parents and children, accessibility and proximity, and maintenance), societal changes (reduced sense of community, good parenting ideal, changing roles of parents, privatization of playtime and play spaces), and policy issues (need to give children voice). An ecological model depicting these factors, and the relationships therein, was created.
Conclusions
This comprehensive meta-study helps establish a knowledge base for children’s independent active free play research by synthesizing a previously fragmented set of studies. Parents’ perceived safety concerns are the primary barrier to children’s active free play. These safety concerns are moderated by child-level factors (age, competence, gender) and broader social issues. Interventions should focus on community-level solutions that include children’s perspectives. From a methods perspective, the reviewed studies used a range of data collection techniques, but methodological details were often inadequately reported. The theoretical sophistication of research in this area could be improved. To this end, the synthesis reported in this study provides a framework for guiding future research.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-015-0165-9) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-015-0165-9
PMCID: PMC4318368  PMID: 25616690
Meta-synthesis; Safety; Parents; Theory
17.  Processes of behavior change and weight loss in a theory-based weight loss intervention program: a test of the process model for lifestyle behavior change 
Background
Process evaluation is important for improving theories of behavior change and behavioral intervention methods. The present study reports on the process outcomes of a pilot test of the theoretical model (the Process Model for Lifestyle Behavior Change; PMLBC) underpinning an evidence-informed, theory-driven, group-based intervention designed to promote healthy eating and physical activity for people with high cardiovascular risk.
Methods
108 people at high risk of diabetes or heart disease were randomized to a group-based weight management intervention targeting diet and physical activity plus usual care, or to usual care. The intervention comprised nine group based sessions designed to promote motivation, social support, self-regulation and understanding of the behavior change process. Weight loss, diet, physical activity and theoretically defined mediators of change were measured pre-intervention, and after four and 12 months.
Results
The intervention resulted in significant improvements in fiber intake (M between-group difference = 5.7 g/day, p < .001) but not fat consumption (−2.3 g/day, p = 0.13), that were predictive of weight loss at both four months (M between-group difference = −1.98 kg, p < .01; R2 = 0.2, p < 0.005), and 12 months (M difference = −1.85 kg, p = 0.1; R2 = 0.1, p < 0.01). The intervention was successful in improving the majority of specified mediators of behavior change, and the predicted mechanisms of change specified in the PMBLC were largely supported. Improvements in self-efficacy and understanding of the behavior change process were associated with engagement in coping planning and self-monitoring activities, and successful dietary change at four and 12 months. While participants reported improvements in motivational and social support variables, there was no effect of these, or of the intervention overall, on physical activity.
Conclusions
The data broadly support the theoretical model for supporting some dietary changes, but not for physical activity. Systematic intervention design allowed us to identify where improvements to the intervention may be implemented to promote change in all proposed mediators. More work is needed to explore effective mechanisms within interventions to promote physical activity behavior.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0160-6) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0160-6
PMCID: PMC4304200  PMID: 25592314
Physical activity; Diet; Weight loss intervention; Process evaluation
18.  Waste the waist: a pilot randomised controlled trial of a primary care based intervention to support lifestyle change in people with high cardiovascular risk 
Background
In the UK, thousands of people with high cardiovascular risk are being identified by a national risk-assessment programme (NHS Health Checks). Waste the Waist is an evidence-informed, theory-driven (modified Health Action Process Approach), group-based intervention designed to promote healthy eating and physical activity for people with high cardiovascular risk. This pilot randomised controlled trial aimed to assess the feasibility of delivering the Waste the Waist intervention in UK primary care and of conducting a full-scale randomised controlled trial. We also conducted exploratory analyses of changes in weight.
Methods
Patients aged 40–74 with a Body Mass Index of 28 or more and high cardiovascular risk were identified from risk-assessment data or from practice database searches. Participants were randomised, using an online computerised randomisation algorithm, to receive usual care and standardised information on cardiovascular risk and lifestyle (Controls) or nine sessions of the Waste the Waist programme (Intervention). Group allocation was concealed until the point of randomisation. Thereafter, the statistician, but not participants or data collectors were blinded to group allocation. Weight, physical activity (accelerometry) and cardiovascular risk markers (blood tests) were measured at 0, 4 and 12 months.
Results
108 participants (22% of those approached) were recruited (55 intervention, 53 controls) from 6 practices and 89% provided data at both 4 and 12 months. Participants had a mean age of 65 and 70% were male. Intervention participants attended 72% of group sessions. Based on last observations carried forward, the intervention group did not lose significantly more weight than controls at 12 months, although the difference was significant when co-interventions and co-morbidities that could affect weight were taken into account (Mean Diff 2.6Kg. 95%CI: −4.8 to −0.3, p = 0.025). No significant differences were found in physical activity.
Conclusions
The Waste the Waist intervention is deliverable in UK primary care, has acceptable recruitment and retention rates and produces promising preliminary weight loss results. Subject to refinement of the physical activity component, it is now ready for evaluation in a full-scale trial.
Trial registration
Current Controlled Trials ISRCTN10707899.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0159-z) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0159-z
PMCID: PMC4304605  PMID: 25592201
Weight loss; Behaviour change; Diet; Physical activity; Randomised controlled trial; Pilot trial
19.  The Dynamic Family Home: a qualitative exploration of physical environmental influences on children’s sedentary behaviour and physical activity within the home space 
Background
Recent changes in home physical environments, such as decreasing outdoor space and increasing electronic media, may negatively affect health by facilitating sedentariness and reducing physical activity. As children spend much of their time at home they are particularly vulnerable. This study qualitatively explored family perceptions of physical environmental influences on sedentary behaviour and physical activity within the home space.
Methods
Home based interviews were conducted with 28 families with children aged 9–13 years (total n = 74 individuals), living in Perth, Australia. Families were stratified by socioeconomic status and selected to provide variation in housing. Qualitative methods included a family interview, observation and home tour where families guided the researcher through their home, enabling discussion while in the physical home space. Audio recordings were transcribed verbatim and thematically analysed.
Results
Emergent themes related to children’s sedentariness and physical activity included overall size, space and design of the home; allocation of home space; equipment within the home space; perceived safety of the home space; and the changing nature of the home space. Families reported that children’s activity options were limited when houses and yards were small. In larger homes, multiple indoor living rooms usually housed additional sedentary entertainment options, although parents reported that open plan home layouts could facilitate monitoring of children’s electronic media use. Most families reported changing the allocation and contents of their home space in response to changing priorities and circumstances.
Conclusions
The physical home environment can enhance or limit opportunities for children’s sedentary behaviour and physical activity. However, the home space is a dynamic ecological setting that is amenable to change and is largely shaped by the family living within it, thus differentiating it from other settings. While size and space were considered important, how families prioritise the use of their home space and overcome the challenges posed by the physical environment may be of equal or greater importance in establishing supportive home environments. Further research is required to tease out how physical, social and individual factors interact within the family home space to influence children’s sedentary behaviour and physical activity at home.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0157-1) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0157-1
PMCID: PMC4304138  PMID: 25540114
Sedentary behaviour; Physical activity; Children; Environment; Housing; Family interview; Qualitative; Ecological model; Home space
20.  A cluster randomised controlled trial of a telephone-based intervention targeting the home food environment of preschoolers (The Healthy Habits Trial): the effect on parent fruit and vegetable consumption 
Background
The home food environment is an important setting for the development of dietary patterns in childhood. Interventions that support parents to modify the home food environment for their children, however, may also improve parent diet. The purpose of this study was to assess the impact of a telephone-based intervention targeting the home food environment of preschool children on the fruit and vegetable consumption of parents.
Methods
In 2010, 394 parents of 3–5 year–old children from 30 preschools in the Hunter region of Australia were recruited to this cluster randomised controlled trial and were randomly assigned to an intervention or control group. Intervention group parents received four weekly 30-minute telephone calls and written resources. The scripted calls focused on; fruit and vegetable availability and accessibility, parental role-modelling, and supportive home food routines. Two items from the Australian National Nutrition Survey were used to assess the average number of serves of fruit and vegetables consumed each day by parents at baseline, and 2-, 6-, 12-, and 18-months later, using generalised estimating equations (adjusted for baseline values and clustering by preschool) and an intention-to-treat-approach.
Results
At each follow-up, vegetable consumption among intervention parents significantly exceeded that of controls. At 2-months the difference was 0.71 serves (95% CI: 0.58-0.85, p < 0.0001), and at 18-months the difference was 0.36 serves (95% CI: 0.10-0.61, p = 0.0067). Fruit consumption among intervention parents was found to significantly exceed consumption of control parents at the 2-,12- and 18-month follow-up, with the difference at 2-months being 0.26 serves (95% CI: 0.12-0.40, p = 0.0003), and 0.26 serves maintained at 18-months, (95% CI: 0.10-0.43, p = 0.0015).
Conclusions
A four-contact telephone-based intervention that focuses on changing characteristics of preschoolers’ home food environment can increase parents’ fruit and vegetable consumption.
(ANZCTR12609000820202)
doi:10.1186/s12966-014-0144-6
PMCID: PMC4304182  PMID: 25540041
Fruit; Vegetable; Randomised controlled trial; Intervention; Telephone; Family; Home food environment; Preschool; Child
21.  The Dutch Obesity Intervention in Teenagers (DOiT) cluster controlled implementation trial: intervention effects and mediators and moderators of adiposity and energy balance-related behaviours 
Background
The Dutch Obesity Intervention in Teenagers (DOiT) programme is an evidence-based obesity prevention programme tailored to adolescents attending the first two years of prevocational education in the Netherlands. The initial programme showed promising results during an effectiveness trial. The programme was adapted and prepared for nationwide dissemination. To gain more insight into the process of translating evidence-based approaches into ‘real world’ (i.e., ‘natural’) conditions, our research aims were to evaluate the impact of the DOiT-implementation programme on adolescents’ adiposity and energy balance-related behaviours during natural dissemination and to explore the mediating and moderating factors underlying the DOiT intervention effects.
Methods
We conducted a cluster-controlled implementation trial with 20 voluntary intervention schools (n=1002 adolescents) and 9 comparable control schools (n = 484 adolescents). We measured adolescents’ body height and weight, skinfold thicknesses, and waist circumference. We assessed adolescents’ dietary and physical activity behaviours by means of self-report. Data were collected at baseline and at 20-months follow-up. We used multivariable multilevel linear or logistic regression analyses to evaluate the intervention effects and to test the hypothesised behavioural mediating factors. We checked for potential effect modification by gender, ethnicity and education level.
Results
We found no significant intervention effects on any of the adiposity measures or behavioural outcomes. Furthermore, we found no mediating effects by any of the hypothesised behavioural mediators. Stratified analyses for gender showed that the intervention was effective in reducing sugar-containing beverage consumption in girls (B = -188.2 ml/day; 95% CI = -344.0; -32.3). In boys, we found a significant positive intervention effect on breakfast frequency (B = 0.29 days/week; 95% CI = 0.01; 0.58). Stratified analyses for education level showed an adverse intervention effect (B = 0.09; 95% CI = 0.02; 0.16) on BMI z-scores for adolescents attending the vocational education track.
Conclusions
Although not successful in changing adolescents’ adiposity, the DOiT-implementation programme had some beneficial effects on specific obesity-related behaviours in subgroups. This study underlines the difficulty of translating intervention effectiveness in controlled settings to real world contexts. Adaptations to the implementation strategy are needed in order to promote implementation as intended by the teachers.
Trial registration
Current Controlled Trials ISRCTN92755979.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0158-0) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0158-0
PMCID: PMC4304621  PMID: 25539582
Adolescents; Mediation; Intervention; Prevention; Energy balance; Implementation; Dissemination
22.  Breast cancer risk reduction - is it feasible to initiate a randomised controlled trial of a lifestyle intervention programme (ActWell) within a national breast screening programme? 
Background
Breast cancer is the most commonly diagnosed cancer and the second cause of cancer deaths amongst women in the UK. The incidence of the disease is increasing and is highest in women from least deprived areas. It is estimated that around 42% of the disease in post-menopausal women could be prevented by increased physical activity and reductions in alcohol intake and body fatness. Breast cancer control endeavours focus on national screening programmes but these do not include communications or interventions for risk reduction.
This study aimed to assess the feasibility of delivery, indicative effects and acceptability of a lifestyle intervention programme initiated within the NHS Scottish Breast Screening Programme (NHSSBSP).
Methods
A 1:1 randomised controlled trial (RCT) of the 3 month ActWell programme (focussing on body weight, physical activity and alcohol) versus usual care conducted in two NHSSBSP sites between June 2013 and January 2014. Feasibility assessments included recruitment, retention, and fidelity to protocol. Indicative outcomes were measured at baseline and 3 month follow-up (body weight, waist circumference, eating and alcohol habits and physical activity). At study end, a questionnaire assessed participant satisfaction and qualitative interviews elicited women’s, coaches, and radiographers’ experiences. Statistical analysis used Chi squared tests for comparisons in proportions and paired t tests for comparisons of means. Linear regression analyses were performed, adjusted for baseline values, with group allocation as a fixed effect.
Results
A pre-set recruitment target of 80 women was achieved within 12 weeks and 65 (81%) participants (29 intervention, 36 control) completed 3 month assessments. Mean age was 58 ± 5.6 years, mean BMI was 29.2 ± 7.0 kg/m2 and many (44%) reported a family history of breast cancer.
The primary analysis (baseline body weight adjusted) showed a significant between group difference favouring the intervention group of 2.04 kg (95% CI −3.24 kg to −0.85 kg). Significant, favourable between group differences were also detected for BMI, waist circumference, physical activity and sitting time. Women rated the programme highly and 70% said they would recommend it to others.
Conclusions
Recruitment, retention, indicative results and participant acceptability support the development of a definitive RCT to measure long term effects.
Trial registration
The trial was registered with Current Controlled Trials (ISRCTN56223933).
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0156-2) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0156-2
PMCID: PMC4304617  PMID: 25516158
Breast cancer; Physical activity; Body weight; Alcohol; Sedentary time
23.  Social inequalities in young children’s sports participation and outdoor play 
Background
Research on social inequalities in sports participation and unstructured physical activity among young children is scarce. This study aimed to assess the associations of family socioeconomic position (SEP) and ethnic background with children’s sports participation and outdoor play.
Methods
We analyzed data from 4726 ethnically diverse 6-year-old children participating in the Generation R Study. Variables were assessed by parent-reported questionnaires when the child was 6 years old. Low level of outdoor play was defined as outdoor play <1 hour per day. Series of multiple logistic regression analyses were performed to assess associations of family SEP and ethnic background with children’s sports participation and outdoor play.
Results
Socioeconomic inequalities in children’s sports participation were found when using maternal educational level (p < 0.05), paternal educational level (p < 0.05), maternal employment status (p < 0.05), and household income (p < 0.05) as family SEP indicator (less sports participation among low SEP children). Socioeconomic inequalities in children’s outdoor play were found when using household income only (p < 0.05) (more often outdoor play <1 hour per day among children from low income household). All ethnic minority children were significantly more likely to not to participate in sports and play outdoor <1 hour per day compared with native Dutch children. Adjustment for family SEP attenuated associations considerably, especially with respect to sports participation.
Conclusion
Low SEP children and ethnic minority children are more likely not to participate in sports and more likely to display low levels of outdoor play compared with high SEP children and native Dutch children, respectively. In order to design effective interventions, further research, including qualitative studies, is needed to explore more in detail the pathways relating family SEP and ethnic background to children’s sports participation and outdoor play.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0155-3) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0155-3
PMCID: PMC4272790  PMID: 25510552
Socioeconomic; Ethnic; Sports; Outdoor play; Inequalities; Physical activity
24.  Moderators of the longitudinal relationship between the perceived physical environment and outside play in children: the KOALA birth cohort study 
Objectives
Promoting unstructured outside play is a promising vehicle to increase children’s physical activity (PA). This study investigates if factors of the social environment moderate the relationship between the perceived physical environment and outside play.
Study design
1875 parents from the KOALA Birth Cohort Study reported on their child’s outside play around age five years, and 1516 parents around age seven years. Linear mixed model analyses were performed to evaluate (moderating) relationships among factors of the social environment (parenting influences and social capital), the perceived physical environment, and outside play at age five and seven. Season was entered as a random factor in these analyses.
Results
Accessibility of PA facilities, positive parental attitude towards PA and social capital were associated with more outside play, while parental concern and restriction of screen time were related with less outside play. We found two significant interactions; both involving parent perceived responsibility towards child PA participation.
Conclusion
Although we found a limited number of interactions, this study demonstrated that the impact of the perceived physical environment may differ across levels of parent responsibility.
Electronic supplementary material
The online version of this article (doi:10.1186/s12966-014-0150-8) contains supplementary material, which is available to authorized users.
doi:10.1186/s12966-014-0150-8
PMCID: PMC4271341  PMID: 25496008
Moderation; Interaction; Perceived physical environment; Physical activity; Parenting; Social environment
25.  Uptake and factors that influence the use of ‘sit less, move more’ occupational intervention strategies in Spanish office employees 
Background
Little is known about the types of ‘sit less, move more’ strategies that appeal to office employees, or what factors influence their use. This study assessed the uptake of strategies in Spanish university office employees engaged in an intervention, and those factors that enabled or limited strategy uptake.
Methods
The study used a mixed method design. Semi-structured interviews were conducted with academics and administrators (n = 12; 44 ± 12 mean SD age; 6 women) at three points across the five-month intervention, and data used to identify factors that influenced the uptake of strategies. Employees who finished the intervention then completed a survey rating (n = 88; 42 ± 8 mean SD age; 51 women) the extent to which strategies were used [never (1) to usually (4)]; additional survey items (generated from interviewee data) rated the impact of factors that enabled or limited strategy uptake [no influence (1) to very strong influence (4)]. Survey score distributions and averages were calculated and findings triangulated with interview data.
Results
Relative to baseline, 67% of the sample increased step counts post intervention (n = 59); 60% decreased occupational sitting (n = 53). ‘Active work tasks’ and ‘increases in walking intensity’ were the strategies most frequently used by employees (89% and 94% sometimes or usually utilised these strategies); ‘walk-talk meetings’ and ‘lunchtime walking groups’ were the least used (80% and 96% hardly ever or never utilised these strategies). ‘Sitting time and step count logging’ was the most important enabler of behaviour change (mean survey score of 3.1 ± 0.8); interviewees highlighted the motivational value of being able to view logged data through visual graphics in a dedicated website, and gain feedback on progress against set goals. ‘Screen based work’ (mean survey score of 3.2 ± 0.8) was the most significant barrier limiting the uptake of strategies. Inherent time pressures and cultural norms that dictated sedentary work practices limited the adoption of ‘walk-talk meetings’ and ‘lunch time walking groups’.
Conclusions
The findings provide practical insights into which strategies and influences practitioners need to target to maximise the impact of ‘sit less, move more’ occupational intervention strategies.
doi:10.1186/s12966-014-0152-6
PMCID: PMC4266209  PMID: 25490857
Workplace; Occupational sitting; Sedentary behaviour; Walking; Multi-method study; Employee experiences

Results 1-25 (996)