Cohort-Based Reference Values for Serum Ferritin and Transferrin and Longitudinal Determinants of Iron Status in European Children Aged 3-15 Years.

BACKGROUND: Reference values of ferritin and transferrin for European children do not exist. OBJECTIVE: We aimed to provide sex-, age-, and body mass index (BMI)-specific serum ferritin and transferrin reference percentiles of 3-15-y-old children based on cohort data and to investigate determinants of iron status. METHODS: A total of 3390 ferritin and 3416 transferrin measurements from children residing in 8 European countries participating in the IDEFICS/I.Family cohort (https://www.isrctn.com/ISRCTN62310987) at baseline (W0) and 6 y later (W3) were used to estimate percentiles using the generalized additive model for location, scale and shape. Associations of serum ferritin and transferrin concentrations with total iron intake, total iron intake additionally adjusted for vitamin C intake, and iron from heme sources were investigated separately with adjustment for sex, age, country of residence, parental education, usual energy intake and BMI z-score in regression models using cross-sectional and longitudinal data. RESULTS: The age-specific ferritin and transferrin 5th and 95th reference percentiles ranged from 10.9 to 81.1 µg/L and 2.23 to 3.56 g/L, respectively. A deficient iron status was observed in 3% of children at W0 and 7% of children and adolescents at W3, respectively. At both waves, a higher iron intake from heme sources was positively associated with serum ferritin {W0: ß = 3.21 [95% confidence interval (CI): 0.71, 5.71]; W3: ß = 4.48 [95% CI: 2.09, 6.87]}, that is, children consuming one mg more heme iron had a 3.21 and 4.48 µg/L higher ferritin concentration. Adherence to a mainly vegetarian diet was associated with a lower chance for sufficient serum ferritin cross-sectionally at W3 [odds ratio (OR) 0.40 (95% CI: 0.21, 0.81)] and longitudinally [OR 0.35 (95% CI: 0.15, 0.93)]. CONCLUSIONS: Age-, sex-, and BMI-specific reference percentiles of serum ferritin and transferrin concentrations based on cohort data are provided for European children aged 3-15 y and may be used in clinical practice.

Improving cardiorespiratory fitness protects against inflammation in children: the IDEFICS study.

BACKGROUND: Muscular and cardiorespiratory fitness (MF and CRF) have been related to inflammation. Thus, the aim of this study was to assess the relationship between fitness and high-sensitivity C-reactive protein (hs-CRP) in European children both in the cross-sectional and longitudinal analysis. METHODS: Three hundred and fifty-seven children (46.2% males) aged 2-9 years with hs-CRP measured, data from MF and CRF, diet quality, objectively measured physical activity (PA) and screen time at baseline and follow-up after 2 years were included. Body mass index z-score (zBMI), waist circumference (WC) and fat mass index (FMI) were assessed. MF and CRF were also dichotomized as follows: low-medium quartiles (Q1-Q3) and highest quartile (Q4). RESULTS: At follow-up, children with the highest CRF (Q4) showed a lower probability of having high hs-CRP. In the longitudinal analysis, children who improved their CRF over time showed a significantly lower probability (p < 0.05) of being in the highest hs-CRP category at follow-up, independently of the body composition index considered: odds ratio (OR) = 0.22 for zBMI, OR = 0.17 for WC, and OR = 0.21 for FMI. CONCLUSIONS: Improving CRF during childhood reduces the odds of an inflammatory profile, independently of body composition and lifestyle behaviours. These highlight the importance of enhancing fitness, especially CRF, to avoid an inflammatory state in children. IMPACT: Improvements in the cardiorespiratory profile during childhood could reverse an unfavourable inflammatory status. There is a longitudinal and inverse association between CRF and inflammation in children. This is the first longitudinal study assessing the relationship between fitness and inflammation during childhood that takes also into account the lifestyle behaviours. Results from the present study suggest a protective role of fitness already in childhood. Efforts to improve fitness in children should be aimed at as inflammation could trigger future cardiovascular disease.

Longitudinal association of childhood physical activity and physical fitness with physical activity in adolescence: insights from the IDEFICS/I.Family study.

BACKGROUND: This study aimed to examine associations of early childhood physical fitness and physical activity (PA) with PA during later childhood/early adolescence while accounting for gender differences. METHODS: We selected data of N = 4329 children from the IDEFICS/I. Family cohort (age 2.4-11.7 years) with data on baseline fitness and accelerometer measurements. At baseline, physical fitness tests were conducted including Flamingo balance, Backsaver sit and reach, Handgrip strength, Standing Long Jump, 40-m sprint and 20-m Shuttle run (to estimate cardio-respiratory fitness levels). PA was measured with Actigraph accelerometers over 3 days at baseline (ActiTrainer or GT1M) and 7 days at follow-up (GT3X). Evenson cutpoints were used to determine moderate-to-vigorous PA (MVPA) time, and children with ≥60mins/day of average MVPA were deemed as having met WHO guidelines at baseline and follow-up. Linear and logistic regressions were performed to examine longitudinal associations between meeting WHO guidelines, MVPA, and physical fitness tests at baseline with meeting WHO guidelines and MVPA at follow-up. Models were conducted on the entire sample, the sex-stratified sample, and stratified by sex and pubertal status at follow-up. RESULTS: Results showed that meeting WHO guidelines for MVPA at baseline was positively associated with MVPA (Standardized Beta (B) = 0.13, 95%CI:(5.6;11.1)) and meeting WHO guidelines at follow-up for the entire sample (OR = 2.1, 95%CI:(1.5; 3.14), and stratified by males (OR = 2.5, 95%CI:(1.5; 4.1)) and females (OR = 1.8, 95%CI:(1.0; 3.2)). This was also found for both male pre/early pubertal and pubertal groups but only in the female pre/early pubertal group, and not the female pubertal group (MVPA: B = .00, 95%CI:(- 6.1; 5.6), WHO: OR = 0.61, 95%CI:(0.23;1.6)). Models indicated that Standing Long jump, 40-m sprint, Shuttle run and Flamingo balance at baseline were associated with MVPA and meeting the guidelines at follow-up. CONCLUSIONS: Meeting WHO guidelines and certain fitness tests at baseline were strongly associated with MVPA and meeting WHO guidelines at follow-up, but this association varied with sex and pubertal status. Consequently, these findings underline the importance of ensuring sufficient physical activity in terms of quality and quantity for children at the earliest stages of life. TRIAL REGISTRATION: ISRCTN62310987.

Dietary intake and meal patterns among young adults with high caries activity: a cross-sectional study.

BACKGROUND: Dental caries is a multifactorial disease that is highly dependent on diet, where a lower consumption and intake frequency of sugar would be favorable. The aims were (i) to examine dietary intake and meal patterns, more specifically sugar intake and foods high in sugar, among young adults with high caries activity, and (ii) to investigate the association between dietary and meal patterns consumption, and level of caries activity. METHODS: This study presents baseline data from an ongoing randomized controlled trial. A total of 50 young adults (aged 23.0 ± 3.0 years) with ≥ 2 decayed tooth surfaces were included. Dietary intake was captured with a 59-item food frequency questionnaire (FFQ) and a three-day food diary. Adherence to dietary guidelines was analyzed by comparing the dietary intake to the Nordic Nutritional Recommendations (NNR) 2012 and by using the Healthy Dietary Adherence score (HDAS). Participants were categorized into two groups: (i) the Caries group with 2-4 decayed surfaces, and (ii) the High caries group with ≥ 5 decayed surfaces. RESULTS: The High caries group reported a statistically significantly higher snack and total meal intake compared to the Caries group, as well as a sugar intake exceeding the Nordic nutritional recommendations. The majority of the participants reported a high intake frequency (> 2.5/day) of sweet foods and drinks and less than one intake of fruit and vegetables, respectively, per day. Similar results were found when analyzing adherence by using the HDAS, where the lowest adherence according to dietary guidelines was shown for the food groups of sugar, whole meal products, and fruit and vegetables. CONCLUSION: The results indicated a high intake of sugar and low intake of fruit, vegetables, and fiber in high caries-active individuals.

Media use trajectories and risk of metabolic syndrome in European children and adolescents: the IDEFICS/I.Family cohort.

BACKGROUND: Media use may influence metabolic syndrome (MetS) in children. Yet, longitudinal studies are scarce. This study aims to evaluate the longitudinal association of childhood digital media (DM) use trajectories with MetS and its components. METHODS: Children from Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden participating in the IDEFICS/I.Family cohort were examined at baseline (W1: 2007/2008) and then followed-up at two examination waves (W2: 2009/2010 and W3: 2013/2014). DM use (hours/day) was calculated as sum of television viewing, computer/game console and internet use. MetS z-score was calculated as sum of age- and sex-specific z-scores of four components: waist circumference, blood pressure, dyslipidemia (mean of triglycerides and HDL-cholesterol-1) and homeostasis model assessment for insulin resistance (HOMA-IR). Unfavorable monitoring levels of MetS and its components were identified (cut-off: ≥ 90th percentile of each score). Children aged 2-16 years with ≥ 2 observations (W1/W2; W1/W3; W2/W3; W1/W2/W3) were eligible for the analysis. A two-step procedure was conducted: first, individual age-dependent DM trajectories were calculated using linear mixed regressions based on random intercept (hours/day) and linear slopes (hours/day/year) and used as exposure measures in association with MetS at a second step. Trajectories were further dichotomized if children increased their DM duration over time above or below the mean. RESULTS: 10,359 children and adolescents (20,075 total observations, 50.3% females, mean age = 7.9, SD = 2.7) were included. DM exposure increased as children grew older (from 2.2 h/day at 2 years to 4.2 h/day at 16 years). Estonian children showed the steepest DM increase; Spanish children the lowest. The prevalence of MetS at last follow-up was 5.5%. Increasing media use trajectories were positively associated with z-scores of MetS (slope: ß = 0.54, 95%CI = 0.20-0.88; intercept: ß = 0.07, 95%CI = 0.02-0.13), and its components after adjustment for puberty, diet and other confounders. Children with increasing DM trajectories above mean had a 30% higher risk of developing MetS (slope: OR = 1.30, 95%CI = 1.04-1.62). Boys developed steeper DM use trajectories and higher risk for MetS compared to girls. CONCLUSIONS: Digital media use appears to be a risk factor for the development of MetS in children and adolescents. These results are of utmost importance for pediatricians and the development of health policies to prevent cardio-metabolic disorders later in life. TRIAL REGISTRATION: ISRCTN, ISRCTN62310987 . Registered 23 February 2018- retrospectively registered.

Trajectories of objectively measured physical activity and childhood overweight: longitudinal analysis of the IDEFICS/I.Family cohort.

BACKGROUND: Since only few longitudinal studies with appropriate study designs investigated the relationship between objectively measured physical activity (PA) and overweight, the degree PA can prevent excess weight gain in children, remains unclear. Moreover, evidence is limited on how childhood overweight determines PA during childhood. Therefore, we analyzed longitudinal trajectories of objectively measured PA and their bi-directional association with weight trajectories of children at 2- and 6-year follow-ups. METHODS: Longitudinal data of three subsequent measurements from the IDEFICS/I.Family cohort study were used to analyze the bi-directional association between moderate-to-vigorous PA (MVPA) and weight status by means of multilevel regression models. Analyses comprised 3393 (2-year follow-up) and 1899 (6-year follow-up) children aged 2-15.9 years from eight European countries with valid accelerometer data and body mass index (BMI) measurements. For categorized analyses, children's weight status was categorized as normal weight or overweight (cutoff: 90th percentile of BMI) and children's PA as (in-) sufficiently active (cutoffs: 30, 45 and 60 min of MVPA per day). RESULTS: Children engaging in at least 60 min MVPA daily at baseline and follow-ups had a lower odds of becoming overweight (odds ratio [OR] at 2-year follow-up: 0.546, 95% CI: 0.378, 0.789 and 6-year follow-up: 0.393, 95% CI: 0.242, 0.638), compared to less active children. Similar associations were found for 45 min MVPA daily. On the other side, children who became overweight had the lowest odds to achieve 45 or 60 min MVPA daily (ORs: 0.459 to 0.634), compared to normal weight children. CONCLUSIONS: Bi-directional associations between MVPA and weight status were observed. In summary, at least 60 min MVPA are still recommended for the prevention of childhood overweight. To prevent excess weight gain, 45 min MVPA per day also showed preventive effects.

Cross-sectional and longitudinal associations between physical activity, sedentary behaviour and bone stiffness index across weight status in European children and adolescents.

BACKGROUND: The associations between physical activity (PA), sedentary behaviour (SB) and bone health may be differentially affected by weight status during growth. This study aims to assess the cross-sectional and longitudinal associations between PA, SB and bone stiffness index (SI) in European children and adolescents, taking the weight status into consideration. METHODS: Calcaneus SI was first measured by quantitative ultrasound among children aged 2-9 years old in 2007/08. It was measured again after 2 years in the IDEFICS study and after 6 years in the I. Family study. A sample of 2008 participants with time spent at sports clubs, watching TV and playing computer/games self-reported by questionnaire, and a subsample of 1037 participants with SB, light PA (LPA) and moderate-to-vigorous PA (MVPA) objectively measured using Actigraph accelerometers were included in the analyses. Weight status was defined as thin/normal and overweight/obese according to the extended International Obesity Task Force criteria. Linear mixed-effects models were used to estimate the cross-sectional and longitudinal associations between PA, SB and SI percentiles, stratified by weight status. RESULTS: The cross-sectional association between weekly duration of watching TV and SI percentiles was negative in thin/normal weight group (ß = - 0.35, p = 0.008). However, baseline weekly duration of watching TV (ß = - 0.63, p = 0.021) and change after 2 years (ß = - 0.63, p = 0.022) as well as the change in weekly duration of playing computer/games after 6 years (ß = - 0.75, p = 0.019) were inversely associated with corresponding changes in SI percentiles in overweight/obese group. Change in time spent at sports clubs was positively associated with change in SI percentiles after 2 years (ß = 1.28, p = 0.001), with comparable effect sizes across weight status. In the subsample with accelerometer data, we found a positive cross-sectional association between MVPA and SI percentiles in thin/normal weight group. Baseline MVPA predicted changes in SI percentiles after 2 and 6 years in all groups. CONCLUSIONS: Our results suggested the beneficial effect of PA on SI. However, the increasing durations of screen-based SB might be risk factors for SI development, especially in overweight/obese children and adolescents.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents.

BACKGROUND: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. METHODS: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2-18 years) from 18 different European countries. RESULTS: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. CONCLUSIONS: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

Predictive associations between lifestyle behaviours and dairy consumption: The IDEFICS study.

BACKGROUND AND AIM: Physical activity (PA) and sedentary behaviours (SB) are related to obesity and cardiometabolic risk; however, the literature is controversial regarding the effect of dairy consumption on the development of cardiovascular disease (CVD) risk factors. The aim of this study was to assess longitudinally the relationship between specific lifestyle behaviours (PA and SB) and dairy consumption in a sample of European children and adolescents. METHODS AND RESULTS: Children from the IDEFICS study were included in the analyses. Two measurements, with 2 years' interval, were conducted. A total of 1688 (50.8% boys) children provided information regarding diet, measured by a 24-h dietary recall, PA measured by accelerometers and parent-reported sedentary screen time (SST) at both time points. Different combinations of these behaviours, at each survey and over time, were derived applying specific recommendations. Multilevel ordinal logistic regression and analysis of covariance were used to assess their association with dairy consumption, adjusted for potential confounders. Differences by gender were found regarding dairy product consumption and also adherence to SB and PA recommendations at T0 and T1. Children meeting both lifestyle recommendations, at the two measurement points, had higher probability to consume more milk and yogurt and less cheese than the rest of combinations. CONCLUSIONS: These results suggest that European children with a healthy lifestyle, especially regarding PA and SB over time, consumed more milk and yogurt. This study suggests that the protective effect of specific dairy products found in literature could be partially due to the association of their consumption with specific healthy lifestyles.

Development and body mass inversely affect children's brain activation in dorsolateral prefrontal cortex during food choice.

Childhood obesity is a rising problem caused in part by unhealthy food choices. Food choices are based on a neural value signal encoded in the ventromedial prefrontal cortex, and self-control involves modulation of this signal by the dorsolateral prefrontal cortex (dlPFC). We determined the effects of development, body mass (BMI Cole score) and body mass history on the neural correlates of healthy food choice in children. 141 children (aged 10-17y) from Germany, Hungary and Sweden were scanned with fMRI while performing a food choice task. Afterwards health and taste ratings of the foods were collected. In the food choice task children were asked to consider the healthiness or tastiness of the food or to choose naturally. Overall, children made healthier choices when asked to consider healthiness. However, children who had a higher weight gain per year chose less healthy foods when considering healthiness but not when choosing naturally. Pubertal development stage correlated positively while current body mass correlated negatively with dlPFC activation when accepting foods. Pubertal development negatively and current body mass positively influenced the effect of considering healthiness on activation of brain areas involved in salience and motivation. In conclusion, children in earlier stages of pubertal development and children with a higher body weight exhibited less activation in the dlPFC, which has been implicated in self-control during food choice. Furthermore, pubertal development and body mass influenced neural responses to a health cue in areas involved in salience and motivation. Thus, these findings suggest that children in earlier stages of pubertal development, children with a higher body mass gain and children with overweight may possibly be less susceptible to healthy eating interventions that rely on self-control or that highlight health aspects of food.

Urban Moveability and physical activity in children: longitudinal results from the IDEFICS and I.Family cohort.

BACKGROUND: Physical activity (PA) is one of the major protective behaviours to prevent non-communicable diseases. Positive effects of the built environment on PA are well investigated, although evidence of this association is mostly based on cross-sectional studies. The present study aims to investigate the longitudinal effects of built environment characteristics in terms of a moveability index on PA of children in their transition phase to adolescence using data of the IDEFICS/I.Family cohort. METHODS: We used data on 3394 accelerometer measurements of 2488 children and adolescents aged 3 to 15 years old from survey centres of three countries, Germany, Italy, and Sweden, who participated in up to three surveys over 6 years. In network-dependent home neighbourhoods, a moveability index was calculated based on residential density, land use mix, street connectivity, availability of public transport and public open spaces such as green spaces and public playgrounds in order to quantify opportunities for PA of children and adolescents. Linear trajectories of light PA (LPA) and moderate-to-vigorous PA (MVPA) were estimated using linear mixed models accounting for repeated measurements nested within individuals. Least squares means were estimated to quantify differences in trajectories over age. RESULTS: LPA and MVPA declined annually with age by approximately 20 min/day and 2 min/day respectively. In girls, the moveability index showed a consistent significantly positive effect on MVPA ([Formula: see text] = 2.14, 95% CI: (0.11; 4.16)) for all ages, while in boys the index significantly lessened the decline in LPA with age for each year. ([Formula: see text] = 2.68, 95% CI: (0.46; 4.90)). Availability of public open spaces was more relevant for MVPA in girls and LPA in boys during childhood, whereas in adolescence, residential density and intersection density became more important. CONCLUSION: Built environment characteristics are important determinants of PA and were found to have a supportive effect that ameliorates the decline in PA during the transition phase from childhood to adolescence. In childhood environmental support for leisure time PA through public open spaces was found to be the most protective factor whereas in adolescence the positive influence of street connectivity and residential density was most supportive of physical activity.

Urinary sucrose and fructose to validate self-reported sugar intake in children and adolescents: results from the I.Family study.

PURPOSE: Excessive consumption of free sugar increases the risk for non-communicable diseases where a proper assessment of this intake is necessary to correctly estimate its association with certain diseases. Urinary sugars have been suggested as objective biomarkers for total and free sugar intake in adults but less is known about this marker in children and adolescents. Therefore, the aim of this exploratory study is to evaluate the relative validity of self-reported intake using urinary sugars in children and adolescents. METHODS: The study was conducted in a convenience subsample of 228 participants aged 5-18 years of the I.Family study that investigates the determinants of food choices, lifestyle and health in European families. Total, free and intrinsic sugar intake (g/day) and sugar density (g/1000 kcal) were assessed using 24-h dietary recalls (24HDRs). Urinary sucrose (USUC) and urinary fructose (UFRU) were measured in morning urine samples and corrected for creatinine excretion (USUC/Cr, UFRU/Cr). Correlation coefficients, the method of triads and linear regression models were used to investigate the relationship between intake of different types of sugar and urinary sugars. RESULTS: The correlation between usual sugar density calculated from multiple 24HDRs and the sum of USUC/Cr and UFRU/Cr (USUC/Cr + UFRU/Cr) was 0.38 (p < 0.001). The method of triads revealed validity coefficients for the 24HDR from 0.64 to 0.87. Linear regression models showed statistically significant positive associations between USUC/Cr + UFRU/Cr and the intake of total and free sugar. CONCLUSIONS: These findings support the relative validity of total and free sugar intake assessed by self-reported 24HDRs in children and adolescents.

Time trends in nutrient intake and dietary patterns among five birth cohorts of 70-year-olds examined 1971-2016: results from the Gothenburg H70 birth cohort studies, Sweden.

BACKGROUND: Nutrition is a key factor in healthy ageing but there are still gaps in knowledge about risk- and protective factors linking diet and healthy ageing. The aim of this study was to investigate time trends in dietary patterns and nutrient intake in an older population, in order to increase the understanding of whether dietary recommendations are followed and if nutrient needs are met. METHODS: Cross-sectional data was derived from five samples of 70-year-olds examined 1971-72, 1981-83, 1992-93, 2000-02 and 2014-16 from the Gothenburg H70 birth cohort studies in Sweden. A total of 2246 individuals (56% women) participated. Dietary intake was determined by the diet history method, which is an interview including questions on usual frequencies and portion sizes of food intake during the preceding three months. Recommended values of nutrient intake and determinants of healthful dietary patterns were based on the Nordic Nutrition Recommendations 2012. Statistical analyses were performed using general linear models, student's t-test and chi-square test, stratified by sex. RESULTS: The intake of fruits and vegetables, fish and seafood, whole grain products and nuts and seeds increased during the study period (p < 0.0001), among both sexes. However, there was also an increase in alcohol intake (p < 0.0001), especially from wine and beer, and in 2014-16 more than 30% had an alcohol intake above recommendations. Protein intake increased (p < 0.0001 for women and p = 0.0004 for men), and 48% of the women and 37% of the men had a protein intake above recommended 1.2 g/kg body weight and day in 2014-16. The proportion of participants at risk of inadequate intake of vitamins C, D and folate decreased during the study period, among both sexes (p < 0.0001). However, vitamin D intake from diet was still below average requirement level of 7.5 µg/day for 49% of the women and 32% of the men in 2014-16. CONCLUSIONS: Dietary patterns have changed among 70-year-olds during the past five decades, with an increase in healthful foods and a higher nutrient density in later born birth cohorts. However, the intake of alcohol increased, especially among women. Results from this study can be useful as a basis for dietary guidelines and used for prevention strategies involving older adults in population-based and health care settings.

Associations between exclusive breastfeeding and physical fitness during childhood.

PURPOSE: Exposure to breastfeeding improves the survival, health, and development of children; therefore, breast milk is recommended as the exclusive nutrient source for feeding term infants during the first 6 months. This cross-sectional study aimed to determine the possible association between exposure to exclusive breastfeeding and physical fitness performance in children and, if so, whether this association is influenced by the breastfeeding duration. METHODS: A total of 2853 (52.3 % girls) European children from the IDEFICS study aged 6-11 years with complete data on physical fitness (cardiorespiratory fitness, muscular strength, flexibility, balance, speed) and exclusive breastfeeding duration (never, 1-3, 4-6, 7-12 months) were included in the present study. Multivariate and mixed linear regression models were estimated and adjusted for sex, age, birth weight, diet, physical activity, body mass index, and parental factors (age, body mass index, educational attainment). RESULTS: We found a positive association between exclusive breastfeeding and lower-body explosive strength (ß = 0.034) as well as flexibility (ß = 0.028). We also found a positive association between breastfeeding and balance in boys (ß = 0.039), while this association was negative in girls (ß = -0.029). To improve lower-body explosive strength, 1-3 months of exclusive breastfeeding were enough; a longer duration did not lead to increasing benefit. In contrast, 4-6 months of breastfeeding were necessary to have any benefit on flexibility or balance, although this became nonsignificant after adjustment for body mass index and physical activity. CONCLUSIONS: Exclusive breastfeeding seems a natural way of slightly improving some physical fitness components (mainly lower-body muscle strength) and thus future health.

Food and beverage intakes according to physical activity levels in European children: the IDEFICS (Identification and prevention of Dietary and lifestyle induced health EFfects In Children and infantS) study.

OBJECTIVE: Physical activity (PA) levels and dietary habits are considered some of the most important factors associated with obesity. The present study aimed to examine the association between PA level and food and beverage consumption in European children (2-10 years old).Design/Setting/SubjectsA sample of 7229 children (49·0 % girls) from eight European countries participating in the IDEFICS (Identification and prevention of Dietary and lifestyle induced health EFfects In Children and infantS) study was included. Moderate-to-vigorous PA (MVPA) was assessed objectively with accelerometers. FFQ was used to register dietary habits. ANCOVA and binary logistic regression were applied. RESULTS: Boys who spent less time in MVPA reported lower consumption of vegetables, fruits, cereals, yoghurt, milk, bread, pasta, candies and sugar-sweetened beverages (SSB) than boys who spent more time in MVPA (P<0·05). Moreover, boys who spent less time in MVPA were more likely to consume fast foods and water than those in the highest MVPA tertile (P<0·05). Girls who spent less time in MVPA reported lower consumption frequencies of vegetables, pasta, bread, yoghurt, candies, jam/honey and SSB than girls in the highest MVPA tertile (P<0·05). Also, girls in the lowest MVPA tertile were more likely to consume fast foods and water than those with high levels of MVPA (P<0·05). CONCLUSIONS: Food intake among European children varied with different levels of daily MVPA. Low time spent in MVPA was associated with lowest consumption of both high- and low-energy-dense foods and high fast-food consumption.

Association of desaturase activity and C-reactive protein in European children.

BACKGROUND: Desaturase enzymes influence the fatty acid (FA) composition of body tissues and their activity affects the conversion rate of saturated to monounsaturated FA and of polyunsaturated FA (PUFA) to long-chain PUFA. Desaturase activity has further been shown to be associated with inflammation. We investigate the association between delta-9 (D9D), delta-6 (D6D) and delta-5 desaturase (D5D) activity and high-sensitive C-reactive protein (CRP) in young children. METHODS: In the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cohort study children were examined at baseline (T0) and after 2 y (T1). D9D, D6D, and D5D activities were estimated from T0 product-precursor FA ratios. CRP was measured at T0 and T1. In a subsample of 1,943 children with available information on FA, CRP, and covariates, the cross-sectional and longitudinal associations of desaturase activity and CRP were analyzed. RESULTS: Cross-sectionally, a D9D increase of 0.01 units was associated with a 11% higher risk of having a serum CRP ≥ Percentile 75 (P75) (OR, 99% CI: 1.11 (1.01; 1.22)) whereas D6D and D5D were not associated with CRP. No significant associations were observed between baseline desaturase activity and CRP 2 y later. CONCLUSION: Cross-sectionally, our results indicate a positive association of D9D and CRP independent of weight status. High D9D activity may increase the risk of subclinical inflammation which is associated with metabolic disorders. As D9D expression increases with higher intake of saturated FA and carbohydrates, dietary changes may influence D9D activity and thus CRP. However, it remains to be investigated whether there is a causal relationship between D9D activity and CRP.

Palatable food consumption in children: interplay between (food) reward motivation and the home food environment.

To understand the importance of the home food environment on unhealthy food consumption in children high in reward sensitivity, this study tested the hypothesis that the home availability of unhealthy food moderates the effect of reward sensitivity on children's fast-food consumption frequency, exerted via food cue responsiveness. Children between 7.5 and 14 years (n = 174, 50.6% boys) reported on reward sensitivity and food cue responsiveness (by means of the subscale 'external eating'). Their height and weight were measured. Parents reported on their children's fast-food consumption frequency, food cue responsiveness (by means of the subscale 'food responsiveness'), and on the home availability of unhealthy foods. Two moderated mediation models were conducted, one with the parent- and one with the child-reported food cue responsiveness as mediator. Findings suggested that with a high home availability of unhealthy foods, (a) a higher fast-food consumption frequency was found in children high in reward sensitivity and (b) the relation between reward sensitivity and the fast-food consumption frequency was mediated by external eating. CONCLUSIONS: The findings point at the importance of the home food environment in children high in reward sensitivity. They suggest to limit the home availability of unhealthy foods. What is Known: • Reward sensitivity (RS) is positively associated with children's palatable food consumption • In adolescents, this effect is mediated by food cue responsiveness, which determines the strength of an individual's motivation to obtain food when perceiving food cues What is New: • Children high in RS may be more vulnerable to palatable food cues in their everyday food environment because of a higher food cue responsiveness • The home food environment may be an important determining factor of the palatable food consumption of these children.

Prospective associations between dietary patterns and body composition changes in European children: the IDEFICS study.

OBJECTIVE: To describe dietary patterns by applying cluster analysis and to describe the cluster memberships of European children over time and their association with body composition changes. DESIGN: The analyses included k-means clustering based on the similarities between the relative frequencies of consumption of forty-three food items and regression models were fitted to assess the association between dietary patterns and body composition changes. SETTING: Primary schools and pre-schools of selected regions in Italy, Estonia, Cyprus, Belgium, Sweden, Hungary, Germany and Spain. SUBJECTS: Participants (n 8341) in the baseline (2-9 years old) and follow-up (4-11 years old) surveys of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) study. RESULTS: Three persistent clusters were obtained at baseline and follow-up. Children consistently allocated to the 'processed' cluster presented increased BMI (ß=0·050; 95 % CI 0·006, 0·093), increased waist circumference (ß=0·071; 95 % CI 0·001, 0·141) and increased fat mass gain (ß=0·052; 95 % CI 0·014, 0·090) over time v. children allocated to the 'healthy' cluster. Being in the 'processed'-'sweet' cluster combination was also linked to increased BMI (ß=0·079; 95 % CI 0·015, 0·143), increased waist circumference (ß=0·172; 95 % CI 0·069, 0·275) and increased fat mass gain (ß=0·076; 95 % CI 0·019, 0·133) over time v. the 'healthy' cluster. CONCLUSIONS: Children consistently showing a processed dietary pattern or changing from a processed pattern to a sweet pattern presented the most unfavourable changes in fat mass and abdominal fat. These findings support the need to promote overall healthy dietary habits in obesity prevention and health promotion programmes targeting children.

Bidirectional associations between psychosocial well-being and adherence to healthy dietary guidelines in European children: prospective findings from the IDEFICS study.

BACKGROUND: In children the relationship between a healthy diet and psychosocial well-being has not been fully explored and the existing evidence is inconsistent. This study investigates the chronology of the association between children's adherence to healthy dietary guidelines and their well-being, with special attention to the influence of weight status on the association. METHODS: Seven thousand six hundred seventy five children 2 to 9 years old from the eight-country cohort study IDEFICS were investigated. They were first examined between September 2007 and June 2008 and re-examined again 2 years later. Psychosocial well-being was measured using self-esteem and parent relations questions from the KINDL® and emotional and peer problems from the Strengths and Difficulties Questionnaire. A Healthy Dietary Adherence Score (HDAS) was calculated from a 43-item food frequency questionnaire as a measure of the degree to which children's dietary intake follows nutrition guidelines. The analysis employed multilevel logistic regression (country as random effect) with bidirectional modeling of dichotomous dietary and well-being variables as both exposures and outcomes while controlling for respective baseline values. RESULTS: A higher HDAS at baseline was associated with better self-esteem (OR 1.2, 95% CI 1.0;1.4) and fewer emotional and peer problems (OR 1.2, 95% CI 1.1;1.3 and OR 1.3, 95% CI 1.2;1.4) 2 years later. For the reversed direction, better self-esteem was associated with higher HDAS 2 years later (OR 1.1 95% CI 1.0;1.29). The analysis stratified by weight status revealed that the associations between higher HDAS at baseline and better well-being at follow-up were similar in both normal weight and overweight children. CONCLUSION: Present findings suggest a bidirectional relation between diet quality and self-esteem. Additionally, higher adherence to healthy dietary guidelines at baseline was associated with fewer emotional and peer problems at follow-up, independent of children's weight status.

Further evidence for the role of pregnancy-induced hypertension and other early life influences in the development of ADHD: results from the IDEFICS study.

The aim of this study is to investigate whether in addition to established early risk factors other, less studied pre-, peri-, and postnatal influences, like gestational hypertension or neonatal respiratory disorders and infections, may increase a child's risk of developing attention-deficit/hyperactivity disorders (ADHD). In the IDEFICS study more than 18,000 children, aged 2-11.9 years, underwent extensive medical examinations supplemented by parental questionnaires on pregnancy and early childhood. The present analyses are restricted to children whose parents also completed a supplementary medical questionnaire (n = 15,577), including the question whether or not the child was ever diagnosed with ADHD. Multilevel multivariable logistic regression was used to assess the association between early life influences and the risk of ADHD. Our study confirms the well-known association between maternal smoking during pregnancy and a child's risk of ADHD. In addition, our study showed that children born to mothers younger than 20 years old were 3-4 times more likely to develop ADHD as compared to children born to mothers aged 25 years and older. Moreover, we found that children whose mothers suffered from pregnancy-induced hypertension had an approximately twofold risk of ADHD (OR 1.95; 95% CI 1.09-3.48). This also holds true for infections during the first 4 weeks after birth (OR 2.06; 95% CI 1.05-4.04). In addition, although not statistically significant, we observed a noticeable elevated risk estimate for neonatal respiratory disorders (OR 1.76; 95% CI 0.91-3.41). Hence, we recommend that these less often studied pre-, peri, and postnatal influences should get more attention when considering early indicators or predictors for ADHD in children. However, special study designs such as genetically sensitive designs may be needed to derive causal conclusions.