Lifestyle, anthropometric, socio-demographic and perinatal correlates of early adolescence hypertension: The Healthy Growth Study.

BACKGROUND AND AIMS: Various lifestyle, anthropometric, socio-demographic and perinatal characteristics have been separately associated with elevated blood pressure in children and adolescents. The aim of this study was to simultaneously evaluate all potential risk factors and to identify the most dominant correlates of early adolescence hypertension in a large group of school children 9-13 years old. METHODS AND RESULTS: A cross-sectional study with 1444 schoolchildren 9-13 years old, having full data on lifestyle, anthropometric, socio-demographic and perinatal indices, as well as blood pressure measurements. Early adolescents born large for their gestational age (LGA) (OR, 95% C.I. 0.49 (0.25-0.97)), those with higher levels of moderate to vigorous physical activity (MVPA) (OR, 95% C.I. 0.71 (0.53-0.96)) and those of a higher socioeconomic status (SES) (OR, 95% C.I. 0.51 (0.33-0.79)), had lower risk of hypertension, compared with their counterparts with appropriate birth weight, low levels of PA and with low SES respectively, independently of the variables used in the multivariate model. On the other hand, overweight and obese early adolescents (OR, 95% C.I. 2.61 (1.88-3.62)), those with central obesity (OR, 95% C.I. 1.75 (1.12-2.73)) and those having a hypertensive father (OR, 95% C.I. 1.93 (1.20-3.12)) had higher risk of hypertension compared with normal weight early adolescents and those without a family history of hypertension. CONCLUSIONS: Among the parameters examined, early adolescence abnormal body weight and central obesity, low PA, non LGA, low SES family and family history of hypertension were found to be independently associated with higher risk of hypertension. The identified correlates of early adolescence hypertension can be used by public health initiatives for early detection and management of this major public health problem, prioritizing early adolescents and families at the highest possible risk for hypertension.

Effects of hunger state on the brain responses to food cues across the life span.

The abundant exposure to food cues in our environment is one of the main drivers of overconsumption. Food evaluation is important for the regulation of food intake by the brain and it's interaction with hunger state. Children are especially susceptible to food cues. Understanding the mechanisms behind this regulation in healthy individuals across the life span can help to elucidate the mechanisms underlying overconsumption and aid the development of future obesity prevention strategies. Few functional neuroimaging studies have been done in children and elderly. Furthermore, it is unknown how hunger state affects neural food cue reactivity in these groups, since this has not been examined consistently. We examined the effects of hunger state and age on the brain responses to low- and high calorie foods. On two mornings, 122 participants (17 children; 38 teens; 36 adults; 31 elderly) performed a food image viewing task while being scanned using fMRI, either fasted or sated. Hunger induced greater activation during high versus low calorie food image viewing than satiety in the bilateral dorsomedial (dmPFC) and in the right dorsolateral prefrontal cortex (dlPFC) across all age groups. There was no significant main effect of age group on high versus low calorie food image viewing and no interaction between age group and hunger state. The greater activation of the dlPFC across all age groups during high calorie food image viewing in a fasted state might reflect increased inhibitory control in response to these foods. This may underlie the ability to resist overconsumption of high calorie foods. Furthermore, increased medial prefrontal cortex activation during hunger might reflect increased reward value of high calorie foods, which declines with satiation. Further studies are needed to better understand these results. Notably, overweight and obese individuals should be included to examine whether these responses are altered by weight status across the life span.

Prevalence of childhood hypertension and hypertension phenotypes by weight status and waist circumference: the Healthy Growth Study.

PURPOSE: The aim of the present study was to report for the first time the prevalence of hypertension and its phenotypes in obese children and in children with central obesity in a large sample of Greek children. METHODS: A regionally representative sample of 2263 schoolchildren (50.3% boys) (9-13 years) having full data on blood pressure assessment, physical examination, anthropometric, and physical activity participated in a cross-sectional study in Greece. RESULTS: Prevalence of stage 1 and 2 hypertension, of isolated systolic hypertension (ISH) and of combined systolic or diastolic hypertension, was significantly higher for obese children and children on the 3rd tertile of waist circumference in the total sample, as well as in each gender separately. ISH was the most prevalent phenotype reaching 24.3% in obese children and 17.5% in children on the highest tertile of waist circumference. Obese children and children on the highest tertile of waist circumference had 6.31 times and 3.94 times, respectively, higher likelihood to have abnormal systolic or diastolic blood pressure (SBP or DBP) than their normal-weight counterparts. CONCLUSIONS: Prevalence of hypertension and especially ISH in obese children and in children with central obesity in Greece are among the highest reported in Europe. Future public health initiatives should aim to prevent or tackle several underlying factors related to childhood hypertension, focusing primarily on children with excess body weight.

Dietary sources of sugars in adolescents' diet: the HELENA study.

OBJECTIVE: To report dietary sugars consumption and their different types and food sources, in European adolescents. METHODS: Food consumption data of selected groups were obtained from 1630 adolescents (45.6% males, 12.5-17.5 years) from the HELENA study using two nonconsecutive 24-h recalls. Energy intake, total sugars and free sugars were assessed using the HELENA-DIAT software. Multiple regression analyses were performed adjusting for relevant confounders. RESULTS: Total sugars intake (137.5 g/day) represented 23.6% and free sugars (110.1 g/day), 19% of energy intake. Girls had significantly lower intakes of energy, carbohydrates, total sugars and free sugars. 94% of adolescents had a consumption of free sugars above 10% of total energy intake. The main food contributor to free sugars was 'carbonated, soft and isotonic drinks,' followed by 'non-chocolate confectionary' and 'sugar, honey, jam and syrup.' Older boys and girls had significantly higher intakes of free sugars from 'cakes, pies and biscuits.' Free sugars intake was negatively associated with low socioeconomic status for 'non-chocolate confectionary' and 'sugar, honey and jam' groups; with low maternal educational level for carbonated and 'soft drinks,' 'sugar, honey and jam,' 'cakes and pies' and 'breakfast cereals' groups; and with high paternal educational level for 'carbonated and soft drinks' and 'chocolates' group. CONCLUSIONS: The majority (94%) of studied adolescents consumed free sugars above 10% of daily energy intake. Our data indicate a broad variety in foods providing free sugars. Continued efforts are required at different levels to reduce the intake of free sugars, especially in families with a low educational level.

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.

Impact of eating and drinking on body composition measurements by bioelectrical impedance.

BACKGROUND: Bioelectrical impedance analysis would be a more practical tool to measure body composition in clinical settings, dietetic practice and epidemiological studies if patients/subjects did not have to fast before measurements. The present study assessed whether the ingestion of food or drink had any biologically significant effect on bioimpedance measurements and body composition by the foot-to-foot method. METHODS: Fifty-five healthy adults [30 males and 25 females; mean (SD) age 27.7 (7.1) years; mean (SD)body mass index 24 (3.8) kg m(-2)] were randomly assigned to a 2-day food trial (high-fat meal or high-carbohydrate meal) or a 2-day drink trial (water or high electrolyte drink). Body composition measurements were carried out in the fasting state, immediately after meal consumption and every 30 min for 2 h by the foot-to-foot single frequency bioimpedance technique. RESULTS: Bioimpedance increased significantly after the ingestion of food and fluid, although the changes were small. The electrolyte drink, high-fat and high-carbohydrate meals significantly increased the percentage body fat and fat mass. In all cases, the median percentage changes from baseline were approximately 1% in body fat percentage units. CONCLUSIONS: Although there were statistically significant changes in body composition estimates after food or drink consumption, these were small and within the imprecision of the impedance technique, and so are unlikely to be of clinical significance. The present study suggests that impedance measures of body fatness in clinical settings do not require strict adherence to fasting, and this should increase the opportunities for clinical application.

Conception via in vitro fertilization and delivery by Caesarean section are associated with paediatric asthma incidence.

BACKGROUND: The association between perinatal factors and asthma inception is under rigorous investigation. Nevertheless, evidence of a correlation between asthma, conception via in vitro fertilization (IVF) and delivery through Caesarean section (C-section) is inconclusive. OBJECTIVE: We aimed to assess the relation of asthma incidence with IVF and C-section, after controlling for several potential confounding factors. METHODS: Parent-reported wheeze in the last 12 months (current), wheeze ever, physician-diagnosed asthma, method of conception, and type of delivery were recorded from questionnaires filled in by the parents of 2016 Greek children aged 9-13, (the Healthy Growth Study population). Some perinatal data were recorded from children's medical records and others were reported by parents; anthropometric measurements were also conducted in children. RESULTS: IVF was correlated with physician-diagnosed asthma (OR = 2.25; 95% CI = 1.11-4.56), but not with current/ever wheeze after adjustment for potential confounding factors. After adjustment, C-section was also associated with asthma (OR = 1.39; 95% CI = 1.04-1.87), but not with current/ever wheeze. When the association of both IVF and C-section with asthma was examined in the same multivariate logistic regression model, it was weakened to borderline significance (OR = 2.04; 95% CI = 1-4.15 and OR = 1.34; 95% CI = 1-1.81 respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Conception via IVF and delivery by C-section may predispose children to future asthma development. Either variable could also exert a confounding effect on the link of the other to asthma; this may partially be accountable for inconsistencies in the findings of pertinent studies.

Criterion validity of the Physical Activity Questionnaire for Schoolchildren (PAQ-S) in assessing physical activity levels: the Healthy Growth Study.

AIM: The aim of this paper was to evaluate the criterion validity of the Physical Activity Questionnaire for Schoolchildren (PAQ-S). METHODS: The current study is a subcohort of the Healthy Growth Study, a large-scale cross-sectional study. 202 schoolchildren aged 9-13 years from Greece completed the PAQ-S and wore an accelerometer for 4 consecutive days. Time spent moderate (MPA), moderate to vigorous (MVPA) and vigorous (VPA) physical activity was calculated based on PAQ-S and accelerometer data. RESULTS: The average time spent on MPA and MVPA as derived from PAQ-S and from accelerometers were significantly moderately correlated (r=0.462, P<0.001 and r=0.483, P<0.001, respectively). No significant correlation was detected between PAQ-S and accelerometer-measured time spent performing VPA (rho=0.150, P=0.057). Intraclass Correlation Coefficient (ICC) indicated a moderate agreement between PAQ-S and accelerometer in estimating MPA (ICC=0.592, P<0.001) and MVPA (ICC=0.581, P<0.001). Bland-Altman analysis revealed a small mean difference (the "bias"), between the two methods, in estimating MPA, although this difference was found to be significantly higher than zero ("bias"=27.4% of the accelerometer-measured mean score, P=0.006). On the other hand, Bland-Altman analysis revealed a large mean difference in estimating MVPA and VPA ("bias"=84.2% and 357% of the accelerometer-measured mean score for MVPA and VPA, respectively and P<0.001). The high correlation coefficient between the average and difference values between all physical activity scores derived from accelerometers and PAQ-S, indicate a systematic overestimation of physical activity time with increasing physical activity for PAQ-S. CONCLUSION: The validity of PAQ-S for the estimation of MPA and MVPA was found to be slightly similar self-reported measures for schoolchildren. Therefore, this questionnaire could be used as a tool for physical activity assessment in large population studies.

Gender influences physical activity changes during adolescence: The HELENA study.

BACKGROUND: We compared differences in physical activity (PA) between pre/mid-pubertal and post-pubertal participants according to gender. METHODS: The study included a total of 1842 healthy participants aged 12.5-17.4 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Participants wore a uniaxial accelerometer (ActiGraph© GT1M, Pensacola, FL, USA) attached to their lower back for seven consecutive days to measure PA. Pubertal status was assessed by physical examination and the population was classified as pre/mid-pubertal (Tanner stages 1-3) or post-pubertal (Tanner stages 4-5). PA was compared between these groups according to gender during the whole week, on school-free days and on school days, before and after school, and during lessons and recesses. RESULTS: When comparing the pre/mid-pubertal group with the post-pubertal group, girls' total PA did not differ between groups. However, a slight difference was observed in boys, among whom PA on school-free days showed a difference of 17.6% between the pre/mid-pubertal group and the post-pubertal group (679 kcounts vs 564 kcounts, respectively; P = 0.0007) and 20% (162 kcount vs 135 kcounts; P = 0.006) for school recess. There was no difference among girls. CONCLUSIONS: A reduced level of PA in the post-pubertal groups was only observed in boys during non-organized times such as on school-free days and during school recesses, with a moderate impact on total PA.

Inflammation profile in overweight/obese adolescents in Europe: an analysis in relation to iron status.

BACKGROUND/OBJECTIVES: The objectives of this study were to investigate the relationship between inflammatory parameters (CRP, c-reactive protein; AGP, α1-acid glycoprotein), iron status indicators (SF, serum ferritin; sTfR, soluble transferrin receptor) and body mass index (BMI) z-score, fat-free mass (FFM) and fat mass (FM) in European adolescents. Differences in intake for some nutrients (total iron, haem and non-haem iron, vitamin C, calcium, proteins) were assessed according to BMI categories, and the association of nutrient intakes with BMI z-score, FM and FFM was evaluated. METHODS: A total of 876 adolescents participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence-Cross Sectional Study were included in the study sample. RESULTS: Mean CRP values (standard error; s.e.) were significantly higher in overweight/obese adolescents (1.7±0.3 and 1.4±0.3 mg/l in boys and girls, respectively) than in thin/normal-weight adolescents (1.1±0.2 and 1.0±0.1 mg/l in boys and girls, respectively) (P<0.05). For boys, mean SF values (s.e.) were significantly higher in overweight/obese adolescents (46.9±2.7 µg/l) than in thin/normal-weight adolescents (35.7±1.7 µg/l) (P<0.001), whereas median sTfR values did not differ among BMI categories for both boys and girls. Multilevel regression analyses showed that BMI z-score and FM were significantly related to CRP and AGP (P<0.05). Dietary variables did not differ significantly among BMI categories, except for the intake of vegetable proteins, which, for boys, was higher in thin/normal-weight adolescents than in overweight/obese adolescents (P<0.05). CONCLUSIONS: The adiposity of the European adolescents was sufficient to cause chronic inflammation but not sufficient to impair iron status and cause iron deficiency.

Identification of lifestyle patterns, including sleep deprivation, associated with insulin resistance in children: the Healthy Growth Study.

BACKGROUND/OBJECTIVES: Although diet, physical activity (PA), sedentary behavior and sleep deprivation are factors that have been individually associated with insulin resistance (IR) in childhood, the combined effect of these lifestyle behaviors has not been examined yet. The current study aimed to examine the association of lifestyle patterns with IR, combining all these indices, in children. SUBJECTS/METHODS: Socio-economic, demographic, anthropometric (body weight, height and waist circumference), biochemical (plasma glucose and serum insulin), clinical (pubertal stage) and lifestyle (dietary intake, PA level and sleeping habits) data were collected from a representative sample of 2026 children (50.1% girls) aged 9-13 years in Greece. Homeostasis model assessment (HOMA-IR) was calculated, and principal component analysis was used to identify lifestyle patterns, combining all these lifestyle indices. RESULTS: In multivariable regression analyses, the lifestyle pattern characterized by more screen time, shorter sleep duration and higher consumption of sugared beverages was positively associated with HOMA-IR (ß=0.043; P=0.040), whereas the pattern characterized by more time spent on moderate-to-vigorous PA (MVPA) and more frequent eating occasions was inversely associated with HOMA-IR (ß=-0.061; P=0.003). In logistic regression analyses, children with 72.2 min/day of MVPA and 5.05 eating occasions/day and children with 141.8 min/day of MVPA and 5.22 eating occasions/day were less likely of being insulin resistant based on HOMA-IR, compared with children with 20.0 min/day of MVPA and 4.09 eating occasions/day. CONCLUSIONS: A lifestyle pattern of >72 min of MVPA and 5 eating occasions/day was associated with reduced likelihood of IR in children.

Designing and implementing a kindergarten-based, family-involved intervention to prevent obesity in early childhood: the ToyBox-study.

The development of the ToyBox-intervention was based on the outcomes of the preliminary phase of the ToyBox-study, aiming to identify young children's key behaviours and their determinants related to early childhood obesity. The ToyBox-intervention is a multi-component, kindergarten-based, family-involved intervention with a cluster-randomized design, focusing on the promotion of water consumption, healthy snacking, physical activity and the reduction/ breaking up of sedentary time in preschool children and their families. The intervention was implemented during the academic year 2012-2013 in six European countries: Belgium, Bulgaria, Germany, Greece, Poland and Spain. Standardized protocols, methods, tools and material were used in all countries for the implementation of the intervention, as well as for the process, impact, outcome evaluation and the assessment of its cost-effectiveness. A total sample of 7,056 preschool children and their parents/caregivers, stratified by socioeconomic level, provided data during baseline measurements and participated in the intervention. The results of the ToyBox-study are expected to provide a better insight on behaviours associated with early childhood obesity and their determinants and identify effective strategies for its prevention. The aim of the current paper is to describe the design of the ToyBox-intervention and present the characteristics of the study sample as assessed at baseline, prior to the implementation of the intervention.

Concepts and strategies on how to train and motivate teachers to implement a kindergarten-based, family-involved intervention to prevent obesity in early childhood. The ToyBox-study.

The key person for the implementation of kindergarten-based behavioural interventions is the kindergarten teacher. When conducting intervention studies in kindergartens, training sessions are needed to train and motivate kindergarten teachers for programme implementation. This paper presents the systematic development of the teachers' trainings executed in the ToyBox-intervention - a kindergarten-based and family-involved obesity prevention programme for children aged 4-6. Based on concepts for the education of kindergarten teachers, on general strategies for successful programme implementation and on the ToyBox programme-specific requirements, the aims of the teachers' trainings were defined and an overall concept was deduced. Regarding the concept for the ToyBox teachers' training sessions, it is concluded that the training modules should focus on presenting information on the practical implementation of the intervention. Furthermore, these modules should also include self-efficacy enhancing components and should give kindergarten teachers opportunities to share experiences. Regarding the didactic methods applied in the ToyBox teachers' training sessions, constructivist learning approaches that facilitate active participation, reflective thinking and personal involvement were implemented. Emphasis was put not only on the content but especially on the didactic methods of teachers' trainings in order to enhance devotion to, and quality and sustainability of the ToyBox-intervention.

Reliability of primary caregivers reports on lifestyle behaviours of European pre-school children: the ToyBox-study.

Reliable assessments of health-related behaviours are necessary for accurate evaluation on the efficiency of public health interventions. The aim of the current study was to examine the reliability of a self-administered primary caregivers questionnaire (PCQ) used in the ToyBox-intervention. The questionnaire consisted of six sections addressing sociodemographic and perinatal factors, water and beverages consumption, physical activity, snacking and sedentary behaviours. Parents/caregivers from six countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain) were asked to complete the questionnaire twice within a 2-week interval. A total of 93 questionnaires were collected. Test-retest reliability was assessed using intra-class correlation coefficient (ICC). Reliability of the six questionnaire sections was assessed. A stronger agreement was observed in the questions addressing sociodemographic and perinatal factors as opposed to questions addressing behaviours. Findings showed that 92% of the ToyBox PCQ had a moderate-to-excellent test-retest reliability (defined as ICC values from 0.41 to 1) and less than 8% poor test-retest reliability (ICC < 0.40). Out of the total ICC values, 67% showed good-to-excellent reliability (ICC from 0.61 to 1). We conclude that the PCQ is a reliable tool to assess sociodemographic characteristics, perinatal factors and lifestyle behaviours of pre-school children and their families participating in the ToyBox-intervention.

Process evaluation design and tools used in a kindergarten-based, family-involved intervention to prevent obesity in early childhood. The ToyBox-study.

Process evaluation (PE) is used for the in-depth evaluation of the implementation process of health promotion programmes. The aim of the current paper was to present the PE design and tools used in the ToyBox-intervention. The PE design was based on a three-step approach, including the identification of ToyBox-specific PE elements (step 1), the development of PE tools and harmonization of procedures (step 2), and the implementation of PE using standardized protocol and tools across the intervention countries (step 3). Specifically, to evaluate the implementation of the intervention, teachers' monthly logbooks were recorded (dose delivered, fidelity, dose received); post-intervention questionnaires were completed by parents/caregivers and teachers (dose received); participation and attrition rates were recorded (recruitment, reach); and audit questionnaires and retrospective information on weather conditions were collected (physical and social environment within which the intervention was implemented). Regarding the teachers' training sessions, the researchers who performed the trainings completed evaluation forms and documented teachers' attendance after each training (dose delivered, fidelity, dose received) and teachers completed evaluation forms after each training (dose received). The PE performed in the ToyBox-intervention may contribute in the evaluation of its effectiveness, guide the revision of the intervention material and provide insights for future health promotion programmes and public health policy.

Tools, harmonization and standardization procedures of the impact and outcome evaluation indices obtained during a kindergarten-based, family-involved intervention to prevent obesity in early childhood: the ToyBox-study.

The ToyBox-intervention is a kindergarten-based, family-involved intervention targeting multiple lifestyle behaviours in preschool children, their teachers and their families. This intervention was conducted in six European countries, namely Belgium, Bulgaria, Germany, Greece, Poland and Spain. The aim of this paper is to provide a descriptive overview of the harmonization and standardization procedures of the baseline and follow-up evaluation of the study (and substudies). Steps related to the study's operational, standardization and harmonization procedures as well as the impact and outcome evaluation assessment tools used are presented. Experiences from the project highlight the importance of safeguarding the measurement process to minimize data heterogeneity derived from potential measurement error and country-by-country differences. In addition, it was made clear that continuing quality control and support is an important component of such studies. For this reason, well-supported communication channels, such as regular email updates and teleconferences, and regular internal and external meetings to ensure smooth and accurate implementation were in place during the study. The ToyBox-intervention and its harmonized and standardized procedures can serve as a successful case study for future studies evaluating the efficacy of similar interventions.

Reliability of anthropometric measurements in European preschool children: the ToyBox-study.

The ToyBox-study aims to develop and test an innovative and evidence-based obesity prevention programme for preschoolers in six European countries: Belgium, Bulgaria, Germany, Greece, Poland and Spain. In multicentre studies, anthropometric measurements using standardized procedures that minimize errors in the data collection are essential to maximize reliability of measurements. The aim of this paper is to describe the standardization process and reliability (intra- and inter-observer) of height, weight and waist circumference (WC) measurements in preschoolers. All technical procedures and devices were standardized and centralized training was given to the fieldworkers. At least seven children per country participated in the intra- and inter-observer reliability testing. Intra-observer technical error ranged from 0.00 to 0.03 kg for weight and from 0.07 to 0.20 cm for height, with the overall reliability being above 99%. A second training was organized for WC due to low reliability observed in the first training. Intra-observer technical error for WC ranged from 0.12 to 0.71 cm during the first training and from 0.05 to 1.11 cm during the second training, and reliability above 92% was achieved. Epidemiological surveys need standardized procedures and training of researchers to reduce measurement error. In the ToyBox-study, very good intra- and-inter-observer agreement was achieved for all anthropometric measurements performed.

Developing the intervention material to increase physical activity levels of European preschool children: the ToyBox-study.

Early childhood is an important period for adopting positive health-related behaviours. More than 95% of European preschool children attend kindergartens, making these settings ideal for the implementation of health promotion interventions. The ToyBox-intervention addressed preschool children, their parents/caregivers and teachers. The aim of the intervention was to improve four energy balance-related behaviours (i.e. healthy snacking, water consumption, physical activity and sedentary behaviour) by implementing a kindergarten-based, family-involved intervention in six European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain). The intervention material was developed following the intervention mapping protocol, taking into account local and cultural differences among the intervention countries. The present paper focuses on the development of the physical activity component of the intervention. Parental involvement was addressed by providing parents/caregivers with two newsletters, two tip cards and a poster. Teachers received a handbook with guidance on environmental changes in the classroom, 26 physical education sessions and suggestions for fun, interactive classroom activities aiming at total class participation to increase preschoolers' physical activity levels. The ToyBox-intervention material was distributed according to a standard time frame. Teachers received their material prior to the start of the intervention and parents/caregivers received their material during the intervention when each energy balance-related behaviour was implemented.

Designing and implementing teachers' training sessions in a kindergarten-based, family-involved intervention to prevent obesity in early childhood. The ToyBox-study.

Since school-based interventions are mainly delivered by the school staff, they need to be well-trained and familiarized with the programme's aims, procedures and tools. Therefore, the institute, research group, governmental or non-governmental body in charge of the coordination and implementation of the programme needs to devote time and resources to train the school staff before programme's implementation. This is particularly crucial in multi-centre studies where more than one research teams are involved. Both research teams and school staff need to be trained, using standard protocols and procedures, to ensure that the intervention will be delivered in a standardized manner throughout the intervention centres. The ToyBox-intervention, a multi-component, kindergarten-based, family-involved intervention, focusing on water consumption, snacking, physical activity and sedentary behaviours in preschool children, was implemented over the academic year 2012-2013 in six European countries. As part of this intervention, three teachers' training sessions were delivered to motivate and train teachers in implementing the intervention. The local researchers were trained centrally before delivering the training sessions for the teachers and followed a common protocol using standardized presentations and procedures. The aim of the current paper is to describe the protocol and methodological issues related to the teachers' training sessions conducted within the ToyBox-intervention.