Assessment of selection bias in a health survey of children and families - the IDEFICS Sweden-study

Effects of the COVID-19 pandemic on the physical activity and screen time habits of children aged 11-13 years in Sweden

Introduction

Physical activity (PA), exercise, sedentary behavior and screen time are lifestyle factors that have been shown to significantly impact child health in different ways. These lifestyle factors were affected to different degrees by global restrictions during the COVID-19 pandemic. We investigated PA and screen time in a cohort of Swedish children in both 2019 and 2021, before and during the pandemic.

Method

Adolescents born in 2008 in Halland, Sweden, and included in a previous longitudinal birth cohort study were invited to take part in follow-up questionnaires about PA, screen time and COVID-19. A total of 1041 children aged 11 (in 2019) and 13 years (in 2021) replied and 777 of them answered on both occasions.

Results

Most children (42.1%) reported that their leisure time PA was unchanged from 2019 to 2021. Compared to unchanged PA 33.9% exercised more often (p = 0.011) and 23.9% exercised less (p < 0.001), both differences statistically significant. Roughly, 43.2% of boys and 34.9% of girls in 2021 exercised so that they became breathless or broke a sweat at least 4 times a week not counting physical education in school, corresponding figures for 2019 were 38.2% for boys and 35.2% for girls. The majority of children were able to continue attending leisure time sports clubs during the pandemic, but participation decreased from 88.3% to 76.3% from 11 to 13 years of age. Most reported that sports club routines changed during the pandemic, but only 40.9% reported fewer practice opportunities. Attending a sports club gave greater protection against loss of PA during the pandemic than not belonging to one (41.0% vs. 23.2%, p < 0.001). The majority (71.1%) of children spent more time on screens in 2021 than 2019, with a mean increase of 9.4 h (95% CI 8.6 to 10.2 h) from 20.7 to 30.1 hours per week (p < 0.001) during the study.

Conclusions

Swedish children largely maintained their levels of PA during the pandemic at 13 years of age and these were possibly safeguarded by the comparably mild pandemic restrictions in Sweden in 2021. However, they did increase their screen time between 11 and 13 years of age.

Dietary intake, physical activity and sedentary behavior and association with BMI during the transition to parenthood: a prospective dyadic study

Introduction

Little is known on how diet, physical activity (PA) and sedentary behavior (SB) changes during pregnancy and after childbirth in primiparous couples. Moreover, it is unclear how potential behavioral changes are associated with changes in BMI. This study examined changes in diet, PA and SB, and their association with changes in BMI in couples transitioning to parenthood.

Methods

Dietary intake (FFQ), PA, SB (both Actigraph GT3X accelerometers) and BMI of women and men were assessed at 12 weeks of gestation, 6 weeks and 6 months postpartum. Data were analyzed using dyadic longitudinal data analyses techniques.

Results

In women, a decrease in fruit intake, an increase in alcohol intake, an increase of light-intensity PA, and a decrease in SB were observed from the beginning of pregnancy up to 6 months postpartum. Decreases in fruit intake between 6 weeks and 6 months postpartum was associated with increases in BMI. Men did not show significant dietary changes, while an increase in light-intensity PA and a decrease in moderate-to-vigorous PA (MVPA) was observed at 6 months postpartum when compared to 12 weeks of gestation. Paternal increases in "avoidance food group" intake were associated with increases in BMI between baseline and 6 weeks postpartum. No associations of changes in BMI and changes in PA and SB were found.

Discussion

Not only mothers but also fathers experienced unfavorable changes in lifestyle during the transition to parenthood, with impact on BMI changes. This highlights the need to monitor unhealthy changes in lifestyle and body weight in both parents when expecting a child and after childbirth.

Clinical trial registration

Clinicaltrials.gov, NCT03454958.

Changes in maternal and paternal body composition during the transition to parenthood (TRANSPARENTS)

OBJECTIVE

The transition to parenthood might negatively influence health-related behavior and can result in increased adiposity. The aim of this study was to investigate how body composition in mother-father dyads changes from pregnancy up to 6 months post partum.

METHODS

Anthropometrics were collected from 144 nulliparous couples at 12 weeks of gestation (PG12) and 6 weeks (PP6WK) and 6 months (PP6M) post partum. A longitudinal dyadic confirmatory factor analysis model was used to analyze changes in body composition. Body composition was treated as a latent variable using BMI, body fat percentage, and waist circumference as indicators.

RESULTS

For women, latent means increased at 6 weeks post partum (PP6WK - PG12: +1.115, SE: 0.117, p < 0.001), decreased again at 6 months post partum (PP6M - PP6WK: -0.368, SE: 0.107, p < 0.001), but remained above baseline levels (PP6M - PG12: +0.747; SE: 0.115, p < 0.001). For men, the latent means at follow-up were higher than at baseline (PP6WK-PG12: +0.370, SE: 0.075; PP6M-PG12: +0.366, SE: 0.084, both p < 0.001).

CONCLUSIONS

Increases in latent means correspond to unfavorable changes in BMI, body fat percentage, and waist circumference. These changes were observed from the beginning of pregnancy up to 6 months post partum. Weight management for both women and men during pregnancy and the early postpartum period is recommended and fathers should be included in pre- and postnatal standard care.

Recommendations for the Development of Family-Based Interventions Aiming to Prevent Unhealthy Changes in Energy Balance-Related Behavior during the Transition to Parenthood: A Focus Group Study

Feasible interventions addressing unhealthy changes in energy balance-related behavior (EBRB) during pregnancy and early postpartum are needed. This study identified the needs and wishes of expecting and first-time parents concerning EBRB interventions during the transition to parenthood. Thirteen focus group discussions (n = 74) were conducted. Couples provided information about whether an intervention targeting unhealthy EBRB changes during pregnancy and postpartum would be acceptable, how such an intervention should look like, and in which way and during which period they needed support. Guided by the TiDIER checklist, all quotes were divided into five main categories (i.e., ‘what’, ‘how’, ‘when and how much’, ‘where’, ‘for and from whom’). Interventions should aim for changes at the individual, social, environmental and policy levels. The accessibility and approach (indirect or face-to-face) together with communicational aspects should be taken into account. A focus should go to delivering reliable and personalized information and improving self-regulation skills. Interventions should be couple- or family-based. Authorities, healthcare professionals, the partner and peers are important sources for intervention delivery and support. In the prevention of unhealthy EBRB changes around childbirth, the involvement of both parents is needed, while health care professionals play an important role in providing personalized advice.

Determinants of Changes in Women's and Men's Physical Activity and Sedentary Behavior across the Transition to Parenthood: A Focus Group Study

BACKGROUND

Becoming a parent may cohere with drastic changes in physical activity (PA) and sedentary behavior (SB). A clear understanding of determinants of changes in PA and SB during pregnancy and postpartum is needed to facilitate the development of tailored family-based interventions.

METHODS

Thirteen focus group discussions targeting determinants of changes in PA and SB behavior were conducted, involving a total of 74 expecting and first-time parents. A semi-structured question guide was used to facilitate the discussions.

RESULTS

Four main levels of determinants were identified: the individual (including psychological, situational and biological determinants), interpersonal, environmental and policy level. Some determinants were mentioned to be a barrier (e.g., "barriers to self-care") while others were a facilitator (e.g., "weight control"). Determinants were related to both PA and SB and applicable during pregnancy as well as postpartum (e.g., "self-regulation"), or only related to one behavior and/or one period (e.g., "feeding baby"). Some were described by both parents (e.g., "parenthood perceptions"), whereas others were mentioned by women (e.g., "PA knowledge") or men (e.g., "time opportunities") only.

CONCLUSIONS

Focus should be given to interventions aimed at improving parents' self-regulation skills and support on how to cope with interpersonal and situational constraints as well as parenthood perceptions.

Serum osteocalcin levels at 4 months of age were associated with neurodevelopment at 4 years of age in term-born children

AIM

The hormone osteocalcin influenced neurodevelopment and cognition in mice models; this human study explored potential associations between total serum levels in human infants and neurodevelopment at 4 years of age.

METHODS

The data were based on two Swedish birth cohorts from 2008 to 2009. We followed 158 healthy full-term vaginal births (51% girls) by measuring serum osteocalcin in cord blood and at 4, 12 and 36 months. The values were compared with neurodevelopment tests at 4 years of age.

RESULTS

There was an association between osteocalcin at 4 months and later full-scale intelligence quotient (IQ; r² 0.031, p < 0.05). Children with osteocalcin levels in the highest quartile scored 5.6 (95% confidence interval [1.3, 9.9]) points higher than those in the lowest quartile, with mean scores of 118.8 ± 8.8 and 113.2 ± 9.2 (p < 0.05). They also scored higher on gross motor skills (p < 0.05) and showed greater ability during the drawing trail test (p < 0.005). Cord levels of osteocalcin were negatively associated with processing speed and fine motor development at 4 years, but levels at 12 and 36 months were not associated with later neurodevelopment.

CONCLUSION

Osteocalcin levels in infancy appeared to be associated with later IQ and motor development, but more research is needed.

The impact of a community-based intervention on weight, weight-related behaviours and health-related quality of life in primary school children in Victoria, Australia, according to socio-economic position

Background

Approximately a quarter of Australian children are classified as overweight or obese. In high-income countries, childhood obesity follows a socio-economic gradient, with greater prevalence amongst the most socio-economically disadvantaged children. Community-based interventions (CBI), particularly those using a systems approach, have been shown to be effective on weight and weight-related behaviours. They are also thought to have an equitable impacts, however there is limited evidence of their effectiveness in achieving this goal.

Methods

Secondary analysis was conducted on data collected from primary school children (aged 6–13 years) residing in ten communities (five intervention, five control) involved in the Whole of Systems Trial of Prevention Strategies for Childhood Obesity (WHO STOPS) cluster randomised trial in Victoria, Australia. Outcomes included Body Mass Index z-score (BMI-z) derived from measured height and weight, self-reported physical activity and dietary behaviours and health related quality of life (HRQoL). Repeat cross-sectional data from 2015 (n = 1790) and 2019 (n = 2137) were analysed, stratified by high or low socio-economic position (SEP). Multilevel linear models and generalised estimating equations were fitted to assess whether SEP modified the intervention effect on the outcomes.

Results

There were no overall changes in BMI-z for either SEP strata. For behavioural outcomes, the intervention resulted in a 22.5% (95% CI 5.1, 39.9) point greater improvement in high-SEP compared to low-SEP intervention schools for meeting physical activity guidelines. There were also positive dietary intervention effects for high SEP students, reducing takeaway and packaged snack consumption, although there was no significant difference in effect between high and low SEP students. There were positive intervention effects for HRQoL, whereby scores declined in control communities with no change in intervention communities, and this did not differ by SEP.

Conclusion

The WHO STOPS intervention had differential effects on several weight-related behaviours according to SEP, including physical activity. Similar impacts on HRQoL outcomes were found between high and low SEP groups. Importantly, the trial evaluation was not powered to detect subgroup differences. Future evaluations of CBIs should be designed with an equity lens, to understand if and how these types of interventions can benefit all community members, regardless of their social and economic resources.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12150-4.

Associations of Sleep Duration and Screen Time with Incidence of Overweight in European Children: The IDEFICS/I.Family Cohort

INTRODUCTION

Over the past decades, children have been increasingly using screen devices, while at the same time their sleep duration has decreased. Both behaviors have been associated with excess weight, and it is possible they act as mutually reinforcing behaviors for weight gain. The aim of the study was to explore independent, prospective associations of screen time and sleep duration with incident overweight in a sample of European children.

METHODS

Data from 4,285 children of the IDEFICS/I.Family cohort who were followed up from 2009/2010 to 2013/2014 were analyzed. Hours per day of screen time and of sleep duration were reported by parents at baseline. Logistic regression analyses were carried out in separate and mutually adjusted models controlled for sex, age, European country region, parental level of education, and baseline BMI z-scores.

RESULTS

Among normal weight children at baseline (N = 3,734), separate models suggest that every hour increase in screen time and every hour decrease in sleep duration were associated with higher odds of the child becoming overweight or obese at follow-up (OR = 1.16, 95% CI: 1.02-1.32 and OR = 1.23, 95% CI: 1.05-1.43, respectively). In the mutually adjusted model, both associations were attenuated slightly ( screen time OR = 1.13, 95% CI: 0.99-1.28; sleep duration OR = 1.20, 95% CI: 1.03-1.40), being consistently somewhat stronger for sleep duration.

DISCUSSION/CONCLUSION

Both screen time and sleep duration increased the incidence of overweight or obesity by 13-20%. Interventions that include an emphasis on adequate sleep and minimal screen time are needed to establish their causal role in the prevention of overweight and obesity among European children.

Pet Owners and Antibiotics: Knowledge, Opinions, Expectations, and Communication Preferences

Despite the important role of antimicrobial use in companion animals in the global challenge presented by antimicrobial resistance (AMR), very few studies have quantified pet owner factors that can contribute to suboptimal veterinary antimicrobial use. We conducted an online survey of pet owners, asking about their experiences with veterinarians, their opinions on antibiotic use and knowledge of antibiotics, and their communication preferences regarding judicious prescribing. Just over half (54%) of the 558 pet owners had received antibiotics for their pet at their last non-routine veterinary consultation and most owners were happy (83%) with the antibiotic prescribing decision of their veterinarian. A quarter (25%) indicated that they had been surprised, disappointed or frustrated when a veterinarian had not given their pet antibiotics; 15% had explicitly requested them. Owners placed a higher priority on their pet receiving the most effective treatment than on treatment being cheap or convenient. Most respondents recognized the limitations of antibiotic therapy and the risks associated with antibiotic use, but 50% believed the risks were confined to the treated animal; only a minority was aware of inter-species transfer of bacteria. Pet owners indicated that they would find judicious prescribing messages focused on the direct risks of antibiotics to their pet more compelling than those about public health. Our findings suggest that veterinary communications about responsible antibiotic use should focus on pet owners’ priorities and address or bypass their gaps in understanding regarding antibiotic resistance.

Determinants of changes in women's and men's eating behavior across the transition to parenthood: a focus group study

Background

During the pregnancy and postpartum period, both women and men experience physiological and psychological changes, which may negatively impact their eating behavior. A clear understanding of determinants of changes in eating behavior during this period is needed to facilitate the development of targeted family-based interventions countering unfavorable dietary changes during this critical life period.

Methods

Thirteen focus group discussions targeting determinants of changes in eating behavior during pregnancy and postpartum were conducted, involving a total of 74 expecting and first-time parents. A semi-structured question guide was used to facilitate the discussions. An inductive thematic approach was used to derive main and sub-categories of determinants from the data. The Determinants of Nutrition and Eating (DONE)-framework was employed to systematically organize and label the categories and determinants.

Results

Two frameworks were developed; one for the pregnancy and one for the postpartum period, comprising determinants of changes in eating behavior in both women and men. Three main levels of determinants were identified: (1) the individual level, including psychological (e.g., ‘health consciousness’), situational (e.g., ‘effort and convenience’) and biological (e.g., ‘discomfort’); (2) the interpersonal level (e.g., ‘social influence’) and (3) the environmental level, including micro- and meso/macro (e.g., ‘home/environment food availability’). Determinants acting as barriers (e.g., ‘time constraints’) or facilitators (e.g., ‘being a role model’) were identified. Many determinants were mentioned during both (e.g., ‘food knowledge’) or just one investigated period (e.g., ‘physiological changes’ during pregnancy, ‘influence of the baby’ postpartum). Finally, some were described by both parents (e.g., ‘self-regulation’), whereas others were mentioned by women (e.g., ‘(perceived) food safety’) or men (e.g., ‘other priorities’) only.

Conclusion

The developed frameworks set the foundation for the development of future family-based interventions and may be used already by healthcare providers to provide dietary guidance and support for women and men transitioning into parenthood. A focus on the interplay of individual factors at the biological and psychological level together with situational difficulties during pregnancy is recommended. Postpartum, focus should go to support first-time parents to obtain balance of both maintaining one’s own health and taking care of the baby, on improving self-regulation skills, and on coping with related situational constraints.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01137-4.

The impact of non-residential grandchild care on physical activity and sedentary behavior in people aged 50 years and over: study protocol of the Healthy Grandparenting Project

Background

Finding effective ways to support people aged > 50 years to develop adequate levels of physical activity and sedentary behavior is necessary as these behaviors are positively related to the maintenance of functional independence and health-related quality of life. Given the widespread provision of grandparental child care, examining its impact on grandparents’ energy-expenditure related behavior in the broader context of health is imperative. Therefore, the Healthy Grandparenting Project will aim to investigate the levels of physical activity and sedentary behavior, body composition and health-related quality of life in grandparents caring for their grandchildren and to compare these outcomes with non-caregiving grandparents and older adults without grandchildren, both momentarily and over time. An additional purpose is to identify possible predictors of potential changes over time.

Methods

A prospective cohort study will run over a period of 2 years, including three test occasions with a one-year time interval in between (T0 = baseline, T1 = 12 months, T2 = 24 months). A total of 276 participants will be recruited in Flanders through non-probability quota sampling (50–50% men-women), of which 92 caregiving grandparents, 92 non-caregiving grandparents and 92 non-grandparents. All three subsamples will be matched for age and sex. At each test occasion, anthropometric and body composition measurements will be determined. Participants’ levels of physical activity and sedentary behavior will be assessed both objectively and subjectively by means of accelerometry and self-report questionnaires. Information about their grandchildren and the provided grandparental care (if applicable) as well as their health-related quality of life will also be assessed using self-report questionnaires. Mixed modelling will be used to identify differences in physical activity, sedentary behavior, body composition and health-related quality of life between the subsamples at baseline, as well as to evaluate and compare changes in energy-expenditure related behavior over time between subsamples and to identify predictors of the detected changes.

Discussion

The Healthy Grandparenting Project is an innovative study examining the levels of physical activity and sedentary behavior in caregiving grandparents, non-caregiving grandparents and non-grandparents. Obtained results will help in the development of campaigns to maintain/improve health in adults at a more advanced age.

Trial registration

clinicaltrials.gov, Identifier: NTC04307589. Registered March 2020.

Nutrition- and feeding practice-related risk factors for rapid weight gain during the first year of life: a population-based birth cohort study

Background

Rapid weight gain (RWG) during infancy increases the risk of excess weight later in life. Nutrition- and feeding practices associated with RWG need to be further examined. The present study aimed to examine nutrition- and feeding practice-related risk factors for RWG during the first year of life.

Methods

A population-based longitudinal birth cohort study of 1780 infants, classified as having RWG or non-RWG during 0–3-4, 0–6 and 6–12 months. RWG was defined as a change > 0.67 in weight standard deviation scores. Associations between nutrition- and feeding practice-related factors and RWG were examined with logistic regression models.

Results

Of the participating infants, 47% had RWG during 0–3-4 months, 46% during 0–6 months and 8% during 6–12 months. In the fully adjusted models, bottle-feeding at birth and at 3–4 months and nighttime meals containing formula milk were positively associated with RWG during 0–3-4 months (p < 0.05 for all). Breastfeeding at 3–4 months and nighttime meals containing breast milk were negatively associated with RWG during this period (p < 0.001). Bottle-feeding at birth, 3–4 and 6 months and nighttime meals containing formula milk at 3–4 months were positively associated with RWG during 0–6 months (p < 0.01 for all). Breastfeeding at 3–4 and 6 months was negatively associated with RWG (p < 0.01). During 6–12 months, only bottle-feeding at 3–4 months was positively associated with RWG (p < 0.05).

Conclusions

RWG was more common during the first 6 months of life and bottle-feeding and formula milk given at night were risk factors for RWG during this period.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12887-020-02391-4.

Inverse-probability weighting and multiple imputation for evaluating selection bias in the estimation of childhood obesity prevalence using data from electronic health records

Background and objectives

Height and weight data from electronic health records are increasingly being used to estimate the prevalence of childhood obesity. Here, we aim to assess the selection bias due to missing weight and height data from electronic health records in children older than five.

Methods

Cohort study of 10,811 children born in Navarra (Spain) between 2002 and 2003, who were still living in this region by December 2016. We examined the differences between measured and non-measured children older than 5 years considering weight-associated variables (sex, rural or urban residence, family income and weight status at 2–5 yrs). These variables were used to calculate stabilized weights for inverse-probability weighting and to conduct multiple imputation for the missing data. We calculated complete data prevalence and adjusted prevalence considering the missing data using inverse-probability weighting and multiple imputation for ages 6 to 14 and group ages 6 to 9 and 10 to 14.

Results

For 6–9 years, complete data, inverse-probability weighting and multiple imputation obesity age-adjusted prevalence were 13.18% (95% CI: 12.54–13.85), 13.22% (95% CI: 12.57–13.89) and 13.02% (95% CI: 12.38–13.66) and for 10–14 years 8.61% (95% CI: 8.06–9.18), 8.62% (95% CI: 8.06–9.20) and 8.24% (95% CI: 7.70–8.78), respectively.

Conclusions

Ages at which well-child visits are scheduled and for the 6 to 9 and 10 to 14 age groups, weight status estimations are similar using complete data, multiple imputation and inverse-probability weighting. Readily available electronic health record data may be a tool to monitor the weight status in children.

Body weight, body composition and energy balance related behaviour during the transition to parenthood: study protocol of a multi-centre observational follow-up study (TRANSPARENTS)

Background

The transition to parenthood is a cornerstone event for both parents, potentially leading to relevant changes in lifestyle and behaviour. In women, the metabolic changes during and after pregnancy and the deleterious effects of excessive gestational weight gain and postpartum weight retention have been extensively described. However, there is no full understanding about which specific energy balance related behaviours (EBRB) contribute to unfavourable weight gain and weight retention. Furthermore, information on how transition to parenthood affects men is lacking. Therefore, this study aims to investigate changes in body weight, body composition and EBRB in couples transitioning to parenthood.

Methods

TRANSPARENTS is a multi-centre observational follow-up study that focuses on body weight, body composition and EBRB during the transition to parenthood. Couples (women and men) will be recruited during the first trimester of their first pregnancy. Study visits will occur at four occasions (12 weeks of pregnancy, 6 weeks postpartum, 6 months postpartum and 12 months postpartum). Anthropometrics of the parents and new-borns will be assessed including body weight, height/length, body composition (using bio-electrical impedance analysis and measurement of four skinfold thicknesses (biceps, triceps, subscapular and supraspinal/suprailiac)) and waist and hip circumference. Dietary intake, physical activity, sedentary behaviour, smoking habits, sleeping pattern, fatigue, diet and exercise related partner support, mental health, breastfeeding, contraception use, and socio-demographics will be assessed using a questionnaire. In addition, accelerometry will be used to assess physical activity and sedentary behaviour objectively. Also data from women’s medical record, such as pre-pregnancy weight and pregnancy outcomes, will be included. Multilevel modelling will be used to evaluate maternal and paternal changes in body weight, body composition and EBRB during and after pregnancy (primary outcomes). Multiple linear regression analyses will be performed to identify predictors of changes in body weight, body composition and EBRB. All analyses will be adjusted for possible confounders.

Discussion

TRANSPARENTS is a unique project identifying vulnerable parents and (un)favourable changes in EBRB throughout this potentially critical life period. Provided insights will facilitate the development of effective intervention strategies to help couples towards a healthy transition to parenthood.

Trial registration

Clinicaltrials.gov Identifier: NCT03454958. Registered March 2018.

Associations of green space metrics with health and behavior outcomes at different buffer sizes and remote sensing sensor resolutions

Satellite data is increasingly used to characterize green space for health outcome studies. Literature suggests that green space within 500 m of home is often used to represent neighborhood suitable for walking, air pollution and noise reduction, and natural healing. In this paper, we used satellite data of different spatial resolutions to derive normalized difference vegetation index (NDVI), an indicator of surface greenness, at buffer distances of 50, 100, 250 and 500 m. Data included those of 2 m spatial resolution from WorldView2, 5 m resolution from RapidEye and 30 m resolution from Landsat. We found that, after radiometric calibrations, the RapidEye and WorldView2 sensors had similar NDVI values, while Landsat imagery tended to have greater NDVI; however, these sensors showed similar vegetation distribution: locations high in vegetation cover being high in NDVI, and vice versa. We linked the green space estimates to a health survey, and identified that higher NDVI values were significantly associated with better health outcomes. We further investigated the impacts of buffer size and sensor spatial resolution on identified associations between NDVI and health outcomes. Overall, the identified health outcomes were similar across sensors of different spatial resolutions, but a mean trend was identified in bigger buffer size being associated with greater health outcome.

Parental education and family income affect birthweight, early longitudinal growth and body mass index development differently

AIM

This study investigated the effects of two parental socio-economic characteristics, education and income, on growth and risk of obesity in children from birth to 8 years of age.

METHODS

Longitudinal growth data and national register-based information on socio-economic characteristics were available for 3,030 Swedish children. The development of body mass index (BMI) and height was compared in groups dichotomised by parental education and income.

RESULTS

Low parental education was associated with a higher BMI from 4 years of age, independent of income, immigrant background, maternal BMI and smoking during pregnancy. Low family income was associated with a lower birthweight, but did not independently predict BMI development. At 8 years of age, children from less educated families had a three times higher risk of obesity, independent of parental income. Children whose parents had fewer years of education but high income had significantly higher height than all other children.

CONCLUSION

Parental education protected against childhood obesity, even after adjusting for income and other important parental characteristics. Income-related differences in height, despite similar BMIs, raise questions about body composition and metabolic risk profiles. The dominant role of education underscores the value of health literacy initiatives for the parents of young children.

Parents with overweight children two and five years of age did not perceive them as weighing too much

AIM

This study examined whether the parents of children who were overweight at two and five years of age perceived their children as being too heavy and related the findings to sociodemographic factors.

METHODS

The data collection included parental questionnaires and anthropometric data from a longitudinal birth cohort of 2666 children born in the south-west region of Sweden in 2007-2008.

RESULTS

We found that 14.9 and 11.8% of the children were considered overweight or obese at the age of two and five, but 96.4 and 87.1% of their parents perceived their weight to be just about right at these ages. The difference was statistically significant (p < 0.001). Parents who were overweight themselves and had a low educational level were associated with a higher probability of misperception: at two years of age, the odds ratio was 2.75 (95% confidence interval 1.80-4.21), and at the age of five, it was 1.92 (1.24-2.97).

CONCLUSION

Most parents did not perceive that their overweight children weighed too much, but their judgement improved as the child got older. Parents who were overweight or had a low educational level were more likely to misperceive their child's weight. Health Care professionals need to be aware of this gap in perception.

Attrition in the European Child Cohort IDEFICS/I.Family: Exploring Associations Between Attrition and Body Mass Index

Attrition may lead to bias in epidemiological cohorts, since participants who are healthier and have a higher social position are less likely to drop out. We investigated possible selection effects regarding key exposures and outcomes in the IDEFICS/I.Family study, a large European cohort on the etiology of overweight, obesity and related disorders during childhood and adulthood. We applied multilevel logistic regression to investigate associations of attrition with sociodemographic variables, weight status, and study compliance and assessed attrition across time regarding children's weight status and variations of attrition across participating countries. We investigated selection effects with regard to social position, adherence to key messages concerning a healthy lifestyle, and children's weight status. Attrition was associated with a higher weight status of children, lower children's study compliance, older age, lower parental education, and parent's migration background, consistent across time and participating countries. Although overweight (odds ratio 1.17, 99% confidence interval 1.05-1.29) or obese children (odds ratio 1.18, 99% confidence interval 1.03-1.36) were more prone to drop-out, attrition only seemed to slightly distort the distribution of children's BMI at the upper tail. Restricting the sample to subgroups with different attrition characteristics only marginally affected exposure-outcome associations. Our results suggest that IDEFICS/I.Family provides valid estimates of relations between socio-economic position, health-related behaviors, and weight status.

[Evaluation, correction and impact of non-response in studies of childhood obesity]

OBJECTIVE

To evaluate and correct the impact of non-response in the prevalence of underweight, overweight and obesity in children aged 6 to 15 years old using silhouette scales.

METHOD

Cross-sectional study carried out in 2013 among 8,145 Galician schoolchildren aged 6-15 years old. The students who agreed to participate were weighed and measured and, based on body mass index, the prevalence of underweight, overweight and obesity was estimated. Teachers rated all students using silhouette scales. The valuations were used to estimate the prevalence corrected by non-response. Using the Bayes theorem, participation rates were estimated according to weight status.

RESULTS

The participation rate was 92.3% in the 6 -to 11-year-old group, and 90% in the 12- to 15-year old age group. In both groups, the prevalence of underweight and overweight were similar between participants and non-participants. However, obesity was higher among non-participants, especially at 12 to 15 years of age (6.3% vs. 12.2% ; p < 0.05). The prevalence did not change when corrected by the teacher's valuation. The participation rate of obese students was lower than the overall rate (82% vs. 90% at 12 to 15 years old; p < 0.05).

CONCLUSIONS

The presence of participation bias, which was greater at 12-15 years old, was confirmed. However, the impact of the bias on prevalence was negligible due to the high participation rate. In obesity studies with objective measures, it is essential to quantify non-participation, as well as to assess its impact and correct it.

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 (β=0·050; 95 % CI 0·006, 0·093), increased waist circumference (β=0·071; 95 % CI 0·001, 0·141) and increased fat mass gain (β=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 (β=0·079; 95 % CI 0·015, 0·143), increased waist circumference (β=0·172; 95 % CI 0·069, 0·275) and increased fat mass gain (β=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.

Early Life Factors and Inter-Country Heterogeneity in BMI Growth Trajectories of European Children: The IDEFICS Study

BACKGROUND

Starting from birth, this explorative study aimed to investigate between-country differences in body mass index (BMI) trajectories and whether early life factors explain these differences.

METHODS

The sample included 7,644 children from seven European countries (Belgium, Cyprus, Germany, Hungary, Italy, Spain, Sweden) participating in the multi-centre IDEFICS study. Information on early life factors and in total 53,409 repeated measurements of height and weight from 0 to <12 years of age were collected during the baseline (2007/2008) and follow-up examination (2009/2010) supplemented by records of routine child health visits. Country-specific BMI growth curves were estimated using fractional polynomial mixed effects models. Several covariates focussing on early life factors were added to the models to investigate their role in the between-countries differences.

RESULTS

Large between-country differences were observed with Italian children showing significantly higher mean BMI values at all ages ≥ 3 years compared to the other countries. For instance, at age 11 years mean BMI values in Italian boys and girls were 22.3 [21.9;22.8; 99% confidence interval] and 22.0 [21.5;22.4], respectively, compared to a range of 18.4 [18.1;18.8] to 20.3 [19.8;20.7] in boys and 18.2 [17.8;18.6] to 20.3 [19.8;20.7] in girls in the other countries. After adjustment for early life factors, differences between country-specific BMI curves became smaller. Maternal BMI was the factor being most strongly associated with BMI growth (p<0.01 in all countries) with associations increasing during childhood. Gestational weight gain (GWG) was weakly associated with BMI at birth in all countries. In some countries, positive associations between BMI growth and children not being breastfed, mothers' smoking during pregnancy and low educational level of parents were found.

CONCLUSION

Early life factors seem to explain only some of the inter-country variation in growth. Maternal BMI showed the strongest association with children's BMI growth.

Impact of a community based health-promotion programme in 2- to 9-year-old children in Europe on markers of the metabolic syndrome, the IDEFICS study

INTRODUCTION

One objective of 'Identification and prevention of Dietary-and lifestyle-induced health EFfects In Children and infantS', the IDEFICS study, was to implement a community-oriented childhood obesity prevention intervention in eight European countries.

OBJECTIVE

To assess the effect of an obesity primary prevention programme on metabolic markers.

METHODS

The study had a non-randomized cluster-experimental design. In each country, children were recruited from distinct communities serving as intervention and control regions. Health examinations were done during 2007-2008 before the intervention (T0 ) and during 2009-2010 (T1 ). Children with results available from T0 and T1 on blood pressure, waist circumference and at least one blood-marker (fasting glucose, insulin, HOMA-IR, HbA1c, HDL- and LDL-cholesterol, triglycerides, C-reactive protein) were included. A metabolic syndrome (MetS) score was calculated.

RESULTS

A total of 7,406 children (age 2-9.9 years) of the 16,228 participating at T0 provided the necessary data. No effect of the intervention was seen on insulin, HOMA-IR, CRP or the MetS score. Overall fasting glucose increased less in the intervention than in the control region, a pattern driven by three of the eight countries and more pronounced in children of parents with low education. Overall, HbA1c and waist circumference increased more and blood pressure less in the intervention regions.

CONCLUSION

We observed no convincing effect of the intervention on markers of the metabolic syndrome. We identified diverse patterns of change for several markers of uncertain relation to the intervention.

Behavioural effects of a community-oriented setting-based intervention for prevention of childhood obesity in eight European countries. Main results from the IDEFICS study

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.

Are context-specific measures of parental-reported physical activity and sedentary behaviour associated with accelerometer data in 2-9-year-old European children?

OBJECTIVE

The aim of the present study was to investigate if context-specific measures of parental-reported physical activity and sedentary behaviour are associated with objectively measured physical activity and sedentary time in children.

DESIGN

Cross-sectional study.

SETTING

Seven European countries taking part in the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-induced Health Effects in Children and Infants) study.

SUBJECTS

Data were analysed from 2-9-year-old children (n 5982) who provided both parental-reported and accelerometer-derived physical activity/sedentary behaviour measures. Parents reported their children's daily screen-time, weekly sports participation and daily outdoor playtime by means of the Outdoor Playtime Checklist (OPC) and Outdoor Playtime Recall Questions (OPRQ).

RESULTS

Sports participation, OPC- and OPRQ-derived outdoor play were positively associated with accelerometer-derived physical activity. Television viewing and computer use were positively associated with accelerometer-derived sedentary time. All parental-reported measures that were significantly associated with accelerometer outcomes explained only a minor part of the variance in accelerometer-derived physical activity or sedentary time.

CONCLUSIONS

Parental-reported measures of physical activity and sedentary behaviour are not useful as a proxy for 2-9-year-old children's physical activity and sedentary time. Findings do not preclude the use of context-specific measures but imply that conclusions should be limited to the context-specific behaviours that are actually measured. Depending on the aim of the study, future research should carefully consider the choice of measurements, including the use of subjective or objective measures of the behaviour of interest or a combination of both.

Usual energy and macronutrient intakes in 2-9-year-old European children

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.

European children's sugar intake on weekdays versus weekends: the IDEFICS study

OBJECTIVES

To compare the intake of total sugars, foods and drinks rich in added sugar, and energy in children on weekdays (Monday-Thursday), Fridays and weekends.

METHODS

Dietary intake (g, kJ, energy %) was assessed using a computerized 24-h recall method in a sample of 2- to 9-year-old children from Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden who were participating in the IDEFICS baseline study (2007-2008). Analyses were performed in 9497 children by selecting one 24-h recall per child (for comparison of weekdays vs weekends, and Fridays vs weekdays and weekends). Selected stratified analyses were performed by country and age group.

RESULTS

Intake of total sugars exceeded 20 energy % in all countries but one. In the non-stratified analyses, the intakes of total sugars and foods and drinks rich in added sugar were found to be higher on weekends compared with weekdays (both P<0.001), and intakes on Fridays were a mix between intakes on weekdays and weekends. Energy intake did not differ between weekdays and weekends. RESULTS were somewhat heterogeneous, both across countries and age groups.

CONCLUSIONS

High intake of sugar remains an important nutritional problem in children of many European countries. Interventions aiming to prevent this diet pattern may optimize their impact by targeting dietary habits on Fridays and weekends. Furthermore, when conducting dietary assessment in children, data from weekends and Fridays in combination with a selection of Mondays to Thursdays are needed to capture habitual sugar intake. Age and dietary cultures should also be considered in dietary intervention and assessment as effect modifications were seen for both age and country.

Parental marital status and childhood overweight and obesity in Norway: a nationally representative cross-sectional study

OBJECTIVE

Sociodemographic changes in Norway and other western industrialised countries, including family structure and an increasing proportion of cohabiting and divorced parents, might affect the prevalence of childhood overweight and obesity issues. We aimed to examine whether parental marital status was associated with general and abdominal obesity among children. We also sought to explore whether the associations differed by gender.

DESIGN

Cross-sectional.

SETTING

127 primary schools across Norway.

PARTICIPANT

3166 third graders (mean age 8.3 years) participating in the nationally representative Norwegian Child Growth Study in 2010.

MEASUREMENTS

Height, weight and waist circumference were objectively measured. The main outcome measures were general overweight (including obesity; body mass index ≥25 kg/m(2)) using International Obesity Task Force (IOTF) cut-offs and abdominal obesity (waist-to-height ratio ≥0.5) by gender and parental marital status. Prevalence ratios, adjusted for possible confounders, were calculated by log-binomial regression.

RESULTS

General overweight (including obesity) was 1.54 (95% CI 1.21 to 1.95) times more prevalent among children of divorced parents compared with children of married parents, and the corresponding prevalence ratio for abdominal obesity was 1.89 (95% CI 1.35 to 2.65). Formal tests of the interaction term parental marital status by gender were not statistically significant. However, in gender-specific analyses the association between parental marital status and adiposity measures was only statistically significant in boys (p=0.04 for general overweight (including obesity) and p=0.01 for abdominal obesity). The estimates were robust against adjustment for maternal education, family country background and current area of residence.

CONCLUSIONS

General and abdominal obesities were more prevalent among children of divorced parents. This study provides valuable information by focusing on societal changes in order to identify vulnerable groups.

Barriers to and facilitators of nurse-parent interaction intended to promote healthy weight gain and prevent childhood obesity at Swedish child health centers

BACKGROUND

Overweight and obesity in preschool children have increased worldwide in the past two to three decades. Child Health Centers provide a key setting for monitoring growth in preschool children and preventing childhood obesity.

METHODS

We conducted semi-structured interviews with 15 nurses working at Child Health Centers in southwest Sweden in 2011 and 2012. All interviews were tape recorded and transcribed verbatim and imported to QSR N'Vivo 9 software. Data were analyzed deductively according to predefined themes using content analysis.

RESULTS

Findings resulted in 332 codes, 16 subthemes and six main themes. The subthemes identified and described barriers and facilitators for the prevention of childhood obesity at Child Health Centers. Main themes included assessment of child's weight status, the initiative, a sensitive topic, parental responses, actions and lifestyle patterns. Although a body mass index (BMI) chart facilitated greater recognition of a child's deviant weight status than the traditional weight-for-height chart, nurses used it inconsistently. Obesity was a sensitive topic. For the most part, nurses initiated discussions of a child's overweight or obesity.

CONCLUSION

CHCs in Sweden provide a favorable opportunity to prevent childhood obesity because of a systematic organization, which by default conducts growth measurements at all health visits. The BMI chart yields greater recognition of overweight and obesity in children and facilitates prevention of obesity. In addition, visualization and explanation of the BMI chart helps nurses as they communicate with parents about a child's weight status. On the other hand, inconsistent use and lack of quality assurance regarding the recommended BMI chart was a barrier to prevention, possibly delaying identification of overweight or obesity. Other barriers included emotional difficulties in raising the issue of obesity because it was perceived as a sensitive topic. Some parents deliberately wanted overweight children, which was another specific barrier. Concerned parents who took the initiative or responded positively to the information about obesity facilitated prevention activities.