Determinants of weight gain in children from 7 to 10 years

Relationships of the gut microbiome with cognitive development among healthy school-age children

Background

The gut microbiome might play a role in neurodevelopment, however, evidence remains elusive. We aimed to examine the relationship between the intestinal microbiome and cognitive development of school-age children.

Methods

This cross-sectional study included healthy Israeli Arab children from different socioeconomic status (SES). The microbiome was characterized in fecal samples by implementing 16S rRNA gene sequencing. Cognitive function was measured using Stanford-Binet test, yielding full-scale Intelligence Quotient (FSIQ) score. Sociodemographics and anthropometric and hemoglobin measurements were obtained. Multivariate models were implemented to assess adjusted associations between the gut microbiome and FSIQ score, while controlling for age, sex, SES, physical growth, and hemoglobin levels.

Results

Overall, 165 children (41.2% females) aged 6-9 years were enrolled. SES score was strongly related to both FSIQ score and the gut microbiome. Measures of α-diversity were significantly associated with FSIQ score, demonstrating a more diverse, even, and rich microbiome with increased FSIQ score. Significant differences in fecal bacterial composition were found; FSIQ score explained the highest variance in bacterial β-diversity, followed by SES score. Several taxonomic differences were significantly associated with FSIQ score, including Prevotella, Dialister, Sutterella, Ruminococcus callidus, and Bacteroides uniformis.

Conclusions

We demonstrated significant independent associations between the gut microbiome and cognitive development in school-age children.

Family socioeconomic status and childhood adiposity in Europe - A scoping review

Childhood obesity is a considerable public health problem worldwide. In Europe, lower parental socioeconomic status (SES) relates to higher childhood adiposity. This scoping review strives to discover, which SES indicators are the most commonly used and meaningful determinants of childhood adiposity (greater level of continuous adiposity indicator, e.g. body mass index z-score, or overweight or obesity categorized by established definitions). The review focused on studies about European general populations from the 21st century (January 2000-April 2021) considering children and adolescents aged 0-17 years. PubMed and reference lists of articles were searched in February-April 2021. Total of 53 studies with 121 association analyses between different SES indicators and adiposity indicators, were identified and reviewed. Different SES indicators were grouped to 25 indicators and further to six indicator groups. The most used indicator was mother's education (n of association analyses = 24) and the most used indicator group was parental education (n of association analyses = 51). Of all association analyses, 55% were inverse, 36% were non-significant, and 8% were positive. Composite SES (80%), parental education (69%) and parental occupation (64%) indicators showed most frequently inverse associations with obesity measures (i.e. lower parental SES associating with higher adiposity), while parental income (50% inverse; 50% non-significant) and property and affluence (42% inverse; 50% nonsignificant) indicators showed approximately even number of inverse and non-significant associations. Instead, majority of parental employment (60%) indicators, showed non-significant associations and 33% showed positive associations (i.e. higher parental SES associating with higher adiposity). Despite some variation in percentages, majority of the associations were inverse in each age group and with different outcome categorizations. In girls and in boys, non-significant associations predominated. It seems that children with parents of higher SES have lower likelihood of adiposity in Europe. Parents' employment appears to differ from other SES indicators, so that having an employed parent(s) does not associate with lower likelihood of adiposity. Positive associations seem to occur more frequently in poorer countries. Criteria for uniform childhood SES and adiposity measures should be established and used in studies in order to be able to produce comparable results across countries.

Sedentary Behavior and Obesity in Youth According to Meeting Physical Activity Guidelines: National Health and Nutrition Examination Survey 2003-2006

Background: The purpose of this study was to examine the association between sedentary time and obesity in youth according to meeting physical activity guidelines. Methods: A total of 1991 youth (10-17 years) from the 2003 to 2006 National Health and Nutrition Examination Survey were included in the analysis. Physical activity was categorized into two levels: (1) daily engagement in ≥60 minutes of moderate and vigorous physical activity (MVPA) and (2) <60 minutes per day of MVPA. Sedentary time was categorized into four levels using quartiles. BMI was categorized into two levels using sex-specific BMI for age percentiles from the CDC: (1) obese group: BMI ≥90 percentile and (2) nonobese group: BMI <90 percentile. Results: After adjusting for covariates, among those meeting physical activity guidelines, there was a statistically significant relationship between sedentary time and obesity for Q1 (sedentary time <383.5 min/day) vs. Q4 (sedentary time >523.5 min/day) [odds ratio (OR) = 0.14, 95% confidence interval (CI): 0.02-0.87] and Q2 (sedentary time = 383.5-451.83 min/day) vs. Q4 (sedentary time >523.5 min/day) (OR = 0.16, 95% CI: 0.03-0.99). Among youth not meeting physical activity guidelines, however, sedentary time was not associated with obesity [OR = 0.72 (Q1 vs. Q4), OR = 0.88 (Q2 vs. Q4), OR = 1.08 (Q3 vs. Q4)]. Conclusions: These results indicate that sedentary time is associated with obesity among those meeting physical activity guidelines. However, the relationship between sedentary time and obesity in a low physical activity group is not obvious. Therefore, to confirm the role of low-level physical activity on the relationship between sedentary time and health outcomes, further investigation is required.

The association between area-based deprivation and change in body-mass index over time in primary school children: a population-based cohort study in Hampshire, UK

BACKGROUND/OBJECTIVES

Childhood obesity is a serious public health challenge. Cross-sectional evidence indicates that childhood obesity is strongly linked to area deprivation level, yet longitudinal research is scarce. We assessed the association of home-based and school-based deprivation indices with change in childhood body-mass index (BMI) z-score and BMI status over 6 years in Hampshire, England.

SUBJECTS/METHODS

This longitudinal study linked the National Child Measurement Programme data for children aged 4-5 years (2007-08 to 2009-10) to 10-11 years. The dataset was stratified into two groups: 18,733 children for whom home deprivation quintiles, according to the Index of Multiple Deprivation (IMD), remained constant, and 6153 children who moved home deprivation quintiles between the two time points. The associations between IMD quintiles and change in BMI z-score and status were analysed.

RESULTS

63.7% of children remained a healthy weight, 3.1% remained overweight, 5.3% remained with obesity, 8.3% became overweight, and 10.3% developed obesity. Children living in the most deprived quintile increased their BMI z-score by 0.13 units more than those in the least deprived quintile (95% CI: 0.08-0.19). Home-based deprivation displayed associations with change in BMI status. (Relative risk for the most deprived quintile: become overweight 1.47, 1.21-1.78, remain obese 1.82, 1.34-2.40, become obese 2.07, 1.73-2.48.) School-based deprivation was not associated with change in BMI z-score or BMI status. Moving home to a more deprived quintile was associated with developing obesity (1.22, 1.04-1.43).

CONCLUSIONS

More children living in deprived areas developed obesity over time. Home-based deprivation level is more strongly associated with adverse change in childhood weight than school-based deprivation. Scholarly settings can provide opportunities for interventions, however obesity prevention interventions should tackle the obesogenic environment combining family and area-based measures.

Maternal Characteristics and Incidence of Overweight/Obesity in Children: A 13-Year Follow-up Study in an Eastern Mediterranean Population

Objectives To investigate clustering of parental sociobehavioral factors and their relationship with the incidence of overweight and obesity in Iranian children. Methods Demographics, body weight, and certain medical characteristics of the parents of 2999 children were used to categorize parents by cluster; children's weights were assessed for each cluster. Specifically, survival analysis and Cox regression models were used to test the effect of parental clustering on the incidence of childhood overweight and obesity. Results Maternal metabolic syndrome, education level, age, body weight status, and paternal age had important roles in distinguishing clusters with low, moderate, and high risk. Crude incidence rates (per 10,000 person-years) of overweight and obesity were 416.8 (95% confidence interval (CI) 388.2-447.5) and 114.7 (95% CI 101.2-129.9), respectively. Children of parents with certain constellations of demographic and medical characteristics were 37.0 and 41.0% more likely to become overweight and obese, respectively. Conclusions for Practice The current study demonstrated the vital role of maternal characteristics in distinguishing familial clusters, which could be used to predict the incidence of overweight and obesity in children.

Changes in objectively measured BMI in children aged 4-11 years: data from the National Child Measurement Programme

BACKGROUND

This study looked at the degree of weight gain between the first (Reception) and last year (Year 6) of primary school and how weight status in Reception predicts becoming overweight/obese by Year 6.

METHODS

A longitudinal sample of 1863 children was created using two time points (2006/7, 2012/13) from the National Child Measurement Programme (NCMP) in South Gloucestershire. T-test and logistic regression were used to test the difference between the BMI z-scores and BMI percentiles, and predict the probability of being overweight (BMI ≥ 85th) or obese (≥95th) at Year 6 based on BMI percentile in Reception.

RESULTS

Of those children who were obese at Reception age, 68% were obese at Year 6. Compared with children with a BMI in the 2nd to 49th percentile range, children between the 75th and 84th percentiles of BMI at Reception age were 10 times more likely (odds ratio (OR) = 10.18, P < 0.01), and those with a BMI between the 85th and 94th percentiles were 13 times more likely (OR = 13.38, P < 0.01), to become obese by Year 6. Boys were more likely than girls to revert to a healthy weight.

CONCLUSIONS

This is the first study to link data from the NCMP. It provides estimates of prevalence and offers new evidence on obesity emergence and gender differences.

The stability of weight status through the early to middle childhood years in Australia: a longitudinal study

OBJECTIVES

To investigate the sociodemographic and behavioural factors associated with incidence, persistence or remission of obesity in a longitudinal sample of Australian children aged 4-10 years.

SETTING

Nationally representative Longitudinal Study of Australian Children (LSAC).

PARTICIPANTS

The sample for this analysis included all children in the Kinder cohort (aged 4-5 years at wave 1) who participated in all four waves of LSAC (wave 1, 2004, aged 4-5 years; wave 2, 2006, aged 6-7 years; wave 3, 2008, aged 8-9 years and wave 4, 2010, aged 10-11 years). Of the 4983 children who participated in the baseline (wave 1) survey, 4169 (83.7%) children completed all four waves of data collection.

PRIMARY AND SECONDARY OUTCOME MEASURES

Movement of children between weight status categories over time and individual-level predictors of weight status change (sociodemographic characteristics, selected dietary and activity behaviours).

RESULTS

The study found tracking of weight status across this period of childhood. There was an inverse association observed between socioeconomic position and persistence of overweight/obesity. Sugar-sweetened beverages and fruit and vegetable intake and screen time appeared to be important predictors of stronger tracking.

CONCLUSIONS

Overweight and obesity established early in childhood tracks strongly to the middle childhood years in Australia, particularly among children of lower socioeconomic position and children participating in some unhealthy behaviour patterns.

Unhealthy weight among children and adults in India: urbanicity and the crossover in underweight and overweight

PURPOSE

Urbanization may promote the rise of dual burdens of underweight and overweight in low- and middle-income countries. We assessed underweight and overweight by urban residence across the lifespan in India.

METHODS

Using nationally representative, directly measured height and weight data (2004-2006; n = 236,039), we estimated and compared the prevalence of underweight and overweight (including obesity) at ages 0 to 54 years by urban and rural residence; absolute burdens of underweight, overweight, and combined unhealthy weight were estimated using 2011 Census data.

RESULTS

Thirty-eight percent of the urban population and 36% of the rural population of India experienced unhealthy weight, amounting to 378 million underweight or overweight individuals. In urban areas, the unhealthy weight burden was largely underweight in childhood and overweight in adulthood. In rural areas, the unhealthy weight burden was largely underweight at all ages. Urban residents compared with rural residents were more likely to be overweight and less likely to be underweight at nearly all ages.

CONCLUSIONS

Combined unhealthy weight was comparable in urban and rural India. Although underweight continues to be the predominant nutritional problem, there is early evidence of an epidemiologic crossover from underweight to overweight. As India experiences urbanization and population aging, low overweight and obesity may be short lived.

IQ and obesity in adolescence: a population-based, cross-sectional study

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Low IQ is associated with high BMI in childhood. There are inconsistent findings on the association between low SES and high BMI. Youth with low IQ have been reported to have poorer health behaviors, such as poor nutrition and less physical activity.

WHAT THIS STUDY ADDS

Low IQ is significantly associated with obesity for both male and female adolescents, though more strongly for female adolescents. Physical activity has a mediating effect on the association between low IQ and obesity among both male and female adolescents, though more strongly for male adolescents. The association between low IQ and obesity is strongest among adolescents from high SES backgrounds.

BACKGROUND

Previous studies have shown an association between low intelligence quotient (IQ), high body mass index and low socioeconomic status (SES).

OBJECTIVES

This study examined the cross-sectional association between IQ and obesity, exploring the roles of gender, SES and physical activity in this association.

METHODS

Subjects were 235,663 male and 169,259 female adolescents assessed by the Israeli military draft board.

RESULTS

Low IQ was significantly associated with increased odds of obesity among male (odds ratio [OR] = 1.44, 95% confidence interval [CI] = 1.36-1.52) and female adolescents (OR = 1.61, 95% CI = 1.51-1.73); this association was significantly stronger among female adolescents. Sobel tests indicated that physical activity had a significant mediating effect on this association for male and female adolescents, although more strongly for male adolescents. Dividing the sample according to SES, the association between low IQ and obesity was strongest in the high SES group (male adolescents: OR = 1.26, 95% CI = 1.10-1.43, female adolescents: OR = 1.61, 95% CI = 1.38-1.89), even when controlling for physical activity.

CONCLUSIONS

The findings suggest that low IQ is associated with increased odds of obesity, particularly in female adolescents and in adolescents with high SES. Physical activity has a mediating effect on this association, although more strongly for male than for female adolescents. Public health measures on decreasing obesity might focus on these groups.

Tracking of weight status and body fatness in Italian children

The prevalence of weight disorders among school-aged children is an increasing phenomenon and it is of great importance to identify the characteristics of individuals at risk of gaining or retaining weight. This study aimed to examine the prevalence of weight disorders and their tracking over a 3-year period in a sample of Italian children. Body mass, body height and selected skinfold thicknesses were assessed in 355 children at the age of 7 and 10 years. Tracking of body mass index (BMI), inverted BMI (iBMI) and skinfold-based body fat were analyzed and the relationships between changes in BMI and body fat were examined. Children presenting with overweight or obesity at 7 years old showed a trend toward lower weight categories at 10 years old. Conversely, a trend to become overweight was observed among normal weight boys, and a trend to become underweight was observed among normal weight girls. BMI, iBMI and body fat showed good levels of tracking, with high correlations between measurements performed at 7 and 10 years of age. Furthermore, BMI and iBMI changes were correlated to body fatness changes. The present study shows the importance of carefully following children's development over time because weight disorders may appear even in previously normal weight children.

Low maternal education is associated with increased growth velocity in the first year of life and in early childhood: the ABCD study

The objective of this study is first to examine the relation of maternal education and growth velocity during the first year of life and early childhood (1-5 years). The second objective is to determine the potential explanatory role of standardized birth weight, maternal smoking during pregnancy, maternal prepregnancy body mass index (BMI), and infant feeding practice in this relation. We used longitudinal growth data of 1,684 participants with Dutch ethnicity participating in a population-based cohort study (Amsterdam Born Children and their Development study). Growth velocity of weight and of weight-for-length were calculated by subtracting the weight and weight-for-length standard deviation scores (SDS), respectively of two time periods. In the first year of life, children with low-educated mothers had an increase in SDS of 0.26 (95 % confidence interval (CI) 0.08-0.45) for weight compared to children with high-educated mothers. In early childhood, children with low-educated mothers had a 0.27 SDS (95 % CI 0.11-0.42) increase for weight-for-length, compared to children with high-educated mothers. Using path analysis, these inequalities could partly be explained by maternal smoking, duration of breastfeeding, maternal age, and maternal BMI.

CONCLUSION

Children with low-educated mothers had an increased weight gain during the first year of life and an increased weight-for-length gain in early childhood compared to children with high-educated mothers. Although underlying mechanisms were not completely clarified, an optimal duration of breastfeeding, cessation of maternal smoking, and reduction of maternal BMI seem to reduce these educational inequalities in early growth and possible adverse consequences of accelerated growth.

The non-advertising effects of screen-based sedentary activities on acute eating behaviours in children, adolescents, and young adults. A systematic review

Sedentary screen time may be an important determinant of childhood obesity. A number of potential mechanisms to explain the link between screen time and increased bodyweight have been proposed; however, the relationship appears to be best explained by the effects on dietary intake, which is attributed to either food advertising or effects independent of food advertising. Technological advances have allowed for greater accessibility and exposure to advertisement-free screen-based media. This review was conducted to systematically synthesise the evidence from laboratory based studies which have investigated the non-advertising effects of screen time (TV viewing, sedentary video games, and computer use) on dietary intake in children, adolescents, and young adults. MEDLINE, PubMed, PsychInfo, CINAHL, and Embase were searched from inception through 5 July 2013. Ten trials met the inclusion criteria and were included in the review. Risk of study bias was judged to range from low to high. Screen time in the absence of food advertising was consistently found to be associated with increased dietary intake compared with non-screen behaviours. Suggested explanations for this relationship included: distraction, interruption of physiologic food regulation, screen time as a conditioned cue to eat, disruption of memory formation, and the effects of the stress-induced reward system. Due to the limited number of high-quality studies available for this review, our findings are preliminary. More work is required to better establish the link between dietary intake and advertisement-free screen time and assess whether differences exist between the different screen-based activities.

BMI, waist circumference, and selected cardiovascular disease risk factors among preschool-age children

In adults, overweight is often associated with other cardiovascular disease (CVD) risk factors. We determined whether these associations were also present in young children. This study examined the relationships between elevated BMI (≥85th and ≥95th percentiles for age and sex) and the highest quintile of waist circumference (WC) with CVD risk factors, including fasting triglyceride (TGL), high- and low-density lipoprotein (HDL and LDL), total cholesterol (TC), non-HDL cholesterol, and C-reactive protein (CRP) in 3,644 3- to 6-year-old children included in the 1999-2008 National Health and Nutrition Examination Surveys (NHANES). Results showed that 20% (highest quintile) of the sample had a TC >170 mg/dl, LDL >109 mg/dl, TGL >103 mg/dl, non-HDL >128 mg/dl, CRP >0.13 mg/dl, WC >57.2 cm, and HDL <42 mg/dl. Increased BMI and WC were associated with increased CRP levels in non-Hispanic black boys and girls, Hispanic boys, and non-Hispanic white girls, whereas elevated TGL and non-HDL cholesterol and low HDL cholesterol were generally associated with elevated BMI and WC in Hispanic children. TC and LDL cholesterol were not significantly associated with elevated weight in 3- to 6-year-olds. BMI and WC were similar in predicting the same risk factors. In summary, this analysis shows that in preschool-age children, greater BMI and WC are associated with biomarkers that are related to CVD risk, but these associations vary by ethnicity. Child health providers should consider using both BMI and WC to identify young children who may be at risk for elevated CVD biomarkers.

Medium-term evaluation of an educational intervention on dietary and physical exercise habits in schoolchildren: the Avall 2 study

OBJECTIVE

To assess whether the benefits seen in nutrition, physical activity. and body mass index were maintained at 2 years of completion of the educational intervention.

MATERIAL AND METHODS

An experimental, longitudinal, 4-year, two-arm, parallel study with cluster randomization to assess an intervention program aimed at children in their first year of primary schooling attending schools in the city of Granollers. Intervention consisted of promoting healthy dietary habits and increasing physical activity through the educational pedagogy Investigation, Vision, Action and Change (IVAC), applied over 2 school years (2006-2008). Weight and height of each child wee measured in situ, and families self-completed a physical activity survey and the Krece Plus quick test in 2006, 2008, and 2010.

RESULTS

A greater increase in body mass index was seen in 2010 in children from the control group (2.84 ± 0.22 vs 1.96 ± 0.163 kg/m(2), <.001). Prevalence of overweight and obesity increased by 8% and 0.5% respectively in schoolchildren in the control group, while the intervention group showed a 5.3% increase in prevalence of overweight and a 3.6%decrease in prevalence of obesity. Prevalence of excess weight therefore increased by 8.5% in the control group and by 1.8% in the intervention group. Reduction in body mass indexincrease was maintained 2 years after completion of educational intervention regardless of sex, origin, maternal obesity, and educational level of parents.

CONCLUSIONS

These results confirm that school-based interventions may help contain the current increase in childhood obesity.

Individual and social determinants of multiple chronic disease behavioral risk factors among youth

BACKGROUND

Behavioral risk factors are known to co-occur among youth, and to increase risks of chronic diseases morbidity and mortality later in life. However, little is known about determinants of multiple chronic disease behavioral risk factors, particularly among youth. Previous studies have been cross-sectional and carried out without a sound theoretical framework.

METHODS

Using longitudinal data (n = 1135) from Cycle 4 (2000-2001), Cycle 5 (2002-2003) and Cycle 6 (2004-2005) of the National Longitudinal Survey of Children and Youth, a nationally representative sample of Canadian children who are followed biennially, the present study examines the influence of a set of conceptually-related individual/social distal variables (variables situated at an intermediate distance from behaviors), and individual/social ultimate variables (variables situated at an utmost distance from behaviors) on the rate of occurrence of multiple behavioral risk factors (physical inactivity, sedentary behavior, tobacco smoking, alcohol drinking, and high body mass index) in a sample of children aged 10-11 years at baseline. Multiple behavioral risk factors were assessed using a multiple risk factor score. All statistical analyses were performed using SAS, version 9.1, and SUDAAN, version 9.01.

RESULTS

Multivariate longitudinal Poisson models showed that social distal variables including parental/peer smoking and peer drinking (Log-likelihood ratio (LLR) = 187.86, degrees of freedom (DF) = 8, p < .001), as well as individual distal variables including low self-esteem (LLR = 76.94, DF = 4, p < .001) increased the rate of occurrence of multiple behavioral risk factors. Individual ultimate variables including age, sex, and anxiety (LLR = 9.34, DF = 3, p < .05), as well as social ultimate variables including family socioeconomic status, and family structure (LLR = 10.93, DF = 5, p = .05) contributed minimally to the rate of co-occurrence of behavioral risk factors.

CONCLUSIONS

The results suggest targeting individual/social distal variables in prevention programs of multiple chronic disease behavioral risk factors among youth.

Socioeconomic inequalities in childhood obesity in the United Kingdom: a systematic review of the literature

Childhood obesity is a major public health challenge worldwide. There is a growing literature documenting socioeconomic inequalities in childhood obesity risk. Here we draw inference from the literature about inequalities in childhood obesity risk in the UK. We summarize and appraise the extant peer-reviewed literature about socioeconomic inequalities in childhood obesity in the UK. Common area-level indices of socioeconomic position, including the Carstairs Deprivation Index, the Index of Multiple Deprivation and the Townsend Deprivation Index, as well as common household and individual-level metrics of childhood socioeconomic position, including head-of-household social class and maternal education, were generally inversely associated with childhood obesity in the UK. We summarize key methodological limitations to the extant literature and suggest avenues for future research.

Children's weight status and maternal and paternal feeding practices

Child obesity has become a major concern of health researchers. This study explores the association between parental feeding practices and children's weight status. The study also examines whether maternal and paternal feeding practices lead to significantly different children's weight outcomes. By analyzing samples of 312 children (aged 9-11 and 13-15) and their parents, randomly selected from the Houston Metropolitan Statistical Area, the results show that parental feeding practices are linked to children's weight status. The finding that maternal and paternal feeding practices do not have significantly different effects on children's weight highlights an equivalent role of maternal and paternal feeding practices in shaping children's weight status.

Effects of adiposity on physical activity in childhood: Iowa Bone Development Study

PURPOSE

The aim of this study was to examine whether adiposity level is associated with subsequent physical activity (PA) level in childhood.

METHODS

Study participants were 326 children participating in the Iowa Bone Development Study. PA and fat mass were measured using accelerometers and dual-energy x-ray absorptiometry (DXA) at approximately 5, 8, and 11 yr. Data for relevant variables such as parents' education and PA levels and family income were also collected. Gender-specific generalized linear models were fit to examine the association between percentage body fat (%BF) at age 8 and intensity-weighted moderate- to vigorous-intensity PA (IW-MVPA) at age 11.

RESULTS

After adjusting for IW-MVPA at age 8, the interval between the age 8 and 11 examinations, residualized change scores of %BF and IW-MVPA from age 5 to 8, and mother's education level, %BF at age 8 was negatively associated with IW-MVPA at age 11 among boys (P < 0.05). After adjusting for IW-MVPA at age 8, physical maturity, and family income, %BF at age 8 was negatively associated with IW-MVPA at age 11 among girls (P < 0.05). Categorical data analysis also showed that the odds ratio (OR) of being in the lowest quartile relative to the highest quartile of IW-MVPA at age 11 for boys and girls with high %BF at age 8 were approximately four times higher than the OR for those with low %BF at age 8 (OR = 4.38, 95% CI = 1.05-18.24 for boys; OR = 4.48, 95% CI = 1.35-14.85 for girls).

CONCLUSIONS

This study suggests that adiposity level may be a determinant of PA behavior. Specific intervention strategies for overweight children may be needed to promote PA.

Associations between severity of obesity in childhood and adolescence, obesity onset and parental BMI: a longitudinal cohort study

OBJECTIVE

To explore the relationship between severity of obesity at age 7 and age 15, age at onset of obesity, and parental body mass index (BMI) in obese children and adolescents.

DESIGN

Longitudinal cohort study.

SUBJECTS

Obese children (n = 231) and their parents (n = 462) from the Swedish National Childhood Obesity Centre.

METHODS

Multivariate regression analyses were applied with severity of obesity (BMI standard deviation score (BMI SDS)) and onset of obesity as dependent variables. The effect of parental BMI was evaluated and in the final models adjusted for gender, parental education, age at onset of obesity, severity of obesity at age 7 and obesity treatment.

RESULTS

For severity of obesity at age 7, a positive correlation with maternal BMI was indicated (P = 0.05). Severity of obesity at this age also showed a strong negative correlation with the age at onset of obesity. Severity of obesity at age 15 was significantly correlated with both maternal and paternal BMI (P < 0.01). In addition, BMI SDS at age 15 differed by gender (higher for boys) and was positively correlated with severity of obesity at age 7 and negatively correlated with treatment. Also, a negative correlation was indicated at this age for parental education. No correlation with age at onset was found at age 15. For age at onset of obesity there was no relevant correlation with parental BMI. Children within the highest tertile of the BMI SDS range were more likely to have two obese parents.

CONCLUSION

The impact of parental BMI on the severity of obesity in children is strengthened as the child grows into adolescence, whereas the age at onset is probably of less importance than previously thought. The influence of parental relative weight primarily affects the severity of childhood obesity and not the timing.

Sobrepeso e obesidade em escolares brasileiros de sete a nove anos: dados do projeto Esporte Brasil

OBJETIVO: Descrever a prevalência de sobrepeso e obesidade em escolares brasileiros de sete a nove anos e verificar a associação com as variáveis: sexo, idade e região geográfica. MÉTODOS: Estudo epidemiológico transversal conduzido em 2.913 escolares (1.478 do sexo masculino e 1.435 do feminino) com idade entre sete e nove anos. Como critério de diagnóstico de sobrepeso e obesidade foram utilizados os pontos de corte do índice de massa corpórea, propostos pela International Obesity Task Force. A comparação entre as proporções foi realizada mediante o teste qui-quadrado. As diferenças entre as proporções foram testadas por meio do teste de comparação entre duas proporções. RESULTADOS: A prevalência de sobrepeso e obesidade foi de 15,4 e 7,8% em meninos e meninas, respectivamente, com proporções similares entre sexo e idades. No sexo masculino, foi verificada associação do sobrepeso e obesidade apenas com região geográfica (p<0,001), com prevalências mais elevadas nas crianças da região Sul. No feminino, sobrepeso mais elevado foi observado nas crianças de sete anos da região Norte, enquanto a prevalência de obesidade foi maior nas crianças da região Sul. CONCLUSÕES: As crianças da região Sul apresentam maiores prevalências de sobrepeso e obesidade que aquelas das demais regiões do país. Os achados do presente estudo apontam uma tendência de aumento na prevalência de sobrepeso e obesidade na infância e corroboram os resultados encontrados em pesquisas mais abrangentes realizadas no Brasil.

Associação entre o índice de massa corporal de pais e de escolares de 7 a 14 anos de Florianópolis, SC, Brasil

OBJETIVOS: verificar a associação entre o Índice de Massa Corporal (IMC) de escolares de 7 a 14 anos e dos respectivos pais. MÉTODOS: estudo transversal com 886 escolares de quatro escolas de Florianópolis, SC. Diagnóstico antropométrico dos escolares e dos pais definido, respectivamente, a partir do IMC para idade de acordo com Centers for Disease Control and Prevention e dos pontos de corte da Organização Mundial da Saúde. A associação entre o IMC dos pais e dos escolares foi estimada por meio da razão de prevalência (RP) com intervalo de confiança (IC) de 95% e teste qui-quadrado com valor de significância de p< 0,05. RESULTADOS: identificou-se prevalência de sobrepeso/obesidade mais elevada em meninos (29,9%) quando comparada a de meninas (17,7%) (p<0,001). Observou-se relação estatisticamente significante entre o IMC de escolares do sexo feminino com o IMC das mães (RP=1,63; IC95%=1,1-3,0; p=0,02) e dos pais (RP=1,78; IC95%= 1,1-3,5; p=0,01). Nos escolares do sexo masculino a associação observada não foi estatisticamente significante. CONCLUSÕES: identificou-se que a prevalência do sobrepeso ou obesidade é 1,63 vezes maior, entre as meninas, quando a mãe também apresenta esse distúrbio e 1,78 vezes maior quando o pai o apresenta, em comparação a mães e pais eutróficos ou de baixo peso.

Determinants of the prevalence and incidence of overweight in children and adolescents

Objective

To systematically analyse determinants of overweight prevalence and incidence in children and adolescents, as a basis of treatment and prevention.

Design

Cross-sectional and longitudinal data of the Kiel Obesity Prevention Study (KOPS).

Setting

Schools in Kiel, Germany.

Subjects

Cross-sectional data from 6249 students aged 5–16 years and 4-year longitudinal data from 1087 children aged 5–11 years. Weight status of students was assessed and familial factors (weight status of parents and siblings, smoking habits), social factors (socio-economic status, nationality, single parenting), birth weight as well as lifestyle variables (physical activity, media time, nutrition) were considered as independent variables in multivariate logistic regression analyses to predict the likelihood of the student being overweight.

Results

The cross-sectional data revealed the prevalence of overweight as 18·3 % in boys and 19·2 % in girls. In both sexes determinants of overweight prevalence were overweight and obese parents, overweight siblings, parental smoking, single parenthood and non-German nationality. High birth weight and low physical activity additionally increased the risk in boys. High media time and low parental education were significant determinants in girls. Effect of media time was mediated by maternal weight status in boys as well as by socio-economic status and age in girls. From the longitudinal data, the 4-year cumulative incidence of overweight was 10·0 % in boys and 8·2 % in girls. Parental obesity, parental smoking and low physical activity were determinants of overweight incidence in boys, whereas paternal obesity increased the risk in girls.

Conclusions

Treatment and prevention should address family and social determinants with a focus on physical activity and media use.

Trends in body mass in Swedish adolescents between 2001 and 2007

AIM

(1) Compare BMI standard deviation scores (BMIsds) in 16-year olds in 2001 and 2007 to assess trends. (2) Describe tracking of BMIsds between ages 10 and 16 years, in a longitudinal 6-year follow-up. (3) Identify possible predictors in 2001 for high BMIsds in 2007 and increase in BMIsds between 2001 and 2007.

METHODS

A six-year follow-up study on 296 subjects, aged 10 years at baseline and a panel study among 16-year olds. BMIsds was used as the main outcome. RESULTS. No difference in BMIsds in 16-year-old adolescents was found between 2001 and 2007. Strong tracking (r = 0.80, 95% CI: 0.75-0.84) was found for BMIsds between ages 10 and 16 years. Low aerobic capacity and high BMIsds at age 10 years predicted overweight at age 16 years. High BMIsds in 2001 predicted a decline in BMIsds (OR: 0.58, 95% CI: 0.43-0.76) and high level of self-reported moderate-to-vigorous physical activity predicted an increased BMIsds (OR: 1.38, 95% CI: 1.13-1.67).

CONCLUSION

There was no difference in prevalence of overweight plus obesity between the 2001 and 2007 samples. Normal weight and good aerobic fitness in 10-year-old children seems to decrease the risk of elevated relative BMI in 16-year olds.

Contribution of early weight gain to childhood overweight and metabolic health: a longitudinal study (EarlyBird 36)

BACKGROUND

Early weight gain (0-5 years) is thought to be an important contributor to childhood obesity and consequently metabolic risk. There is a scarcity of longitudinal studies in contemporary children reporting the impact of early weight gain on metabolic health.

OBJECTIVE

We aimed to assess the impact of early weight gain on metabolic health at 9 years of age.

METHOD

Two hundred thirty-three children (134 boys, 99 girls) with a gestational age of >37 weeks were assessed at birth, 5 years of age, and 9 years of age. Measures included weight SD scores at each time point and excess weight gained (Delta weight SD score) between them. The outcome measure included composite metabolic score (sum of internally derived z scores of insulin resistance, mean blood pressure, triglyceride level, and total cholesterol/high-density lipoprotein cholesterol ratio).

RESULTS

Weight SD score increased by 0.29 SD score in girls and 0.26 SD score in boys from 0 to 5 years of age and by 0.03 SD score in girls and 0.11 SD score in boys from 5 to 9 years of age. Weight SD score correlated poorly to moderately before 5 years of age but strongly after 5 years of age. Birth weight SD score predicted (girls/boys) 2.4%/0% of the variability in composite metabolic score at 9 years of age. Adding Delta weight SD score (0-5 years old) contributed (girls/boys) 11.2%/7.0% to the score, and adding Delta weight SD score (5-9 years old) additionally contributed (girls/boys) 26.4%/16.5%. Importantly, once weight SD score at 9 years of age was known, predictive strength was changed little by adding Delta weight SD score.

CONCLUSIONS

Most excess weight before puberty is gained before 5 years of age. Weight at 5 years of age bears little relation to birth weight but closely predicts weight at 9 years of age. Single measures of current weight are predictive of metabolic health, whereas weight gain within a specific period adds little. A single measure of weight at 5 years of age provides a pointer to future health for the individual. If metabolic status at 9 years of age means future risk, diabetes/cardiovascular prevention strategies might better focus on preschool-aged children, because the die seems to be largely cast by 5 years of age, and a healthy weight early in childhood may be maintained at least into puberty.

Sedentary behaviour and obesity development in children and adolescents

Sedentary lifestyle patterns in children and adolescents, i.e. playing digital games, using computers and especially watching television, have been associated with obesity. However, not all sedentary behaviour has shown the same relevance to, and relationship with, obesity. Therefore, we conducted a review including published studies found in PubMed and other medical journals, dated between January 1990 and April 2007. The ages of the children and adolescents who were the object of the study ranged between 2 and 18 years. For the purpose of this paper, we selected cross-sectional, longitudinal and intervention studies. Sufficient evidence exists to recommend setting a limit to the time spent watching TV, especially for younger children. However, video games and computers do not represent such a high risk compared to watching TV, when they do not replace physical activity too much. In fact, there is no evidence to suggest that sedentary behaviour displaces physical activity levels. Mechanisms that explain the link between sedentariness and obesity are also discussed. Finally, future studies should take into account important mediators such as socioeconomic status and family structure.

Primary prevention of childhood obesity: an interdisciplinary analysis

The primary prevention of childhood obesity requires combined efforts by stakeholders at various societal levels, based on the knowledge from multiple disciplines. The goal of the present study was therefore to analyze current preventive approaches and delineate implications for future prevention research and practice by integrating knowledge from genetics, law, economics, psychology, and social ethics. Inconclusive evidence on the etiology of obesity, a complex, multifactorial condition, likely complicates prevention, leading to a lack of specificity regarding target groups, focus, and techniques. It is recommended to increase the specificity of prevention by explicitly considering risk factor evidence, including evidence on genetic factors. Because the institutional and legal framework of primary obesity prevention in children is insufficient in many countries, considering the risk factors for childhood obesity is also crucial for establishing a basis for legal regulations. Companies from sectors concerned with food intake and physical activity may be involved in preventive action, e.g., for initiating self-defeating sanctions. Long-term behavior change may be enhanced through the systematic application of behavior modification techniques within primary prevention programs. Overall, an interdisciplinary perspective furthers understanding of the complexity of this condition and can inform public health strategies on the primary prevention of childhood obesity.

A high-precision protocol for identification of preschool children at risk for persisting obesity

BACKGROUND

Recent studies suggest that adolescent adiposity is established already in preadolescence. Earlier studies have confirmed a strong tracking of obesity from adolescence to adulthood. Our aim was to examine the diagnostic accuracy of a population-derived protocol for identification of preschool children at risk for obesity in preadolescence.

METHODOLOGY/PRINCIPAL FINDINGS

We analysed data obtained for child health surveillance up to age 5 from 5778 children born in a Swedish county in 1991. The basic data set included age, sex, and weight and height measurements from the regular checkups between ages 1.5 and 5. Data not routinely collected in the child health centre setting were disregarded. The children were at age 10 randomly assigned to protocol derivation and validation cohorts and assessed for obesity according to IOTF criteria. The accuracy of predicting obesity in the validation cohort was measured using decision precision, specificity, and sensitivity. The decision protocol selected 1.4% of preschool children as being at obesity risk. The precision of the protocol at age 10 was 82% for girls and 80% for boys, and the specificity was 100% for both boys and girls. The sensitivity was higher for girls (41%) than for boys (21%). The relative risk for obesity at age 10 estimated by the odds ratio for individuals selected by the protocol compared to non-selected peers was 212.6 (95% confidence interval 56.6 to 798.4) for girls and 120.3 (95% CI 24.5 to 589.9) for boys.

CONCLUSION/SIGNIFICANCE

A simple and inexpensive decision protocol based on BMI values proved to have high precision and specificity for identification of preschool children at risk for obesity persisting into adolescence, while the sensitivity was low especially for boys. Implementation and further evaluations of the protocol in child health centre settings are warranted.