Bettina Bringolf-Isler

Levels of physical activity and sedentary time among 10- to 12-year-old boys and girls across 5 European countries using accelerometers: an observational study within the ENERGY-project

BackgroundThe study aim was to objectively assess levels of sedentary time, light, moderate and vigorous physical activity (PA) among 10-12 year olds across five European countries and to examine differences in sedentary time and PA according to gender and country.Methods686 children (mean age = 11.6 ± 0.8 years, 53% girls, mean BMI = 19.0 ± 3.4 kg/m2) from Belgium, Greece, Hungary, the Netherlands and Switzerland wore Actigraph accelerometers and had at least 2 weekdays with minimum 10 h-wearing time and 1 weekend day with minimum 8 h-wearing time. Data were analyzed using multivariate analyses of covariance.ResultsGirls spent significantly more time sedentary (500 minutes/day) than boys (474 minutes/day) and significantly less time in light (267 minutes/day) and moderate-to-vigorous PA (32 minutes/day) than boys (284 minutes/day; 43 minutes/day respectively; p < 0.001). 4.6% of the girls and 16.8% of the boys met moderate-to-vigorous PA recommendations of at least 60 minutes/day. Greek boys were more sedentary (510 minutes/day; all at p < 0.05) than other boys. Dutch girls were less sedentary (457 minutes/day; all at p < 0.05) than other girls. Swiss girls displayed more moderate-to-vigorous PA (43 minutes/day; at p < 0.05) than other girls.ConclusionsLarge proportions of children across different European countries did not meet PA recommendations and spent a lot of time sedentary. Mean time spent in moderate-to-vigorous PA was significantly lower than the recommended 60 minutes. Obesity prevention programmes focusing on both decreasing sedentary time and increasing light, moderate and vigorous PA are needed for European children, particularly girls.

Trend in active transportation to school among Swiss school children and its associated factors: three cross-sectional surveys 1994, 2000 and 2005

BackgroundGiving the rising trend in childhood obesity in many countries including Switzerland, strategies to increase physical activity such as promoting active school travel are important. Yet, little is known about time trends of active commuting in Swiss schoolchildren and factors associated with changes in walking and biking to school.MethodsBetween 1994 and 2005, information about mobility behaviour of children aged 6-14 years was collected within three Swiss population based national travel behaviour surveys. Mode of transport to school was reported for 4244 children. Weighted multivariate logistic regression analyses were used to assess active school travel time trends and their influencing factors.ResultsMore than 70% of Swiss children walked or biked to school. Nevertheless, the proportion of children biking to school decreased (p = 0.05, linear trend), predominately in urban areas, and motorized transportation increased since 1994 (p = 0.02). Distance to school did not change significantly over time but availability of bikes decreased (p < 0.001) and number of cars per household increased (p < 0.001). The association between survey year and bike use was significantly modified by living in an urban area (OR (95%CI): 1.0, 0.63 (0.44-0.90), 0.71 (0.49-1.03), respectively for 1994, 2000 and 2005) and by distance to school (OR (95%CI): 1.0, 0.65 (0.40-1.05), 0.50 (0.23-0.79) for the same years and for children who lived more than a mile away from school).ConclusionsPrograms to encourage safe biking and to limit car use as mode of transport to school are warranted to stop this trend.

Study protocol of physical activity and sedentary behaviour measurement among schoolchildren by accelerometry - Cross-sectional survey as part of the ENERGY-project

BackgroundPhysical activity and sedentary behaviour among children should be measured accurately in order to investigate their relationship with health. Accelerometry provides objective and accurate measurement of body movement, which can be converted to meaningful behavioural outcomes. The aim of this study was to evaluate the best evidence for the decisions on data collection and data processing with accelerometers among children resulting in a standardized protocol for use in the participating countries.Methods/DesignThis cross-sectional accelerometer study was conducted as part of the European ENERGY-project that aimed to produce an obesity prevention intervention among schoolchildren. Five countries, namely Belgium, Greece, Hungary, Switzerland and the Netherlands participated in the accelerometer study. We used three different Actigraph models-Actitrainers (triaxial), GT3Xs and GT1Ms. Children wore the device for six consecutive days including two weekend days. We selected an epoch length of 15 seconds. Accelerometers were placed at childrens waist at the right side of the body in an elastic belt.In total, 1082 children participated in the study (mean age = 11.7 ± 0.75 y, 51% girls). Non-wearing time was calculated as periods of more than 20 minutes of consecutive zero counts. The minimum daily wearing time was set to 10 hours for weekdays and 8 hours for weekend days. The inclusion criterion for further analysis was having at least three valid weekdays and one valid weekend day. We selected a cut-point (count per minute (cpm)) of <100 cpm for sedentary behaviour, <3000 cpm for light, <5200 cpm for moderate, and >5200 cpm for vigorous physical activity. We also created time filters for school-time during data cleaning in order to explore school-time physical activity and sedentary behaviour patterns in particular.DiscussionThis paper describes the decisions for data collection and processing. Use of standardized protocols would ease future use of accelerometry and the comparability of results between studies.

Self-reported TV and computer time do not represent accelerometer-derived total sedentary time in 10 to 12-year-olds

Screen-time activities are often used as proxies for sedentary time. We studied associations of self-reported television (TV), computer and total screen-time with accelerometer-derived total sedentary time in European children (10-12 years). Analyses showed significant positive associations between TV, computer and total screen-time with total sedentary time for the total sample, however, the explained variance was low and stratified analyses only revealed a significant positive association between total screen-time and total sedentary time in boys and between computer time and total sedentary time in Dutch children. This suggests that self-reported TV and computer time do not adequately reflect total sedentary time in schoolchildren.

Assessment of intensity, prevalence and duration of everyday activities in Swiss school children: a cross-sectional analysis of accelerometer and diary data.

BackgroundAppropriately measuring habitual physical activity (PA) in children is a major challenge. Questionnaires and accelerometers are the most widely used instruments but both have well-known limitations. The aims of this study were to determine activity type/mode and to quantify intensity and duration of childrens everyday PA by combining information of a time activity diary with accelerometer measurements and to assess differences by gender and age.MethodsSchool children (n = 189) aged 6/7 years, 9/10 years and 13/14 years wore accelerometers during one week in winter 2004 and one in summer 2005. Simultaneously, they completed a newly developed time-activity diary during 4 days per week recording different activities performed during each 15 min interval. For each specific activity, the mean intensity (accelerometer counts/min), mean duration per day (min/d) and proportion of involved children were calculated using linear regression models.ResultsFor the full range of activities, boys accumulated more mean counts/min than girls. Adolescents spent more time in high intensity sports activities than younger children (p < 0.001) but this increase was compensated by a reduction in time spent playing vigorously (p = 0.04). In addition, adolescents spent significantly more time in sedentary activities (p < 0.001) and accumulated less counts/min during these activities than younger children (p = 0.007). Among moderate to vigorous activities, children spent most time with vigorous play (43 min/day) and active transportation (56 min/day).ConclusionThe combination of accelerometers and time activity diaries provides insight into age and gender related differences in PA. This information is warranted to efficiently guide and evaluate PA promotion.

Reactivity to accelerometer measurement of children and adolescents

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Occurrence and duration of various operational definitions of sedentary bouts and cross-sectional associations with cardiometabolic health indicators: the ENERGY-project

OBJECTIVE This study examined the occurrence and duration of sedentary bouts and explored the cross-sectional association with health indicators in children applying various operational definitions of sedentary bouts. METHODS Accelerometer data of 647 children (10-13 years old) were collected in five European countries. We analyzed sedentary time (<100 cpm) accumulated in bouts of at least 5, 10, 20 or 30 min based on four operational definitions, allowing 0, 30 or 60s ≥100 cpm within bouts. Health indicators included anthropometrics (i.e. waist circumference and body mass index (BMI)) and in a subsample from two European countries (n=112) fasting capillary blood levels of glucose, C-peptide, high-density- and low-density cholesterol, and triglycerides. Data collection took place from March to July 2010. Associations were adjusted for age, gender, moderate-to-vigorous physical activity, total wear time and country. RESULTS Occurrence of sedentary bouts varied largely between the various definitions. Children spent most of their sedentary time in bouts of ≥5 min while bouts of ≥20 min were rare. Linear regression analysis revealed few significant associations of sedentary time accumulated in bouts of ≥5-30 min with health indicators. Moreover, we found that more associations became significant when allowing no tolerance time within sedentary bouts. CONCLUSION Despite a few significant associations, we found no convincing evidence for an association between sedentary time accumulated in bouts and health indicators in 10-13 year old children.

Differences in weight status and energy-balance related behaviors among schoolchildren in German-speaking Switzerland compared to seven countries in Europe

BackgroundOverweight in children and adolescents have increased significantly and are a major public health problem. To allow international comparisons, Switzerland joined the European study ‘ENERGY’ cross sectional survey consortium that investigated the prevalence of overweight and obesity as well as selected dietary, physical and sedentary behaviors of 10–12 years old pupils across seven other countries in Europe. The aims of the present study was to compare body composition and energy-balance related behaviors of Swiss schoolchildren to those of the seven European ENERGY-countries and to analyze overweight and energy-balance related behaviors of Swiss children according to socio-demographic factors.MethodsA school-based cross-sectional study among 10–12 year old children was conducted in Switzerland and seven other European countries using a standardized protocol. Body height, weight and waist-circumference were measured by trained research assistants. Energy-balance related behaviors –i.e. selected dietary, physical activity and screen-viewing behaviors were assessed by questionnaires. Weight status and behaviors in Switzerland were compared to the seven European ENERGY countries. Within the Swiss sample, analyses stratified by gender, parental education and ethnicity were performed.ResultsData of 546 Swiss children (mean age 11.6±0.8y, 48% girls) were obtained and compared to the ENERGY- results (N=7.148; mean age 11.5±0.8y, 48% girls). In Switzerland significantly less children were overweight (13.9%) or obese (2.3%) compared to the average across the ENERGY-countries (23.7% and 4.7%, respectively), and were even somewhat lower than the ENERGY countries with the lowest prevalence. Sugar sweetened beverage intakes and breakfast habits of Swiss children did not differ significantly from those of ENERGY. However, the mean time devoted by Swiss children to walking or cycling to school and attending sports activities was significantly higher and screen time significantly lower compared to the other ENERGY-countries. Within the Swiss, sample relatively large and consistent differences were observed between children from native and non-native ethnicity.ConclusionsThe prevalence of overweight and obesity among Swiss children are substantial but significantly lower compared to all other European ENERGY-Partners, probably due to the fact that Swiss children were found to be more active and less sedentary comparing to the rest of the European sample.

Associations between Family-Related Factors, Breakfast Consumption and BMI among 10- to 12-Year-Old European Children: The Cross-Sectional ENERGY-Study

Objective To investigate associations of family-related factors with children’s breakfast consumption and BMI-z-score and to examine whether children’s breakfast consumption mediates associations between family-related factors and children’s BMI-z-score. Subjects Ten- to twelve-year-old children (n = 6374; mean age = 11.6±0.7 years, 53.2% girls, mean BMI-z-score = 0.4±1.2) and one of their parents (n = 6374; mean age = 41.4±5.3 years, 82.7% female, mean BMI = 24.5±4.2 kg/m2) were recruited from schools in eight European countries (Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, Spain, and Switzerland). The children self-reported their breakfast frequency per week. The body weight and height of the children were objectively measured. The parents responded to items on family factors related to breakfast (automaticity, availability, encouragement, paying attention, permissiveness, negotiating, communicating health beliefs, parental self-efficacy to address children’s nagging, praising, and family breakfast frequency). Mediation analyses were performed using multi-level regression analyses (child-school-country). Results Three of the eleven family-related variables were significantly associated with children’s BMI-z-score. The family breakfast frequency was negatively associated with the BMI-z-score; permissiveness concerning skipping breakfast and negotiating about breakfast were positively associated with the BMI-z-score. Children’s breakfast consumption was found to be a mediator of the two associations. All family-related variables except for negotiating, praising and communicating health beliefs, were significantly associated with children’s breakfast consumption. Conclusions Future breakfast promotion and obesity prevention interventions should focus on family-related factors including the physical home environment and parenting practices. Nevertheless, more longitudinal research and intervention studies to support these findings between family-related factors and both children’s breakfast consumption and BMI-z-score are needed.

Screen-based sedentary time: Association with soft drink consumption and the moderating effect of parental education in European children: The ENERGY study

Aim The aim of the present study was to explore if children who spend more time on screen-based sedentary behaviors (i.e.TV viewing and computer use) drink more sugar-sweetened soft drinks. The study also assessed whether these associations were independent of individual and home environmental correlates of soft drink consumption and whether they were moderated by parental education. Methods Data were collected from 7886 children participating in the EuropeaN Energy balance Research to prevent excessive weight Gain among Youth (ENERGY) survey conducted in eight European countries. Self-report questionnaires were used. Multilevel linear regression analyses with soft drink consumption as dependent variable, TV viewing and computer use as independent variables and age, gender, parental education, attitude towards soft drinks, self-efficacy, parental modelling, parental rules and home availability of soft drinks as covariates were conducted. Further interactions were tested to explore if these associations were moderated by parental education. Country-specific analyses were conducted. Results In six of the eight included countries, a significant positive association was observed between TV viewing (min/day) and soft drink consumption (ml/day), independent of individual and home environmental correlates of soft drink consumption (B = 0.46 (0.26–0.66) in Greece, B = 0.77 (0.36–1.17) in Norway, B = 0.82 (0.12–1.51) in Hungary, B = 1.06 (0.67–1.46) in Spain, B = 1.21 (0.67–1.74) in Belgium and B = 1.49 (0.72–2.27) in Switzerland). There was no significant association between computer use and soft drink consumption in six of the eight included countries in the final models. Moderation effects of parental education in the association between TV viewing and soft drink consumption were found in Norway and Hungary, the association being stronger among those with low parental education. Conclusions TV viewing appears to be independently associated with soft drink consumption and this association was moderated by parental education in two countries only. Reducing TV time might therefore favorably impact soft drink consumption.