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Background: In view of the high burden of childhood overweight/obesity (OW/OB), it is important to identify targets for interventions that may have the greatest effects on preventing OW/OB in early life. Using methods of causal inference, we studied the effects of sustained behavioral interventions on the long-term risk of developing OW/OB based on a large European cohort. Methods: Our sample comprised 10 877 children aged 2 to < 10 years at baseline who participated in the well-phenotyped IDEFICS/I.Family cohort. Children were followed from 2007/08 to 2020/21. Applying the parametric g-formula, the 13-year risk of developing OW/OB was estimated under various sustained hypothetical interventions on physical activity, screen time, dietary intake and sleep duration. Interventions imposing adherence to recommendations (e.g. maximum 2 h/day screen time) as well as interventions 'shifting' the behavior by a specified amount (e.g. decreasing screen time by 30 min/day) were compared to 'no intervention' (i.e. maintaining the usual or so-called natural behavior). Separately, the effectiveness of these interventions in vulnerable groups was assessed. Results: The 13-year risk of developing OW/OB was 30.7% under no intervention and 25.4% when multiple interventions were imposed jointly. Meeting screen time and moderate-to-vigorous physical activity (MVPA) recommendations were found to be most effective, reducing the incidence of OW/OB by -2.2 [-4.4;-0.7] and -2.1 [-3.7;-0.8] percentage points (risk difference [95% confidence interval]), respectively. Meeting sleep recommendations (-0.6 [-1.1;-0.3]) had a similar effect as increasing sleep duration by 30 min/day (-0.6 [-0.9;-0.3]). The most effective intervention in children of parents with low/medium educational level was being member in a sports club; for children of mothers with OW/OB, meeting screen time recommendations and membership in a sports club had the largest effects. Conclusions: While the effects of single behavioral interventions sustained over 13 years were rather small, a joint intervention on multiple behaviors resulted in a relative reduction of the 13-year OW/OB risk by between 10 to 26%. Individually, meeting MVPA and screen time recommendations were most effective. Nevertheless, even under the joint intervention the absolute OW/OB risk remained at a high level of 25.4% suggesting that further strategies to better prevent OW/OB are required. [ABSTRACT FROM AUTHOR]

Introduction One of the major research dimensions of the Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study involved the development, implementation and evaluation of a setting-based community-oriented intervention programme for primary prevention of childhood obesity. In this supplement of Obesity Reviews, a compilation of key results of the IDEFICS intervention is packaged in a series of complementary papers. Objective This paper describes the overall design and methods of the IDEFICS intervention in order to facilitate a comprehensive reading of the supplement. In addition, some 'best practice' examples are described. Results The IDEFICS intervention trial was conducted to assess whether the IDEFICS intervention prevented obesity in young children aged 2 to 9.9 years. The study was a non-randomized, quasi-experimental trial with one intervention matched to one control region in each of eight participating countries. The intervention was designed following the intervention mapping framework, using a socio-ecological theoretical approach. The intervention was designed to address several key obesity-related behaviours in children, parents, schools and community actors; the primary outcome was the prevalence of overweight/obesity according to the IOTF criteria based on body mass index. The aim was to achieve a reduction of overweight/obesity prevalence in the intervention regions. The intervention was delivered in school and community settings over a 2-year period. Data were collected in the intervention and control cohort regions at baseline and 2 years later. Conclusion This paper offers an introductory framework for a comprehensive reading of this supplement on IDEFICS intervention key results. [ABSTRACT FROM AUTHOR]

Objective The objective of this paper is to evaluate the behavioural effects, as reported by the parents of the participating boys and girls, of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) intervention. Methods The effectiveness of the IDEFICS intervention was evaluated through a cluster-controlled trial in eight European countries (control and intervention communities in each country) including more than 16,000 children. The 2- to 9.9-year-old children in the intervention group were exposed to a culturally adapted intervention that aimed to prevent childhood obesity through the community, schools/kindergartens and family. Parents completed questionnaires to measure water, soft drink and fruit juice intake; fruit and vegetable intake; daily TV viewing and other sedentary behaviours; daily physical activity levels and strengthening of the parent-child relationships at baseline and follow-up (2 years later). Mixed models with an additional random effect for country were used to account for the clustered study design, and results were stratified by sex. Results The pan-European analysis revealed no significant time by condition interaction effects, neither for boys nor girls, i.e. the analysis revealed no intervention effects on the behaviours of the IDEFICS children as reported by their parents ( F = 0.0 to 3.3, all p > 0.05). Also very few significances were found in the country-specific analyses. Positive intervention effects were only found for sport club participation in Swedish boys, for screen time in weekends for Spanish boys and for TV viewing in Belgian girls. Conclusion Although no expected intervention effects as reported by the parents on diet, physical activity and sedentary behaviours could be shown for the overall IDEFICS cohort, a few favourable intervention effects were found on specific behaviours in some individual countries. More in-depth analyses of the process evaluation data are needed to obtain more insight into the relationship between the level of exposure to the intervention and its effect. © 2015 World Obesity [ABSTRACT FROM AUTHOR]

Background/Objectives Childhood obesity is a major public health concern but evidence-based approaches to tackle this epidemic sustainably are still lacking. The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study investigated the aetiology of childhood obesity and developed a primary prevention programme. Here, we report on the effects of the IDEFICS intervention on indicators of body fatness. Subjects/Methods The intervention modules addressed the community, school and parental level, focusing on diet, physical activity and stress-related lifestyle factors. A cohort of 16,228 children aged 2-9.9 years - about 2000 per country - was equally divided over intervention and control regions. (Participating countries were Sweden, Germany, Estonia, Hungary, Cyprus, Italy, Spain and Belgium.) We compared the prevalence of overweight/obesity and mean values of body mass index z-score, per cent body fat and waist-to-height ratio over 2 years of follow-up. Mixed models adjusting for age and socioeconomic status of the parents and with an additional random effect for country accounted for the clustered study design. Results The prevalence of overweight and obesity increased in both the intervention and control group from 18.0% at baseline to 22.9% at follow-up in the control group and from 19.0% to 23.6% in the intervention group. The difference in changes between control and intervention was not statistically significant. For the cohort as a whole, the changes in indicators of body fatness did not show any clinically relevant differences between the intervention and control groups. Changes in favour of intervention treatment in some indicators were counterbalanced by changes in favour of the control group in some other indicators. Conclusions Over the 2-year-observation period, the IDEFICS primary prevention programme for childhood obesity has not been successful in reducing the prevalence of overweight and obesity nor in improving indicators of body fatness in the target population as a whole. [ABSTRACT FROM AUTHOR]

Objectives The first aim was to describe the intervention implementation and reception with specific regard to physical activity (PA) within Belgian schools participating in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) intervention. Second, we examined if a higher intervention process score in schools showed more favourable effects on children's objectively measured PA and sedentary time (ST). Methods The IDEFICS intervention focused on improving children's health behaviour (including PA) at the community, school/kindergarten and family level. Five process evaluation questionnaires completed by school working groups, and (physical education) teachers were used for the process evaluation of four intervention modules (school working groups, healthy weeks, school environment, health-related physical education and PA). Items were summed to calculate a total intervention process score per school. Schools were subdivided into three groups (low, medium and high score). Multilevel models were used to examine if changes in PA or ST differed between schools with a low, medium or high score. In total, 333 children (54.1% girls, mean age 6.0 ± 1.5 years) from 34 intervention schools (18 pre-schools and 16 primary schools) in the town of Geraardsbergen, Belgium, provided valid accelerometer data for two weekdays and one weekend day. Results Mean intervention process score (maximum value = 44) was 20.9 ± 5.8 for schools. The breakdown per module showed which components were implemented and received well and which components could have been improved. After the intervention, the decrease in light PA and increase in ST was much higher in children from primary schools with a low intervention process score, whereas the behaviours remained relatively stable in children from primary schools with a medium or high score. The change in moderate to vigorous PA did not differ significantly between schools with a low, medium or high score. Conclusion The IDEFICS intervention was relatively able to prevent unfavourable changes in ST and light PA in schools with a medium and high intervention process score. Further process evaluation research is needed to obtain a more profound picture of the IDEFICS intervention process. [ABSTRACT FROM AUTHOR]

Background The aim of this study was to explore whether the IDEFICS intervention had a differential effect on 11,041 children's weight trajectories depending on their baseline body mass index status. Methods Two subgroups of children are considered in the present analysis: those who were overweight or obese prior to the intervention and those who were neither overweight nor obese. Results Among children in all eight countries who did not have prevalent overweight or obesity (OWOB) at baseline, 2 years later, there was no significant difference between intervention and control groups in risk of having developed OWOB. However, we observed a strong regional heterogeneity, which could be attributed to the presence of one distinctly outlying country, Belgium, where the intervention group had increased risk for becoming overweight. In contrast, among the sample of children with prevalent OWOB at baseline, we observed a significantly greater probability of normalized weight status after 2 years. In other words, a protective effect against persistent OWOB was observed in children in intervention regions compared with controls, which corresponded to an adjusted odds ratio of 0.76 (95% confidence interval: 0.58, 0.98). Discussion This analysis thus provided evidence of a differential effect of the IDEFICS intervention, in which children with overweight may have benefited without having been specifically targeted. However, no overall primary preventive effect could be observed in children without initial overweight or obesity. [ABSTRACT FROM AUTHOR]

Background According to recent findings, short sleep duration is associated with overweight in children. However, primary prevention efforts aimed at achieving adequate sleep among children are scarce. Therefore, the 'Identification and prevention of Dietary-induced and lifestyle-induced health EFfects In Children and infantS' (IDEFICS) study implemented a multilevel intervention that included sleep duration as a key behavioural target. The aim of this study is to evaluate sleep duration among children participating in the IDEFICS study. Methods The IDEFICS nocturnal sleep intervention was included as part of stress reduction educational messages aimed at parents and children. Sleep was assessed by a parental 24-h recall (only weekdays; n = 8,543) and by a diary (weekdays and weekends separately; n = 4,150). Mixed linear models tested the intervention effect on sleep duration change between baseline when children were 2-9.9 years of age (2007/2008) and follow-up (2009/2010). Logistic mix models were used to study the intervention effect on the presence of TV in the children's bedroom (one of the intervention messages; n = 8,668). Additionally, parents provided qualitative data regarding exposure to the intervention. Results About 51.1% of the parents in the intervention regions reported awareness of the sleep intervention. A small intervention effect was seen on weeknight sleep duration in that the decrease in sleep duration over 2 years was smaller in the intervention (15 min) as compared with control regions (19 min) ( p = 0.044). There was no overall intervention effect on weekend sleep duration or on the presence of a TV in the bedroom. A small significant time effect between baseline and follow-up was found on bedroom TV presence depending on self-reported intervention exposure (3% increase in TV presence in exposed versus 6.6% increase in non-exposed). Children without a TV in the bedroom had longer nocturnal sleep duration. Discussion The sleep component of the intervention did not lead to clinically relevant changes in sleep duration. Future interventions aimed at young children's sleep duration could benefit from more specific and intense messaging than that found in the IDEFICS intervention. Future research should use objective measures of sleep duration as well as intermediate outcomes (sleep knowledge, sleep environment and sleep practices). [ABSTRACT FROM AUTHOR]

Background The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study investigated the aetiology of childhood obesity and developed a primary prevention programme. Methods Pre-intervention adherence to key behaviours related to childhood obesity, namely water/sweetened drink, fruit/vegetable consumption, daily TV time, physical activity, family time and adequate sleep duration, was measured at baseline. Adherence to international recommendations was converted into a composite score ranging from 0 (none) to 6 (adhering to all). Data on adherence were available for 7,444 to 15,084 children aged 2-9.9 years, depending on the behaviour. By means of multi-level logistic regression models adjusted for age, sex and country, we calculated odds ratios (OR) and 95% confidence intervals (CI) to estimate the relationship between adherence to these recommendations and the risk of being overweight/obese. Results Adherence ranged from 15.0% (physical activity) to 51.9% (TV time). As adherence increased, a lower chance of being overweight/obese was observed; adhering to only one key behaviour (score = 1) meant an OR = 0.81 (CI: 0.65-1.01) compared with non-adherence (score = 0), while adhering to more than half of the key behaviours (score ≥ 4) halved the chance for overweight/obesity (OR = 0.54, CI: 0.37-0.80). Adherence to physical activity, TV and sleep recommendations was the main driver reducing the chance of being overweight. Overweight/obese children were more likely not to adhere to at least one of the recommended behaviours (19.8%) than normal-weight/thin children (12.9%) Conclusion The selected key behaviours do not contribute equally to a reduced chance of being overweight. Future interventions may benefit most from moving more, reducing TV time and getting adequate sleep. © 2015 World Obesity [ABSTRACT FROM AUTHOR]

Background This paper reports on the effectiveness of the prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) intervention on objectively measured physical activity (PA) and sedentary time (ST) in 2- to 9.9-year-old European boys and girls. Methods The intervention was evaluated after 2 years through a non-randomized cluster-controlled trial in eight European countries (one control and one intervention community per country). All children in the intervention group received a culturally adapted childhood obesity prevention programme through the community, schools/kindergartens and family. A random sub-sample of children participating in the IDEFICS study wore an accelerometer at baseline and follow-up for at least 3 days ( n = 9,184). Of this sample, 81% provided valid accelerometer data at baseline ( n = 7,413; 51% boys; 6.21 ± 1.76 years; boys: 617 ± 170 cpm day−1; girls 556 ± 156 cpm day−1) and 3,010 children provided valid accelerometer data at baseline and during the follow-up survey 2 years later. Results In boys and girls, no significant differences in PA and ST were found between intervention and control groups over 2 years. Strong temporal effects were found in the total sample of boys and girls: the percentage of time spent in light PA per day decreased by 4 percentage points in both boys and girls between baseline and follow-up (both: p < 0.001), while time spent in ST per day increased by 4 percentage points in both sexes over time (both: p < 0.001). Percentage of time spent in moderate-to-vigorous PA per day remained stable over time in boys and girls. Conclusion Despite the socio-ecological approach and implementation of a culturally adapted intervention in each country, no effects of the IDEFICS intervention were found on children's objectively measured PA and ST. Behavioural interventions for children may need to enhance specificity and intensity at the family level using other behaviour change techniques and more direct strategies to reach parents. © 2015 World Obesity [ABSTRACT FROM AUTHOR]

Objectives The primary aim of the present study was to obtain insight into parents' perception of the IDEFICS intervention at the school or preschool/kindergarten and community levels and whether they received specific materials related to the intervention. The secondary aim was to analyse whether parents who reported higher levels of exposure to the IDEFICS intervention had children with more favourable changes in body mass index (BMI) z-scores between baseline and after 2 years of intervention. Methods Process evaluation of the IDEFICS intervention investigated the implementation of the 2-year intervention in the intervention communities. Intervention group parents ( n = 4,180) in seven countries (Belgium, Cyprus, Estonia, Germany, Italy, Spain and Sweden) answered questions about their exposure to the IDEFICS study. To analyse the relationship between exposure and BMI z-score, a composite score was calculated for exposure at the setting and at the community levels. Results The frequency of parental exposure to the IDEFICS messages not only through the community but also through the (pre)school/kindergarten was lower than what was intended and planned. The dose received by the parents was considerably higher through the (pre)school/kindergarten settings than that through the community in all countries. Efforts by the settings or communities related to fruit and vegetable consumption (range 69% to 97%), physical activity promotion (range 67% to 91%) and drinking water (range 49% to 93%) were more visible and also realized more parental involvement than those related to TV viewing, sleep duration and spending time with the family (below 50%). Results showed no relation of parental exposure at the setting or the community level on more favourable changes in children's BMI z-scores for the total sample. Country-specific analyses for parental exposure at the setting level showed an expected positive effect in German girls and an unexpected negative effect in Italian boys. Conclusion Parental exposure and involvement in the IDEFICS intervention in all countries was much less than aimed for, which might be due to the diverse focus (six key messages) and high intensity and duration of the intervention. It may also be that the human resources invested in the implementation and maintenance of intervention activities by the study centres, the caretakers and the community stakeholders were not sufficient. Higher levels of parental exposure were not related to more favourable changes in BMI z-scores. © 2015 World Obesity [ABSTRACT FROM AUTHOR]

Background:Dietary patterns, physical activity (PA) and sedentary behaviours are some of the main behavioural determinants of obesity; their combined influence in children has been addressed in a limited number of studies.Subjects/Methods:Children (16 228) aged 2-9 years old from eight European countries participated in the baseline survey of the IDEFICS study. A subsample of 11 674 children (50.8% males) were included in the present study. Children's food and beverage consumption (fruit and vegetables (F&V) and sugar-sweetened beverages (SSBs)), PA and sedentary behaviours were assessed via parental questionnaires. Sex-specific cluster analysis was applied to identify behavioural clusters. Analysis of covariance and logistic regression were applied to examine the association between behavioural clusters and body composition indicators (BCIs).Results:Six behavioural clusters were identified (C1-C6) both in boys and girls. In both sexes, clusters characterised by high level of PA (C1 and C3) included a large proportion of older children, whereas clusters characterised by low SSB consumption (C5 and C6) included a large proportion of younger children. Significant associations between derived clusters and BCI were observed only in boys; those boys in the cluster with the highest time spent in sedentary activities and low PA had increased odds of having a body mass index z-score (odds ratio (OR)=1.33; 95% confidence interval (CI)=(1.01, 1.74)) and a waist circumference z-score (OR=1.41; 95%CI=(1.06, 1.86)) greater than one.Conclusion:Clusters characterised by high sedentary behaviour, low F&V and SSB consumption and low PA turned out to be the most obesogenic factors in this sample of European children. [ABSTRACT FROM AUTHOR]

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Background:Despite documented benefits of a Mediterranean-like dietary pattern, there is a lack of knowledge about how children from different European countries compare with each other in relation to the adherence to this pattern. In response to this need, we calculated the Mediterranean diet score (MDS) in 2-9-year-old children from the Identification and prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) eight-country study.Subjects and methods:Using 24 h dietary recall data obtained during the IDEFICS study (n=7940), an MDS score was calculated based on the age- and sex-specific population median intakes of six food groups (vegetables and legumes, fruit and nuts, cereal grains and potatoes, meat products and dairy products) and the ratio of unsaturated to saturated fats. For fish and seafood, which was consumed by 10% of the population, one point was given to consumers. The percentages of children with high MDS levels (>3) were calculated and stratified by sex, age and by having at least one migrant parent or both native parents. Demographic (sex and age) and socioeconomic characteristics (parental education and income) of children showing high (>3) vs low (⩽3) MDS levels were examined.Results:The highest prevalence of children with MDS >3 was found among the Italian pre-school boys (55.9%) and the lowest among the Spanish school-aged girls (26.0%). Higher adherence to a Mediterranean-like dietary pattern was not associated with living in a Mediterranean country or in a highly educated or high-income family, although with some exceptions. Differences in adherence between boys and girls or age groups varied between countries without any general pattern.Conclusions:With the exception of Italian pre-schoolers, similar adherence levels to a Mediterranean-like dietary pattern have been observed among European children. [ABSTRACT FROM AUTHOR]

Objective:To estimate the prevalence of the metabolic syndrome (MetS) using reference standards obtained in European children and to develop a quantitative MetS score and describe its distribution in children.Design and methods:Population-based survey in eight European countries, including 18745 children 2.0 to 10.9 years, recruited during a second survey. Anthropometry (weight, height and waist circumference), blood pressure and serum-fasting triglycerides, HDL cholesterol, glucose and insulin were measured. We applied three widely accepted definitions of the pediatric MetS and we suggest a new definition, to guide pediatricians in decisions about close monitoring or even intervention (values of at least three of the MetS components exceeding the 90th or 95th percentile, respectively). We used a z-score standardisation to calculate a continuous score combining the MetS components.Results:Among the various definitions of MetS, the highest prevalence (5.5%) was obtained with our new definition requiring close observation (monitoring level). Our more conservative definition, requiring pediatric intervention gives a prevalence of 1.8%. In general, prevalences were higher in girls than in boys. The prevalence of metabolic syndrome is highest among obese children. All definitions classify a small percentage of thin or normal weight children as being affected. The metabolic syndrome score shows a positive trend with age, particularly regarding the upper percentiles of the score.Conclusions:According to different definitions of pediatric MetS, a non-negligible proportion of mostly prepubertal children are classified as affected. We propose a new definition of MetS that should improve clinical guidance. The continuous score developed may also serve as a useful tool in pediatric obesity research. It has to be noted, however, that the proposed cutoffs are based on a statistical definition that does not yet allow to quantify the risk of subsequent disease. [ABSTRACT FROM AUTHOR]

Background:There is a lack of common surveillance systems providing comparable figures and temporal trends of the prevalence of overweight (OW), obesity and related risk factors among European preschool and school children. Comparability of available data is limited in terms of sampling design, methodological approaches and quality assurance. The IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study provides one of the largest European data sets of young children based on state-of-the-art methodology.Objective:To assess the European distribution of weight status according to different classification systems based on body mass index (BMI) in children (2.0-9.9 years). To describe the prevalence of weight categories by region, sex, age and socioeconomic position.Design:Between 2007 and 2010, 18 745 children from eight European countries participated in an extensive, highly standardised protocol including, among other measures, anthropometric examinations and parental reports on socio-demographic characteristics.Results:The combined prevalence of OW/obesity ranges from more than 40% in southern Europe to less than 10% in northern Europe. Overall, the prevalence of OW was higher in girls (21.1%) as compared with boys (18.6%). The prevalence of OW shows a negative gradient with social position, with some variation of the strength and consistency of this association across Europe. Overall, population groups with low income and/or lower education levels show the highest prevalence of obesity. The use of different reference systems to classify OW results in substantial differences in prevalence estimates and can even reverse the reported difference between boys and girls.Conclusions:There is a higher prevalence of obesity in populations from southern Europe and in population groups with lower education and income levels. Our data confirm the need to develop and reinforce European public health policies to prevent early obesity and to reduce these health inequalities and regional disparities. [ABSTRACT FROM AUTHOR]

Introduction:To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references.Objectives:The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS).Methods:Overall 18 745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N=5915) were excluded from the analysis. Anthropometric measurements (BMI (N=12 830); triceps, subscapular, fat mass and fat mass index (N=11 845-11 901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N=8129-8205), neck circumference (N=12 241); waist circumference and waist-to-height ratio (N=12 381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS.Results:Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age- and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5- to <5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years.Conclusion:The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children. [ABSTRACT FROM AUTHOR]

Objective:To establish age- and sex-specific reference values for serum leptin and adiponectin in normal-weight 3.0-8.9-year old European children.Subjects and methods:Blood samples for hormone analysis were taken from 1338 children of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study cohort. Only normal-weight children aged 3.0-8.9 years were included (n=539) in our analysis. Using the General Additive Model for Location Scale and Shape, age- and sex-specific percentiles were derived. The influence of under/overweight and obesity on the proposed reference curves based on normal-weight children was investigated in several sensitivity analyses using the sample without obese children (n=1015) and the whole study sample (n=1338).Results:There was a negative age trend of adiponectin blood levels and a positive trend of leptin levels in boys and girls. Percentiles derived for girls were generally higher than those obtained for boys. The corresponding age-specific differences of the 97th percentile ranged from −2.2 to 4.6 μg ml−1 and from 2.2 to 4.8 ng ml−1 for adiponectin and leptin, respectively.Conclusions:According to our knowledge, these are the first reference values of leptin and adiponectin in prepubertal, normal-weight children. The presented adiponectin and leptin reference curves may allow for a more differentiated interpretation of children's hormone levels in epidemiological and clinical studies. [ABSTRACT FROM AUTHOR]

Background/Objective:Quantitative ultrasound measurements and bone metabolic markers can help to monitor bone health and to detect impaired skeletal development. Population-based reference values for children may serve as a basis for preventive measures to reduce the risk of osteoporosis and osteoporotic fractures in later life. This is the first paper providing age-, sex- and height-specific reference values for bone stiffness index (SI) and serum carboxy-terminal cross-linking telopeptide of type I collagen (CTX) in healthy, apparently prepubertal children.Subjects/Methods:In the population-based IDEFICS baseline survey (2007-2008) and follow-up (2009-2010), 18 745 children from eight European countries were newly recruited. A total of 10 791 2-10.9-year-old and 1646 3-8.9-year-old healthy children provided data on SI of the right and left calcaneus and serum CTX, respectively. Furthermore, height and weight were measured. Percentile curves were calculated using the General Additive Model for Location Scale and Shape (GAMLSS) to model the distribution of SI and CTX depending on multiple covariates while accounting for dispersion, skewness, and the kurtosis of this distribution.Results:SI was negatively associated with age and height in children aged 2-5 years, whereas a positive association was observed in children aged 6-10 years. The dip in SI occurred at older age for higher SI percentiles and was observed earlier in taller children than in smaller children. The CTX reference curves showed a linear-positive association with age and height. No major sex differences were observed for the SI and CTX reference values.Conclusion:These reference data lay the ground to evaluate bone growth and metabolism in prepubertal children in epidemiological and clinical settings. They may also inform clinical practice to monitor skeletal development and to assess adverse drug reactions during medical treatments. [ABSTRACT FROM AUTHOR]

Background/objectives:To address behaviours associated with childhood obesity, certain target values are recommended that should be met to improve children's health. In the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study such lifestyle recommendations were conveyed as six key messages. Here, we investigate the adherence of European children to these messages.Methods:The IDEFICS intervention was based on the intervention mapping approach with the following six targets: increase water consumption (to replace sugar-containing beverages), increase fruit/vegetable consumption, reduce daily screen time, increase daily physical activity, improve the quality of family life and ensure adequate sleep duration. Internationally recommended target values were applied to determine the prevalence of children meeting these targets.Results:In a cohort of 18 745 children participating in the IDEFICS baseline survey or newly recruited during follow-up, data on the above lifestyle behaviours were collected for a varying number of 8302 to 17 212 children. Information on all six behaviours was available for 5140 children. Although 52.5% of the cohort was classified in the highest category of water consumption, only 8.8% met the target of an intake of fruits/vegetables five times a day. The prevalence of children adhering to the recommendation regarding total screen time-below 1 h for pre-school children and 2 h for school children-was 51.1%. The recommended amount of at least 60 min of moderate-to-vigorous physical activity per day was fulfilled by 15.2%. Family life of the child measured by various indicators was considered as satisfactory in 22.8%. Nocturnal sleep duration of 11 (10) hours or more in pre-school (school) children was achieved by 37.9%. In general, children in northern countries and younger children showed better adherence to the recommendations. Only 1.1% of the children adhered to at least five of these recommendations.Conclusions:Current adherence of children to lifestyle recommendations to prevent childhood obesity is low where observed differences with respect to country, age and gender call for targeted intervention. [ABSTRACT FROM AUTHOR]

Objectives:To describe energy density (ED; kcal g−1) of dietary intake of European children.Methods:From 16 228 children who participated in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) baseline examination, 8551 children with 24-h dietary recalls (24-HDR), with plausible reported energy intakes and complete covariate information were included in the present analysis. ED was calculated using two methods: (1) ED including solid foods (EDF) and (2) ED including solid foods and energy-containing beverages (EDF&B). Beverage energy was calculated in kcal per day. Dietary characteristics and body mass index (BMI) z-score of children aged 2 to <6 years and 6 to <10 years were compared between children with an overall EDF below the <25th percentile, between the 25th and 75th percentile as well as above the >75th percentile. Standardised regression coefficients were estimated to assess the association between dietary characteristics, BMI z-score and ED of the diet.Results:Children with low EDF and EDF&B diets consumed less energy but higher quantity of food and beverages than children with high EDF and EDF&B diets. Consumption of caloric beverages decreased with increasing EDF&B of the diet owing to the relatively low ED of the beverages, in relation to solid foods. Generally, children with low EDF and EDF&B diets showed healthier food choices than peers with higher EDF and EDF&B diets. In this sample, EDF and EDF&B were not associated with BMI z-score.Conclusion:Health promotion strategies should proclaim lower ED diets by means of foods with high water and low fat content and mainly fruit and vegetable components. Excluding caloric beverages from EDF calculation is a useful method to avoid misinterpretation of true exposure to a high energy dense diet. We recommend excluding caloric beverages from EDF calculation when investigating the effect of ED on a certain (health) outcome. [ABSTRACT FROM AUTHOR]

Objective:Valid estimates of population intakes are essential for monitoring trends as well as for nutritional interventions, but such data are rare in young children. In particular, the problem of misreporting in dietary data is usually not accounted for. Therefore, this study aims to provide accurate estimates of intake distributions in European children.Design:Cross-sectional setting-based multi-centre study.Subjects:A total of 9560 children aged 2-9 years from eight European countries with at least one 24-h dietary recall (24-HDR).Methods:The 24-HDRs were classified in three reporting groups based on age- and sex-specific Goldberg cutoffs (underreports, plausible reports, overreports). Only plausible reports were considered in the final analysis (N=8611 children). The National Cancer Institute (NCI)-Method was applied to estimate population distributions of usual intakes correcting for the variance inflation in short-term dietary data.Results:The prevalence of underreporting (9.5%) was higher compared with overreporting (3.4%). Exclusion of misreports resulted in a shift of the energy and absolute macronutrient intake distributions to the right, and further led to the exclusion of extreme values, that is, mean values and lower percentiles increased, whereas upper percentiles decreased. The distributions of relative macronutrient intakes (% energy intake from fat/carbohydrates/proteins) remained almost unchanged when excluding misreports. Application of the NCI-Method resulted in markedly narrower intake distributions compared with estimates based on single 24-HDRs. Mean percentages of usual energy intake from fat, carbohydrates and proteins were 32.2, 52.1 and 15.7%, respectively, suggesting the majority of European children are complying with common macronutrient intake recommendations. In contrast, total water intake (mean: 1216.7 ml per day) lay below the recommended value for >90% of the children.Conclusion:This study provides recent estimates of intake distributions of European children correcting for misreporting as well as for the daily variation in dietary data. These data may help to assess the adequacy of young children's diets in Europe. [ABSTRACT FROM AUTHOR]

BACKGROUND/OBJECTIVES:Individual lifestyle behaviours have independently been associated with cardiovascular diseases (CVD) risk factors in children. This study aimed to identify clustered lifestyle behaviours (dietary, physical activity (PA) and sedentary indicators) and to examine their association with CVD risk factors in children aged 2-9 years.SUBJECTS/METHODS:Participants included 4619 children (51.6% boys) from eight European countries participating in the IDEFICS cross-sectional baseline survey (2007-2008). Insulin resistance, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, sum of two skinfolds and systolic blood pressure (SBP) z-scores were summed to compute a CVD risk score. Cluster analyses stratified by sex and age groups (2 to <6 years; 6-9 years) were performed using parental-reported data on fruit, vegetables and sugar-sweetened beverages (SSB) consumption, PA performance and television video/DVD viewing.RESULTS:Five clusters were identified. Associations between CVD risk factors and score, and clusters were obtained by multiple linear regression using cluster 5 ('low beverages consumption and low sedentary') as the reference cluster. SBP was positively associated with clusters 1 ('physically active'; β=1.34; 95% confidence interval (CI): 0.02, 2.67), 2 ('sedentary'; β=1.84; 95% CI: 0.57, 3.11), 3 ('physically active and sedentary'; β=1.45; 95% CI: 0.15, 2.75) and 4 ('healthy diet'; β=1.83; 95% CI: 0.50, 3.17) in older boys. A positive association was observed between CVD risk score and clusters 2 (β=0.60; 95% CI: 0.20, 1.01), 3 (β=0.55; 95% CI: 0.14, 0.97) and 4 (β=0.60, 95% CI: 0.18, 1.02) in older boys.CONCLUSIONS:Low television/video/DVD viewing levels and low SSB consumption may result in a healthier CVD profile rather than having a diet rich in fruits and vegetables or being physically active in (pre-)school children. [ABSTRACT FROM AUTHOR]

Dietary assessment is strongly affected by misreporting (both under- and over-reporting), which results in measurement error. Knowledge about misreporting is essential to correctly interpret potentially biased associations between diet and health outcomes. In young children, dietary data mainly rely on proxy respondents but little is known about determinants of misreporting here. The present analysis was conducted within the framework of the multi-centre IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study and is based on 6101 children aged 2–9 years with 24 h dietary recall (24-HDR) and complete covariate information. Adapted Goldberg cut-offs were applied to classify the 24-HDR as ‘over-report’, ‘plausible report’ or ‘under-report’. Backward elimination in the course of multi-level logistic regression analyses was conducted to identify factors significantly related to under- and over-reporting. Next to characteristics of the children and parents, social factors and parental concerns/perceptions concerning their child's weight status were considered. Further selective misreporting was addressed, investigating food group intakes commonly perceived as more or less socially desirable. Proportions of under-, plausible and over-reports were 8·0, 88·6 and 3·4 %, respectively. The risk of under-reporting increased with age (OR 1·19, 95 % CI 1·05, 1·83), BMI z-score of the child (OR 1·23, 95 % CI 1·10, 1·37) and household size (OR 1·12, 95 % CI 1·01, 1·25), and was higher in low/medium income groups (OR 1·45, 95 % CI 1·13, 1·86). Over-reporting was negatively associated with BMI z-scores of the child (OR 0·78, 95 % CI 0·69, 0·88) and higher in girls (OR 1·70, 95 % CI 1·27, 2·28). Further social desirability and parental concerns/perceptions seemed to influence the reporting behaviour. Future studies should involve these determinants of misreporting when investigating diet–disease relationships in children to correct for the differential reporting bias. [ABSTRACT FROM PUBLISHER]

What is already known about this subject Parents of children with overweight and obesity tend to underestimate their children's weight., Most studies show no association between parental education level and accurate parental perception of a child's weight category., Studies show no consistent relationship between parental weight perception and the child's gender., What this study adds Parental underestimation of children's weight category for children in the overweight and obesity categories was found across eight European countries., Regional differences indicated a more accurate parental weight perception in Northern and Central Europe., A high proportion of parents in Southern Europe were concerned about future underweight or overweight in their children., Objectives To evaluate parental perceptions of and concern about child's body weight and general health in children in a European cohort. Design Cross-sectional multi-centre study in eight European countries. Participants 16 220 children, ages 2-9 years. Methods Parents completed a questionnaire regarding children's health and weight and concern about overweight and underweight. Objective children's weight categories from the International Obesity Task Force were used. Logistic regression models were utilized to identify predictors of accurate weight perception. Results Parental weight perception corresponded overall to children's mean body mass index ( BMI) z-scores, with important exceptions. About one-third of the total indicated concern about underweight, paradoxically most often parents of children in the overweight or obesity categories. In 63%, parents of children in the overweight category marked 'proper weight'. The strongest predictor for accurate parental weight perception for children with overweight and obesity was BMI z-score (odds ratio [ OR] = 7.2, 95% confidence interval [ CI] 6.1-8.7). Compared to Southern Europe, ORs for accurate parental weight perception were 4.4 (95% CI 3.3-6.0) in Northern Europe and 3.4 (95% CI 2.7-4.2) in Central Europe. Conclusion Parents of children categorized as being overweight or obese systematically underestimated weight. Parents differed regionally regarding accurate weight perception and concern about overweight and underweight. [ABSTRACT FROM AUTHOR]

Purpose: High-dimensional propensity score (hd-PS) adjustment has been proposed as a tool to improve control for confounding in pharmacoepidemiological studies using longitudinal claims databases. We investigated whether hd-PS matching improved confounding by indication in a study of Cox-2 inhibitors (coxibs) and traditional nonsteroidal anti-inflammatory drugs (tNSAIDs) and their association with the risk of upper gastrointestinal complications (UGIC). Methods: In a cohort study of new users of coxibs and tNSAIDs we compared the effectiveness of these drugs to reduce UGIC using hd-PS matching and conventional propensity score (PS) matching in the German Pharmacoepidemiological Research Database. Results: The unadjusted rate ratio (RR) of UGIC for coxib users versus tNSAID users was 1.21 [95 % confidence interval (CI) 0.91-1.61]. The conventional PS matched cohort based on 79 investigator-identified covariates resulted in a RR of 0.84 (0.56-1.26). The use of the hd-PS algorithm based on 900 empirical covariates further decreased the RR to 0.62 (0.43-0.91). Conclusions: A comparison of hd-PS matching versus conventional PS matching resulted in improved point estimates for studying an intended treatment effect of coxibs versus tNSAIDs when benchmarked against results from randomized controlled trials. [ABSTRACT FROM AUTHOR]

Objective: Measurement errors in dietary data lead to attenuated estimates of associations between dietary exposures and health outcomes. The present study aimed to compare and evaluate different approaches of handling implausible reports by exemplary analysis of the association between dietary intakes (total energy, soft drinks, fruits/vegetables) and overweight/obesity in children.Design: Cross-sectional multicentre study.Setting: Kindergartens/schools from eight European countries participating in the IDEFICS Study.Subjects: Children (n 5357) aged 2-9 years who provided one 24 h dietary recall and complete covariate information.Results: The 24 h recalls were classified into three reporting groups according to adapted Goldberg cut-offs: under-report, plausible report or over-report. In the basic logistic multilevel model (adjusted for age and sex, including study centre as random effect), the dietary exposures showed no significant association with overweight/obesity (energy intake: OR=0·996 (95 % CI 0·983, 1·010); soft drinks: OR = 0·999 (95 % CI 0·986, 1·013)) and revealed even a positive association for fruits/vegetables (OR = 1·009 (95 % CI 1·001, 1·018)). When adding the reporting group (dummy variables) and a propensity score for misreporting as adjustment terms, associations became significant for energy intake as well as soft drinks (energy: OR = 1·074 (95 % CI 1·053, 1·096); soft drinks: OR = 1·015 (95 % CI 1·000, 1·031)) and the association between fruits/vegetables and overweight/obesity pointed to the reverse direction compared with the basic model (OR = 0·993 (95 % CI 0·984, 1·002)).Conclusions: Associations between dietary exposures and health outcomes are strongly affected or even masked by measurement errors. In the present analysis consideration of the reporting group and inclusion of a propensity score for misreporting turned out to be useful tools to counteract attenuation of effect estimates. [ABSTRACT FROM AUTHOR]

What is already known about this subject Overweight and obesity can be linked to different parental socioeconomic factors already in very young children., In Western developed countries, the association of childhood overweight and obesity and parental socioeconomic status shows a negative gradient., Ambiguous results have been obtained regarding the association between socioeconomic factors and childhood overweight and obesity in different countries and over time., What this study adds European regions show heterogeneous associations between socioeconomic factors and overweight and obesity in a multi-centre study with highly standardized study protoco., The strength of association between SES and overweight and obesity varies across European regions., In our study, the SES gradient is correlated with the regional mean income and the country-specific Human development index indicating a strong influence not only of the family but also of region and country on the overweight and obesity prevalence., Objective To assess the association between different macro- and micro-level socioeconomic factors and childhood overweight. Methods Data from the IDEFICS baseline survey is used to investigate the cross-sectional association between socioeconomic factors, like socioeconomic status ( SES), and the prevalence of childhood overweight. Differences and similarities regarding this relationship in eight European regions (located in Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden) are explored. 11 994 children (50.9% boys, 49.1% girls) and their parents were included in the analyses. Results In five of the eight investigated regions (in Belgium, Estonia, Germany, Spain and Sweden), the prevalence of childhood overweight followed an inverse SES gradient. In the other three regions (in Cyprus, Hungary and Italy), no association between SES and childhood overweight was found. The SES-overweight association in a region was best explained by the country-specific human development index and the centre-specific mean income. For the investigated association between other socioeconomic factors and overweight, no clear pattern could be found in the different regions. Conclusion The association between socioeconomic factors and childhood overweight was shown to be heterogeneous across different European regions. Further research on nationwide European data is needed to confirm the results and to identify target groups for prevention. [ABSTRACT FROM AUTHOR]

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Background:The European IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study was set up to determine the aetiology of overweight, obesity and related disorders in children, and to develop and evaluate a tailored primary prevention programme.Objective:This paper focuses on the aetiological element of the multicentre study, the measures and examinations, sociodemographic characteristics of the study sample and proportions of participation.Design:Prospective cohort study with an embedded intervention study that started with a baseline survey in eight countries in 2007-2008.Subjects and measurements:Baseline participants of the prospective cohort study were 16 224 children aged 2-9 years. Parents reported sociodemographic, behavioural, medical, nutritional and other lifestyle data for their children and families. Examinations of children included anthropometry, blood pressure, fitness, accelerometry, DNA from saliva and physiological markers in blood and urine. The built environment, sensory taste perception and other mechanisms of children's food choices and consumer behaviour were studied in subgroups.Results:Between 1507 and 2567, children with a mean age of 6.0 years and an even sex distribution were recruited from each country. Of them, 82% lived in two-parent families. The distribution of standardised income levels differed by study sample, with low-income groups being strongly represented in Cyprus, Italy and Germany. At least one 24-h dietary recall was obtained for two-thirds of the children. Blood pressure and anthropometry were assessed in more than 90%. A 3-day accelerometry was performed in 46%, motor fitness was assessed in 41%, cardiorespiratory fitness in 35% and ∼11% participated in taste perception tests. The proportion of children donating venous blood, urine and saliva was 57, 86 and 88%, respectively.Conclusion:The IDEFICS cohort provides valuable data to investigate the interplay of social, environmental, genetic, physiological and behavioural factors in the development of major diet- and lifestyle-related disorders affecting children at present. [ABSTRACT FROM AUTHOR]

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Objective:To pool and analyse, according to standardized criteria and using harmonized variables, the existing databases of surveys on childhood overweight and obesity carried out from 1995 to 2005 in different European countries by research groups participating in the IDEFICS project.Methods:Detailed information from seven surveys in five European countries was collected. A common database was built after harmonization of the single studies regarding sample size and age distribution. Variables were critically reviewed and harmonized according to a common protocol. On the pooled database, descriptive comparative analyses on the prevalence of overweight/obesity and association analyses of these conditions with perinatal, parental and environmental factors were performed.Results:Starting from total number of 74 871 children, data of 18 626 children were included in the common database (Belgium, n=1766; Cyprus, n=5540; Estonia, n=583; Italy, n=4480 and Sweden, n=6257). After the exclusion of children outside the defined age ranges (4–5 and 9–11 years), the analysis was conducted on 1738 younger and 12 923 older children. Relevant differences in the prevalence of overweight/obesity were observed between countries in both age groups, the highest values being observed in Italy. Age- and gender-related associations between the risk of obesity/overweight and perinatal, parental and environmental factors were observed. An increased risk of high blood pressure in overweight/obese children was consistently observed.Conclusions:The results of this collaborative work of European research centres, although providing potentially useful findings, confirmed that the validity of comparisons between communities depends critically on the comparability of the survey methods. To monitor the current epidemic of childhood obesity and develop appropriate prevention strategies, a coordinated European approach is needed to collect homogeneous sets of epidemiological data. [ABSTRACT FROM AUTHOR]

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Several jackknife estimators of a relative risk in a single 2 × 2 contingency table and of a common relative risk in a 2 × 2 × K contingency table are presented. The estimators are based on the maximum likelihood estimator in a single table and on an estimator proposed by Tarone (1981) for stratified samples, respectively. For the stratified case, a sampling scheme is assumed where the number of observations within each table tends to infinity but the number of tables remains fixed. The asymptotic properties of the above estimators are derived. Especially, we present two general results which under certain regularity conditions yield consistency and asymptotic normality of every jackknife estimator of a bunch of functions of binomial probabilities. [ABSTRACT FROM AUTHOR]

Summary This article investigates the performance of two jackknife techniques under an asymptotic model in which the number of 2 x 2 tables increases but the possible marginal configurations remain fixed. These approaches are applied to the Mantel-Haenszel estimator, or transformed versions of this estimator, respectively. The resulting jackknife estimators are shown to be consistent for the common odds ratio. Their asymptotic distributions are derived; they can be used for constructing appropriate sparse-data confidence intervals. [ABSTRACT FROM AUTHOR]

The property of invariance—well-known for a single test problem—is extended to multiple test problems. It is shown that the invariance of the components of a multiple test is necessary and sufficient for the multiple test to be invariant. Furthermore, the invariance of stepwise procedures is investigated. An example is given addressing some related aspects. [ABSTRACT FROM AUTHOR]

In the situation of stratified 2×2 tables, consitency of two different jackknife variances of the Mantel-Haenszel estimator is discussed in the case of increasing sample sizes, but a fixed number of strata. Different principles for constructing confidence limits for the common odds ratio are investigated from a theoretical point of view with regard to the position and the length of the resulting intervals. Monte Carlo experiments compare the finite sample performance of the consistent jackknife variance with that of other noniterative variance estimators. In addition, the properties of these variance estimators are investigated when used for confidence interval estimation. [ABSTRACT FROM AUTHOR]