Self-Reported Body Weight and Height: An Assessment Tool for Identifying Children with Overweight/Obesity Status and Cardiometabolic Risk Factors Clustering

Accuracy of Parent-Measured Weight and Height of Preschool Children at Home With Increasing Levels of Instruction

Background: The purpose of this study was to determine how accurately parents measure their preschool child's weight and height with increasing levels of instruction. Methods: Parents measured their child's (n = 30 dyads) weight (own weight scale) and height (soft tape measure) using three levels of instruction: instructional guide (level 1); guide, demonstration video (level 2); and guide, video, and virtual monitoring (level 3), which were compared to researcher measurements (electronic weight scale, Stadiometer). Paired t-tests were used to determine differences between researcher and parent measurements and between the three parent levels. Inaccurate classifications were calculated using parent-measured values for the four categories (underweight, healthy, overweight, obese). Results: Raw mean parent-measured weights (17.4 ± 2.3 kg) differed from researcher by 0.2 kg (level 1), 0.3 kg (level 2), and 0.1 kg (level 3). Raw mean parent-measured heights (104.0 ± 5.9 cm) differed from researcher by 0.9 cm (level 1, p = 0.005), 0.4 cm (level 2, NS), and 0.3 cm (level 3, NS). Across all levels, 48.9% and 65.5% parents overmeasured their children's weights and heights, respectively. Using parent-measured values, 29.4% of children were classified high while 70.5% were classified low. Parents were more likely to make errors if their children were on the borderline between any of the two weight categories. Conclusion: Findings indicate that an instructional guide with demonstration video is helpful in improving the parents' accuracy of their children's weights and heights. More research is needed to determine accuracy in population other than White parents with high education levels and children under overweight and obese category.

Parent-Child Associations in Accelerometer-Measured Physical Activity and Sedentary Behaviour: The FAMIPASS Study

Parent-child patterns in objectively measured movement behaviours were the highlight of this study. A total of 381 families (337 mothers, 256 fathers, 190 daughters, and 191 sons) from 36 randomly selected schools and kindergartens provided valid accelerometer data. Sedentary behaviour and physical activity (PA) were assessed using ActiGraph accelerometers. Spearman's rho was used to evaluate parent-child associations, while logistic regression analysis (the backward LR method) was used to recognize factors related to children's achievement of PA recommendations. Results indicated that girls engaged more in light PA, while boys showed higher levels of moderate and vigorous PA. Mothers spent less time sitting and more time in light PA compared to fathers, resulting in higher total PA levels. Father-son pairs showed a stronger association in total PA than mother-son pairs. Children aged 6-10 years and those with mothers who engaged in more vigorous PA were more likely to meet PA recommendations compared to younger children and those with less active mothers.

Reliability of Self-Reported Height and Weight in Children: A School-Based Cross-Sectional Study and a Review

Since anthropometric measurements are not always feasible in large surveys, self-reported values are an alternative. Our objective was to assess the reliability of self-reported weight and height values compared to measured values in children with (1) a cross-sectional study in Switzerland and (2) a comprehensive review with a meta-analysis. We conducted a secondary analysis of data from a school-based study in Switzerland of 2616 children and a review of 63 published studies including 122,629 children. In the cross-sectional study, self-reported and measured values were highly correlated (weight: r = 0.96; height: r = 0.92; body mass index (BMI) r = 0.88), although self-reported values tended to underestimate measured values (weight: -1.4 kg; height: -0.9 cm; BMI: -0.4 kg/m2). Prevalence of underweight was overestimated and prevalence of overweight was underestimated using self-reported values. In the meta-analysis, high correlations were found between self-reported and measured values (weight: r = 0.94; height: r = 0.87; BMI: r = 0.88). Weight (-1.4 kg) and BMI (-0.7 kg/m2) were underestimated, and height was slightly overestimated (+0.1 cm) with self-reported values. Self-reported values tended to be more reliable in children above 11 years old. Self-reported weight and height in children can be a reliable alternative to measurements, but should be used with caution to estimate over- or underweight prevalence.

Parental practices, body dissatisfaction and weight control practices in female adolescents from public schools in southern Brazil

The objective was to verify the association between body dissatisfaction (BD) - constituted by the desire to lose weight - with family and personal aspects related to the shape of the body and weight control practices in female adolescents. A cross-sectional, observational epidemiological study with adolescents aged 12-19 years, enrolled in classes of the 8th and 9th years of public schools belonging to the urban area of the city of Caxias do Sul/Rio Grande do Sul, Brazil, was conducted. A self-applicable questionnaire was used. BD was assessed using a silhouette scale. Multivariate regression was performed using Poisson regression with robust variation, hierarchically using a pre-established conceptual model, using the prevalence ratio (PR) adjusted with 95 % CI as a measure of effect. A significance level of 5 % (P ≤ 0·05) was considered. Among the 685 female students, 77·2 % had BD. The father's incentive to diet sometimes (PR 1·19; 95 % CI 1·07, 1·32; P ≤ 0·001) and always (PR 1·15; 95 % CI 1·03, 1·28; P ≤ 0·001), trying to lose weight (PR 1·63; 95 % CI 1·33, 1·99; P ≤ 0·001), dieting five times or more (PR 1·22; 95 % CI 1·09, 1·36; P ≤ 0·001) and skipping meals less than once a week (PR 1·16; 95 % CI 1·04, 1·29; P = 0·026) increased the chances of having BD. In conclusion, among the investigated parents' behaviours, only the father's incentive to go on a diet was associated with BD. Adolescent weight control practices increased the chances of having BD. Thus, it facilitates the identification of this condition at an early stage, enabling adequate treatment and prevention of health complications.

Weekday-Weekend Sedentary Behavior and Recreational Screen Time Patterns in Families with Preschoolers, Schoolchildren, and Adolescents: Cross-Sectional Three Cohort Study

Background: Excessive recreational screen time (RST) has been associated with negative health consequences already being apparent in preschoolers. Therefore, the aim of this study was to reveal parent-child sedentary behavior, and RST patterns and associations with respect to the gender, age category of children, and days of the week. Methods: Our cross-sectional survey included 1175 parent-child dyads with proxy-reported RST data collected during a regular school week during the spring and fall between 2013 and 2019. The parent-child RST (age and RST) relationship was quantified using Pearson’s (r_P) correlation coefficient. Results: Weekends were characterized by longer RST for all family members (daughters/sons: +34/+33 min/day, mothers/fathers: +43/+14 min/day) and closer parent-child RST associations than on weekdays. The increasing age of children was positively associated with an increase in RST on weekdays (+6.4/+7.2 min per year of age of the daughter/son) and weekends (+5.8/+7.5 min per year of age of the daughter/son). Conclusions: Weekends provide a suitable target for implementation of programs aimed at reducing excessive RST involving not only children, but preferably parent-child dyads.

Adolescent sleep characteristics and body-mass index in the Family Life, Activity, Sun, Health, and Eating (FLASHE) Study

Sleep may play a role in overweight and obesity in adolescents. The objective of this study is to investigate the relationships between sleep duration and timing and overweight and obesity status in adolescents, with a special emphasis on weekday-weekend difference in sleep characteristics as well as sex-specific relationships. We examined 1,254 U.S. adolescents (12-17 years) self-reported sleep duration, timing, weekday-weekend differences in duration and timing in relation to overweight and obesity. We found an inverse association between sleep duration and overweight and obesity. Compared to 8-9 h of sleep, short sleep (< 7 h) on weekdays was associated with higher odds of overweight and obesity [Odds ratio (95% confidence interval), 1.73 (1.00, 2.97)] in the overall population, while long sleep (10+ h) on weekends was associated with lower odds, but only in males [0.56 (0.34, 0.92)]. We also found that a larger weekday-weekend difference in sleep duration was associated with overweight and obesity in females, but not in males. Specifically, the odds of overweight and obesity were significantly higher among females reporting longer sleep on weekends than weekdays by ≥ 2 h [2.31 (1.15, 4.63)] when compared to those reporting little weekday-weekend differences. Sleep timing, or weekday-weekend differences in sleep timing, were not associated with overweight and obesity in the overall population, although we found suggestive evidence linking later weekend sleep with overweight and obesity in females. Our findings support a role of sleep in adolescent obesity and suggest sex-differences in this relationship that warrant future studies.

The Relationship between Weight Status, Health-Related Quality of Life, and Life Satisfaction in a Sample of Spanish Adolescents

Excess weight has been associated with numerous psychosocial problems and is considered to be one of the most important health problems of today. The aim of this study is to analyze the relationship between weight status, which is evaluated by means of the body mass index (BMI), and the health-related quality of life (HRQoL) and life satisfaction (LS) variables in Spanish adolescents, as well as to examine whether gender influences this interrelationship. A total of 1197 subjects studying in their 1st and 4th years of high school (mean age: 14.4 years, SD: 1.69) participated in the study by completing the Health Behavior in School-Aged Children (HBSC) questionnaire. Then, the participants were grouped into the following categories: underweight, normal weight, overweight, and obese. The results show that boys have significantly higher HRQoL as well as higher levels of LS. On the other hand, only the obese group shows significantly lower scores in both HRQoL and LS than those in the normal-weight group. The interaction of weight category and gender does not have a significant impact on the variables that have been analyzed (HRQoL or LS).

Time-trends and correlates of obesity in Czech adolescents in relation to family socioeconomic status over a 16-year study period (2002-2018)

Background

The main objective of the study is to analyse the changes in the prevalence of obesity among Czech adolescents between 2002 and 2018 with regard to the socioeconomic status (SES) of adolescents’ families and to find SES-separated correlates of adolescents’ obesity in 2018.

Methods

A nationally representative sample of 29,879 adolescents (49.6% of them boys) aged 10.5–16.5 years was drawn from the Health Behaviour in School-aged Children cross-sectional, self-reported questionnaire surveys conducted in 2002, 2006, 2010, 2014, and 2018 in Czechia. Chi-square (χ²) tests were performed to assess the changes in the prevalence of obesity in both genders and all SES categories of adolescents between 2002 and 2018, and SES category-related differences in the prevalence of obesity in 2018 separately for boys and girls. A series of multiple stepwise logistic regression (backward elimination) analyses were used to reveal obesity correlates separately for SES categories of adolescents.

Results

Across the quadrennial surveys from 2002 to 2018, we observed a clear increase in the prevalence of obesity in all SES categories of adolescents, which was most striking (p < 0.05) in adolescents with low SES (boys: + 7.5% points (p.p.); girls + 2.4 p.p.). When all the survey cycles were compared, the highest prevalence of obesity was evident in the low-SES adolescents in 2018, both in girls (5.1%) and boys (12.0%). Regardless of the adolescent SES category, the lower odds of obesity were significantly (p < 0.05) associated with regular vigorous physical activity (PA), participation in organized sport, and daily consumption of sweets. In addition, at least 60 min of moderate-to-vigorous PA significantly reduced the odds of obesity in adolescents of low and high SES categories.

Conclusions

An unreasonable increase in the prevalence of obesity in adolescents with low SES highlights the need to prevent obesity in adolescents with a low-SES background. Additionally, significantly higher odds of obesity in 11- and 13-year-old adolescents from low-SES families, compared with their peers aged 15, indicated an expectable rise in obesity in older low-SES adolescents in the near future.

Change in overweight and obesity over a decade according to sociodemographic factors in Brazilian adolescents

The aims were to examine changes in the prevalence of overweight and obesity among students from 2001 to 2011, and to verify if these changes differ according to age group, area of residence, and family income. We analyzed two cross-sectional surveys conducted in 2001 and 2011 with brazilian adolescents. Sociodemographic and anthropometric characteristics were self-reported using a questionnaire. Multinomial logistic regression was used to analyze changes in overweight and obesity between the two surveys. The nutritional status was the outcome of the present study and the surveys (2001 and 2011) were the exposure. The odds of being overweight and obese were higher among boys and girls in urban areas in the 2011 survey compared to the 2001. Boys and girls with higher income were also more likely to present overweight and obesity in the second survey compared to the first. An increase of overweight and obesity was observed over a decade. We suggest that future interventions consider the area of residence and the family income to strengthen the effectiveness of actions developed to prevent and control these indicators among adolescents.

The Relative Impacts of Sibling Relationships on Adolescent Body Perceptions

The sibling relationship is the longest relationship of the life course and has been found to influence youth adjustment (Dunn, 2002 ). Given that adolescence is a time of increased body awareness, the authors examined the potential role of siblings' body conceptions and sibling relationship quality on adolescent body conceptions. In a sample of 101 predominantly White, middle-class adolescent sibling dyads, the authors found that positive sibling relationship quality was associated with higher physical self-worth in adolescents, but that this differed by sibling gender and sibling physical self-worth. Alternatively, negative sibling relationship quality was associated with lower physical self-worth for adolescents, but differed based on birth order, sibling physical self-worth, and adolescent gender.

Health-related parental indicators and their association with healthy weight and overweight/obese children's physical activity

Background

Although it is accepted that parents play a key role in forming children’s health behaviours, differences in parent-child physical activity (PA) have not previously been analysed simultaneously in random samples of families with non-overweight and overweight to obese preschool and school-aged children. This study answers the question which of the health-related parental indicators (daily step count (SC), screen time (ST), and weight status and participation in organized leisure-time PA) help their children achieve the step count recommendations.

Methods

A nationally representative sample comprising 834 families including 1564 parent-child dyads who wore the Yamax Digiwalker SW-200 pedometer for at least 8 h a day on at least four weekdays and both weekend days and completed a family log book (anthropometric parameters, SC, and ST). Logistic regression analyses were used to investigate whether parental achievement of the daily SC recommendation (10,000 SC/day), non-excessive ST (< 2 h/day), weight status, and active participation in organized PA were associated with children’s achievement of their daily SC (11,500 SC/day for pre-schoolers and 13,000/11,000 SC/day for school-aged boys/girls).

Results

While living in a family with non-overweight parents helps children achieve the daily SC recommendation (mothers in the model: OR = 3.50, 95% CI = 2.29–5.34, p < 0.001; fathers in the model: OR = 2.41, 95% CI = 1.37–4.26, p < 0.01) regardless of their age category, gender, or ST, for families with overweight/obese children, only the mother’s achievement of the SC recommendations and non-excessive ST significantly (p < 0.05) increase the odds of their children reaching the daily SC recommendation. The active participation of children in organized leisure-time PA increases the odds of all children achieving the daily SC recommendations (OR = 1.80–2.85); however, for overweight/obese children this remains non-significant. The participation of parents in organized leisure-time PA does not have a significant relationship to the odds of their overweight/obese or non-overweight children achieving the daily SC recommendations.

Conclusions

The mother’s health-related behaviours (PA and ST) significantly affect the level of PA of overweight/obese preschool and school-aged children. PA enhancement programmes for overweight/obese children cannot rely solely on the active participation of children in organized leisure-time PA; they also need to take other family-based PA, especially at weekends, into account.

Weekday-weekend variations in mother-/father-child physical activity and screen time relationship: A cross-sectional study in a random sample of Czech families with 5- to 12-year-old children

This study assessed the associations between these factors in a random sample of Czech families with preschool and school-aged children. A nationally representative sample comprised 185 families with preschool children and 649 families with school-aged children (dyads; both parents and child n = 365, mother and child n = 730, and father and child n = 469). The participants wore Yamax Digiwalker SW-200 pedometers at least four weekdays and both weekend days and completed family logbooks (anthropometric parameters, daily step counts (SC), and screen time (ST)). When a parent (fathers at weekends and mothers both on weekdays and at weekends) achieved 10,000 SC per day, their children were also significantly (OR = 2.93-6.06, 95% CI = 2.02-9.26) more likely to meet the daily SC recommendation. On the contrary, the involvement of fathers in organized leisure-time PA reduced their children's odds of meeting the SC recommendation on weekdays (OR = 0.53, 95% CI = 0.31-0.89) and at weekends (OR = 0.41, 95% CI = 0.24-0.72). The excessive ST of parents at weekends reduced the odds of their children meeting the SC recommendation (mother-child dyads: OR = 0.44, 95% CI = 0.26-0.72; father-child dyads: OR = 0.63, 95% CI = 0.37-1.06). High levels of parents' PA contribute to the achievement of the recommended daily PA in children on weekdays and at weekends. Excessive weekend ST of parents reduces their odds of their children achieving the recommended daily PA; however, the influence of parents' PA on their children's achieving the recommended daily PA is stronger than the inhibitory effect of ST.

How accurate is the prevalence of overweight and obesity in children and adolescents derived from self-reported data? A meta-analysis

OBJECTIVE

The aim of the current meta-analysis was to evaluate the accuracy of using BMI based on self-reported height and weight (BMIsr) to estimate the prevalence of overweight and obesity among children and adolescents.

DESIGN

A systematic literature search was conducted to select studies that compared the prevalence rates of overweight and obesity based on BMIsr and BMIm (BMI based on measured height and weight). A random-effect model was assumed to estimate summary prevalence rates and prevalence ratio (PR).

RESULTS

Thirty-seven studies were included. The aggregated prevalence of overweight and obesity based on BMIsr (0·190, 95 % CI 0·163, 0·221) was significantly lower than that based on BMIm (0·233, 95 % CI 0·203, 0·265). The pooled mean PR was 0·823 (95 % CI 0·775, 0·875). Moderator analyses showed that the underestimation was related to gender, age, weight status screened (overweight v. obesity) and weight status screening tool.

CONCLUSIONS

BMIsr may produce less biased results under some conditions than others. Future researchers using BMIsr may consider these findings and avoid the conditions that could lead to more severe underestimation of the prevalence of overweight and obesity among children and adolescents.

Trends and correlates of overweight/obesity in Czech adolescents in relation to family socioeconomic status over a 12-year study period (2002-2014)

Background

This study examined a) trends in overweight/obesity, moderate-to-vigorous physical activity (MVPA), and screen time (ST) among Czech adolescents over a 12-year study period (2002–2014) in relation to family affluence (FA) and b) correlates of adolescent overweight/obesity from different FA categories.

Methods

A nationally representative sample of 18,250 adolescents (51.4% girls) aged 10.5–16.5 years was drawn from the Czech Health Behaviour in School-aged Children questionnaire-based surveys in 2002, 2006, 2010, and 2014. Using the FA scale, the socioeconomic status (SES) of the respondents’ families was assessed. SES-stratified trends in the prevalence of overweight/obesity meeting the MVPA (≥60 min/day), and ST (≤2 h/day) recommendations were assessed using logistic regression.

Results

A trend-related significant increase (p < 0.05) in the prevalence of overweight/obesity was observed in low−/medium-FA boys and medium−/high-FA girls. Unlike in high-FA adolescents, a significant decrease was revealed in the rates of meeting the MVPA recommendation in low-FA boys (28.9%₂₀₀₂ → 23.3%₂₀₁₄, OR = 0.75, 95% CI = 0.59–0.95, p < 0.05) and girls (22.3%₂₀₀₂ → 17.3%₂₀₁₄, OR = 0.73, 95% CI = 0.57–0.92, p < 0.01). A significant (p < 0.001) trend-related increase in excessive ST was evident in adolescents regardless of gender and FA category. Generally, girls and older adolescents had lower odds of overweight/obesity than boys and 11-year-old adolescents. While in the high-FA category of adolescents, achieving 60 min of MVPA daily and the absence of excessive ST on weekdays significantly (p < 0.01) reduced their odds of being overweight/obese, in low-FA adolescents this was not the case.

Conclusions

High rates of overweight/obesity and a poor level of daily MVPA among low-FA children provide disturbing evidence highlighting the necessity of public health efforts to implement obesity reduction interventions for this disadvantaged population.

Consistency evaluation of values of weight, height, and body mass index in Food Intake and Physical Activity of School Children: the quality control of data entry in the computerized system

INTRODUCTION

The quality control of data entry in computerized questionnaires is an important step in the validation of new instruments. The study assessed the consistency of recorded weight and height on the Food Intake and Physical Activity of School Children (Web-CAAFE) between repeated measures and against directly measured data.

METHODS

Students from the 2nd to the 5th grade (n = 390) had their weight and height directly measured and then filled out the Web-CAAFE. A subsample (n = 92) filled out the Web-CAAFE twice, three hours apart. The analysis included hierarchical linear regression, mixed linear regression model, to evaluate the bias, and intraclass correlation coefficient (ICC), to assess consistency. Univariate linear regression assessed the effect of gender, reading/writing performance, and computer/internet use and possession on residuals of fixed and random effects.

RESULTS

The Web-CAAFE showed high values of ICC between repeated measures (body weight = 0.996, height = 0.937, body mass index - BMI = 0.972), and regarding the checked measures (body weight = 0.962, height = 0.882, BMI = 0.828). The difference between means of body weight, height, and BMI directly measured and recorded was 208 g, -2 mm, and 0.238 kg/m², respectively, indicating slight BMI underestimation due to underestimation of weight and overestimation of height. This trend was related to body weight and age.

CONCLUSION

Height and weight data entered in the Web-CAAFE by children were highly correlated with direct measurements and with the repeated entry. The bias found was similar to validation studies of self-reported weight and height in comparison to direct measurements.

Accuracy of using self-reported data to screen children and adolescents for overweight and obesity status: A diagnostic meta-analysis

OBJECTIVE

To estimate the accuracy of using the self-reported body mass index (BMIsr) for screening children and adolescents for overweight and obesity status by quantitatively synthesizing individual studies in the research literature.

METHOD

Three databases, namely PubMed, Web of Science, and EBSCOhost were searched up to September 2016. Studies were included that collected both the self-reported data (BMIsr) and direct measurement data (i.e., BMI based on measured height and weight, BMIm) to screen children and adolescents for overweight and obesity status, and provided sufficient data on sensitivity and specificity. Sensitivity, specificity, likelihood ratios, and diagnostic odds ratios from each of the included studies were pooled by using a random-effects meta-analytic model, and summary receiver operating characteristic curve (ROC) was also constructed.

RESULTS

Twenty-three studies were identified. For screening children and adolescents with overweight and obesity, the use of BMIsr presented a pooled sensitivity of 0.76 (95% CI, 0.76-0.77), a pooled specificity of 0.96 (95% CI, 0.96-0.97) and a pooled DOR of 92.4 (95% CI: 74.3-114.8). Moderator analyses showed that the sample regions (America vs. Europe vs. Asia), weight status screening references (IOTF vs. CDC vs. Nation-specific standard) and weight status screened (overweight vs. obesity) had contributed to the inconsistent findings concerning the screening accuracy across the studies.

CONCLUSIONS

Based on the results of current meta-analysis, the use of BMIsr has good overall performance with moderate sensitivity and high specificity, and it is a viable alternative when direct measurement of BMI is not available.

Parent-Child Relationship of Pedometer-Assessed Physical Activity and Proxy-Reported Screen Time in Czech Families with Preschoolers

This study focuses on determining the relationship between parents’ step count (SC) and screen time (ST) and children’s SC and ST on weekdays and at weekends. The participants (278 parents aged 30–45 and their 194 children aged 4–7) were recruited from 10 randomly selected Czech kindergartens. The participants recorded SC and ST duration over a week-long monitoring (≥8 h/day) during September–October 2014 and April–May 2015. The associations between parents’ SC and ST and children’s SC and ST were estimated using general linear regression for weekdays and weekends. Each 2500 SC increase in mothers’/fathers’ daily SC at weekdays (weekends) was associated with an extra 1143/903 (928/753) daily SC in children. Each 60 min of ST increase in mothers’/fathers’ ST at weekdays (weekends) was associated with an extra 7.6/7.6 (16.8/13.0) min of child daily ST. An increase of 2500 mothers’ daily SC was associated with reduction of 2.5 (7.5) min of ST in children at weekdays (weekends). This study reveals a significant relationship between parent-child SC/day, parent-child ST/day, and mothers’ ST and children’s SC at weekends. Weekend days seem to provide a suitable space for the promotion of joint physical activity in parents and their pre-schoolers.

Emergency weight estimation lookup tables for New Zealand children aged 5-10 years

OBJECTIVE

To derive novel emergency weight estimation tables for New Zealand children aged 5-10 years using ethnicity and sex to increase accuracy and precision.

METHODS

Using an existing dataset (collected in five New Zealand primary schools during July 2013; n = 376), body mass index and current emergency weight estimates were calculated. Stepwise regression with Akanke Information produced two best-fit models for predicting weight, one based on age and the other on height. Potential explanatory variables included ethnicity, sex and body habitus.

RESULTS

The length-based model included height, ethnicity and body habitus. Accuracy (weight estimates within 10% of actual weight) for the length-based lookup table (74.8%) was similar to that for the Broselow-Luten tape (73.4%). The age-based model included age, sex, ethnicity and body habitus. Accuracy (51.3%) for the age-based lookup table was better than for existing formulae including Shann (45.7%), Advanced Paediatric Life Support (39.1%) and Theron (28.7%).

CONCLUSION

The most accurate method for weight estimation in Auckland children aged 5-10 years is either the novel length-based lookup table or the existing Broselow-Luten tape. When length-based methods are not possible, the age-based lookup tables incorporating age, sex, ethnicity and body habitus are more accurate than existing methods of weight estimation.

Relationship between Czech Parent and Child Pedometer-assessed Weekday and Weekend Physical Activity and Screen Time

AIM

Uncovering the influences of parents' behaviour on their children's physical activity provides an insight into the lifestyle of families and development of effective family-based interventions. The aim of this study was to determine the relationship between parents' behaviour (step count (SC) and screen time (ST)) and children's SC on weekdays and at weekends.

METHODS

The participants (388 parents aged 35-45 and their 485 children aged 9-12) were randomly recruited from 21 Czech government funded primary schools. The participants recorded SC and ST duration for seven consecutive days (≥ 10 h/day) during April-May and September-October 2013. The associations between parents' behaviour (SC and ST) and children's SC were estimated using general linear regression separately for weekdays and weekends. Each 1,000 SC increase in mothers' (fathers') SC/weekday was associated with an extra 261 SC/day in their daughters and 413 (244) SC/day in their sons.

RESULTS

Each 1,000 SC increase in mothers' (fathers') SC/weekend day was associated with an extra 523 (386) SC/day in their daughters and 508 (435) SC/day in their sons. A reduction in mothers' ST by 30 minutes per weekend day was associated with an extra 494 SC/day in their daughters and 467 SC/day in their sons.

CONCLUSIONS

This study reveals a quantifiable relationship between parent-child SC/day and mothers' ST and children's SC at weekends. Weekend days are more suitable for the implementation of family-based interventions.

Sleep and body mass index in adolescence: results from a large population-based study of Norwegian adolescents aged 16 to 19 years

Background

The aim of this study was to examine the association between body mass index (BMI) and sleep duration, insomnia and symptoms of obstructive sleep apnea (OSA) in adolescents.

Methods

Data were taken from a large population based study of 9,875 Norwegian adolescents aged 16–19. BMI was calculated from the self-reported body weight and categorized according to recommended age and gender specific cut offs for underweight, overweight and obesity. Detailed sleep parameters (sleep duration, insomnia, and OSA symptoms) were reported separately for weekdays and weekends. Data were analyzed using Pearson’s chi-squared test and ANOVAs for simple categorical and continuous comparisons, and multinomial logistic regressions for analyses adjusting for known confounders.

Results

There was evidence for a curvilinear relationship between BMI and both sleep duration and insomnia for girls, whereas the relationship was linear for boys. Compared to the average weekday sleep duration among adolescents in the normal weight range (6 hrs 29 min), both underweight (5 hrs 48 min), overweight (6 hrs 13 min) and obese (5 hrs 57 min) adolescents had shorter sleep duration. OSA symptoms were linearly associated with BMI. Controlling for demographical factors as well as physical activity did not attenuate the associations. Additional adjustment for depression reduced the association between insomnia and obesity to a non-significant level. The evidence for a link between both underweight and overweight/obesity, and short sleep duration and OSA symptoms remained in the fully adjusted analyses. The associations were generally stronger for girls.

Conclusions

This is one of the first population-based studies to investigate the relationship between sleep and BMI in adolescents while simultaneously controlling for important confounding factors. These findings require further research to investigate the temporal association between weights and sleep problems.

Parent-child associations in pedometer-determined physical activity and sedentary behaviour on weekdays and weekends in random samples of families in the Czech Republic

This study investigates whether more physically active parents bring up more physically active children and whether parents’ level of physical activity helps children achieve step count recommendations on weekdays and weekends. The participants (388 parents aged 35–45 and their 485 children aged 9–12) were randomly recruited from 21 Czech government-funded primary schools. The participants recorded pedometer step counts for seven days (≥10 h a day) during April–May and September–October of 2013. Logistic regression (Enter method) was used to examine the achievement of the international recommendations of 11,000 steps/day for girls and 13,000 steps/day for boys. The children of fathers and mothers who met the weekend recommendation of 10,000 steps were 5.48 (95% confidence interval: 1.65; 18.19; p < 0.01) and 3.60 times, respectively (95% confidence interval: 1.21; 10.74; p < 0.05) more likely to achieve the international weekend recommendation than the children of less active parents. The children of mothers who reached the weekday pedometer-based step count recommendation were 4.94 times (95% confidence interval: 1.45; 16.82; p < 0.05) more likely to fulfil the step count recommendation on weekdays than the children of less active mothers.