Socioeconomic position and body composition in childhood in high- and middle-income countries: a systematic review and narrative synthesis

Adherence to the Mediterranean diet and changes in body mass index

BACKGROUND

Diet is considered a determinant of weight status, however, more evidence is needed for children. The Mediterranean diet (MedDiet) is one of the healthiest worldwide. This study analyzes the prospective association between adherence to the MedDiet at baseline and changes in standardized body mass index (zBMI) and the incidence of excessive weight.

METHODS

1389 children participated with a follow-up of 15 months. Weight, height, and adherence to the MedDiet were measured (baseline and follow-up).

RESULTS

Multiple logistic regression analysis revealed that a high increase in zBMI was associated with lower odds of eating vegetables once [OR 0.74 (95% CI 0.57-0.98)] or more a day [OR 0.68 (95% CI 0.49-0.95)], nuts 2-3 times/week [OR 0.74 (95% CI 0.56-0.97)] or 2 cups of yogurt or/and cheese daily [OR 0.74 (95% CI 0.55-0.99)]. Not consuming each food item was used as reference. Multiple linear regression analysis showed a negative (β = -0.010, p = 0.040) association between the MedDiet at baseline and changes in zBMI at follow-up, significance disappeared (p = 0.082) after final adjustment for baseline zBMI.

CONCLUSION

Baseline MedDiet was not significantly associated with the incidence of excessive weight at follow-up. The MedDiet was positively associated with changes in zBMI, however the effect size was small.

IMPACT

The present longitudinal study contributes knowledge regarding the adherence to Mediterranean diet as a predictive variable of weight status evolution in children. Higher adherence to the Mediterranean diet at baseline was prospectively and inversely associated with changes in zBMI after 15 months of follow-up. Consuming vegetables, nuts, and yoghurt/cheese according to the recommendations reduces the likelihood of having a high increase in zBMI after 15 months of follow-up.

Socioeconomic Status and Obesity

Obesity is a pervasive public health problem that causes debilitating complications across the life course. One opportunity for preventing the onset of obesity is to focus on its social determinants. Socioeconomic status (SES), which includes factors such as income, educational attainment, occupational prestige, and access to resources, is a key determinant of obesity. In this scoping mini-review, we summarized review articles and meta-analyses of the SES-obesity association. From the 1980s to the present, cross-sectional studies have demonstrated a persistent socioeconomic gradient in obesity in which the association is negative in developed countries and positive in developing countries. Longitudinal studies have revealed the bidirectionality of the SES-obesity association; some studies demonstrate that socioeconomic adversity precedes the onset of obesity, while others provide evidence of reverse causality. While earlier studies relied on anthropometric assessments of weight and height to define obesity, the use of modern technologies like dual-energy x-ray absorptiometry and bioelectrical impedance have demonstrated that the socioeconomic gradient in obesity is robust across multiple indicators of body composition, including direct measures of lean and fat mass. More recently, examination of mediators and moderators of the SES-obesity association have highlighted causal pathways and potential intervention targets, with a focus on health behaviors, environmental conditions, psychological factors, and biological processes. We describe current gaps in knowledge and propose opportunities for future innovation to reduce the burden of obesity and related socioeconomic disparities.

The socioeconomic gradient in overweight and obesity among Colombian adult and pediatric populations: A scoping review

Background: The imminent increase in overweight and obesity prevalence constitutes a pervasive concern for the adult and pediatric Colombian population. Nonetheless, the unequal distribution across distinct social groups limits the implementation of public health policies targeting these escalating rates. Aim: This study aimed to compile existing evidence regarding the prevalence of overweight and obesity in relation to the socioeconomic status (SES) of the Colombian population. Methods: A scoping review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews parameters in MEDLINE (PubMed), EMBASE, and LILACS databases for inclusion of investigations published up to January 2024. Results: Twenty-two cross-sectional studies were included. A higher prevalence of overweight and obesity was documented in adults with lower SES defined by social stratum and monetary income, while in particular for nonpregnant adult women, the prevalence of excess weight was higher in the medium-low socioeconomic stratum. In the pediatric population, higher SES defined by social stratum was directly related to an increased prevalence and risk of overweight and obesity. The ownership of household assets, however, was positively related to the risk of overweight in both adult and pediatric populations. Conclusion: The findings of this investigation disclose a socioeconomic gradient in overweight and obesity in Colombia that resembles the epidemiological distribution in high-income countries for adults, though similar to low-income countries for the pediatric population. Further intersectoral interventions aimed at the most vulnerable groups are imperative to mitigate the inequalities that condition their predisposition to overweight and obesity.

Changes in social inequalities in excess body weight and body dissatisfaction among adolescents in Barcelona, Spain, 2016-2021

OBJECTIVES

Adolescence is a crucial life stage that can lead to excess weight and body dissatisfaction. Social inequalities in these issues may have been exacerbated by the COVID-19 pandemic. We aimed to analyze the presence of socioeconomic inequalities and their changes in these inequalities stratified by sex in 13- to 19-year-olds in a large Mediterranean city (Barcelona, Spain).

STUDY DESIGN

Cross-sectional population-based study.

METHODS

We used data from the 2016 and 2021 editions of the FRESC survey, which is a representative citywide survey that captures various aspects of adolescent health. Excess weight was determined by objective body mass index measurements. Body dissatisfaction was defined as the discrepancy between perceived and desired body shape. Socioeconomic status was divided into five pseudo-quintiles by using the Family Affluence Scale. We calculated the corresponding prevalence estimates and fitted robust Poisson regression models to estimate both simple and complex measures of inequality, including relative and absolute differences between the two survey years.

RESULTS

The overall prevalence of excess weight increased from 25.3% [23.9-26.6] to 29.8% [28.2-31.4] between 2016 and 2021. Similarly, body dissatisfaction increased from 44.2% [42.6-45.8] to 60.4% [58.7-62]. Socioeconomic inequalities in excess weight significantly increased in girls (adjusted ratio of the relative index of inequalities = 1.72 [1.08; 2.74] but not in boys. No significant changes were detected in body dissatisfaction in either girls or boys.

CONCLUSIONS

Our findings highlight the presence of a sex-specific change in socioeconomic inequalities in adolescent well-being regarding excess weight and body dissatisfaction. These results underscore the need for local public policies to improve social equity in adolescent health.

Change in neighborhood socioeconomic status and childhood weight status and body composition from birth to adolescence

BACKGROUND

We aim to assess the associations between the change in neighborhood socioeconomic score (SES) between birth and 6 years and childhood weight status and body composition from 6 to 13 years.

METHODS

Data for 3909 children from the Generation R Study, a prospective population-based cohort in the Netherlands were analyzed. The change in neighborhood SES between birth and 6 years was defined as static-high, static-middle, static-low, upward, and downward mobility. Child body mass index (BMI), overweight and obesity (OWOB), fat mass index (FMI) and lean mass index (LMI) were measured at age 6, 10, and 13 years. The associations were explored using generalized estimating equations. The effect modification by child sex was examined.

RESULTS

In total, 19.5% and 18.1% of children were allocated to the upward mobility and downward mobility neighborhood SES group. The associations between the change in neighborhood SES and child weight status and body composition were moderated by child sex (p < 0.05). Compared to girls in the static-high group, girls in the static-low group had relatively higher BMI-SDS (β, 95% confidence interval (CI): 0.24, 0.09-0.40) and higher risk of OWOB (RR, 95% CI: 1.98, 1.35-2.91), together with higher FMI-SDS (β, 95% CI: 0.27, 0.14-0.41) and LMI-SDS (β, 95% CI: 0.18, 0.03-0.33). The associations in boys were not significant.

CONCLUSIONS

An increased BMI and fat mass, and higher risk of OWOB from 6 to 13 years were evident in girls living in a low-SES neighborhood or moving downward from a high- to a low-SES neighborhood. Support for children and families from low-SES neighborhoods is warranted.

Differences in the temporal trends of childhood overweight and obesity in Spain in the 2011-2019 period by sex, age and socioeconomic level: results of the ALADINO study

INTRODUCTION

Childhood excess weight is a growing public health problem. The aim of this study was to assess temporal trends in the prevalence of overweight, obesity and central obesity in schoolchildren aged 6-9 years in Spain between 2011 and 2019 based on demographic and socioeconomic characteristics.

METHODOLOGY

The analysis included data from the 2011, 2015 and 2019 rounds of the cross-sectional observational and descriptive ALADINO study in schoolchildren of both sexes aged 6-9 years. We conducted a descriptive analysis of the trends in the prevalence of overweight and obesity (defined according to the criteria of the World Health Organization and the International Obesity Task Force) and of central obesity, in addition to associated demographic and socioeconomic variables.

RESULTS

Between 2011 and 2019, the prevalence of overweight (WHO criteria) decreased in boys aged 6, 7 and 8 years (by -5.4%, -5.7% and -5.3%, respectively) and boys whose parents had a higher educational attainment (by -5.3%). In relation to the socioeconomic level, overweight in boys declined at all income levels. However, between 2011 and 2019, both the prevalence of overweight in girls and the prevalence of obesity (applying the WHO and IOTF criteria) and the prevalence of central obesity in both sexes remained stable.

CONCLUSIONS

The prevalence of overweight and the prevalence of obesity in schoolchildren aged 6-9 years in Spain remain high. Between 2011 and 2019, the prevalence of overweight in children aged 6-8 years and in children whose parents had university degrees decreased, whereas obesity in boys, overweight and obesity in girls and central obesity in both sexes remained stable.

Reasons and promotion strategies of physical activity constraints in obese/overweight children and adolescents

To explore the reasons for low levels of physical activity in obese/overweight children and adolescents and to propose appropriate strategies to promote their physical activity (PA). This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by searching and analyzing the literature of studies related to physical activity in obese/overweight children and adolescents published between January 2003 and January 2023 in Web of Science, Scopus, and PubMed databases. A total of 31 relevant studies were included for analysis, of which 16 were quantitative and 15 qualitative. According to these studies, the PA of obese/overweight children and adolescents is mainly constrained by negative factors: Individual, interpersonal, and environmental. Among these factors, low levels of individual motivation and psychological sensitivity and vulnerability, lack of family support, negative social feedback, insufficient protection from government policies, and inadequate support from the built environment are the main reasons that constrain their PA. The promotion of PA in obese/overweight children and adolescents, who are subject to more constraints at all levels, requires a system of security that involves the government, the community, the school, and the family to address the problems they encounter and enhance the sustainability of engagement in PA.

Birth-to-childhood tracking of linear growth and weight gain in the MINA-Brazil Study

OBJECTIVE

To investigate birth-to-childhood tracking of linear growth and weight gain across the distribution of length/height and weight for age z-scores and according to household wealth.

METHODS

Data from 614 children from the MINA-Brazil Study with repeated anthropometric measurements at birth and up to age five years were used. Z-scores were calculated for length/height (HAZ) and weight (WAZ) according to international standards. Birth-to-childhood tracking was separately estimated using quantile regression models for HAZ and WAZ, extracting coefficients and 95% confidence intervals (95%CI) at the 25th, 50th, and 75th quantiles. In a subgroup analysis, we estimated tracking between birth and age two years, and between ages two and five years. To investigate disparities in tracking, interaction terms between household wealth indexes (at birth and age five years) and newborn size z-scores were included in the models.

RESULTS

Tracking coefficients were significant and had similar magnitude across the distribution of anthropometric indices at age five years (HAZ, 50th quantile: 0.23, 95%CI: 0.11 to 0.35; WAZ, 50th quantile: 0.31, 95%CI: 0.19 to 0.43). Greater tracking was observed between ages two and five years, with coefficients above 0.82. Significantly higher tracking of linear growth was observed among children from wealthier households, both at birth, at the lower bounds of HAZ distribution (25th quantile: 0.30, 95%CI: 0.13 to 0.56), and during childhood, in the entire HAZ distribution at five years. For weight gain, stronger tracking was observed at the upper bounds of WAZ distribution at age five years among children from wealthier households at birth (75th quantile: 0.59, 95%CI: 0.35 to 0.83) and during childhood (75th quantile: 0.54, 95%CI: 0.15 to 0.93).

CONCLUSION

There was significant tracking of HAZ and WAZ since birth, with indication of substantial stability of nutritional status between ages two and five years. Differential tracking according to household wealth should be considered for planning early interventions for preventing malnutrition.

Developmental trajectory of appetitive traits and their bidirectional relations with body mass index from infancy to early childhood

Appetitive traits, including food responsiveness, enjoyment of food, satiety responsiveness and slowness in eating, are associated with childhood body mass index. Change in appetitive traits from infancy to childhood and the direction of causality between appetitive traits and body mass index are unclear. The present study examined the developmental trajectory of appetitive traits and their bidirectional relations with body mass index, from infancy to early childhood. Mothers in the Pregnancy Eating Attributes Study and follow-up (n = 162) reported child appetitive traits using the Baby and Child Eating Behaviour Questionnaires at ages 6 months and 3.5 years, respectively. Standardized body mass index (zBMI) was calculated from child anthropometrics. Cross-lagged panel models estimated bidirectional relations between appetitive traits and zBMI. Food responsiveness, satiety responsiveness and slowness in eating increased from infancy to early childhood. In cross-lagged panel models, lower infant satiety responsiveness (B ± SE = -0.45 ± 0.19, p = .02) predicted greater child zBMI. Infant zBMI did not predict child appetitive traits (p-values >.36). From infancy to early childhood, appetitive traits may amplify. Appetitive traits, particularly satiety responsiveness, appear to influence body mass index during this period, suggesting early intervention targeting these traits may reduce childhood obesity.

Overadjustment bias in systematic reviews and meta-analyses of socio-economic inequalities in health: a meta-research scoping review

BACKGROUND

Overadjustment bias occurs when researchers adjust for an explanatory variable on the causal pathway from exposure to outcome, which leads to biased estimates of the causal effect of the exposure. This meta-research review aimed to examine how previous systematic reviews and meta-analyses of socio-economic inequalities in health have managed overadjustment bias.

METHODS

We searched Medline and Embase until 16 April 2021 for systematic reviews and meta-analyses of observational studies on associations between individual-level socio-economic position and health outcomes in any population. A set of criteria were developed to examine methodological approaches to overadjustment bias adopted by included reviews (rated Yes/No/Somewhat/Unclear).

RESULTS

Eighty-four reviews were eligible (47 systematic reviews, 37 meta-analyses). Regarding approaches to overadjustment, whereas 73% of the 84 reviews were rated as Yes for clearly defining exposures and outcomes, all other approaches were rated as Yes for <55% of reviews; for instance, 5% clearly defined confounders and mediators, 2% constructed causal diagrams and 35% reported adjusted variables for included studies. Whereas only 2% included overadjustment in risk of bias assessment, 54% included confounding. Of the 37 meta-analyses, 16% conducted sensitivity analyses related to overadjustment.

CONCLUSIONS

Our findings suggest that overadjustment bias has received insufficient consideration in systematic reviews and meta-analyses of socio-economic inequalities in health. This is a critical issue given that overadjustment bias is likely to result in biased estimates of health inequalities and accurate estimates are needed to inform public health interventions. There is a need to highlight overadjustment bias in review guidelines.

Changes in dietary habits and BMI z-score after a 6-month non-randomized cluster-controlled trial among 6-12 years old overweight and obese Norwegian children

Background

Effective prevention programs to address the high prevalence of childhood overweight and obesity and the concomitant health consequences have been warranted.

Objective

To improve dietary habits and weight status among Norwegian children with overweight/obesity in the primary care setting.

Design

A 6-month non-randomized cluster-controlled intervention among 137 children, aged 6-12 years, with overweight/obesity and their parents. Intervention and control groups were recruited by public health nurses and followed-up by 12 Healthy Life Centers across Norway. The intervention group received individual family counseling and participated in nutrition courses and physical activity groups. A frequency questionnaire assessing sociodemographic characteristics and dietary habits was completed by the parents. Trained public health nurses measured height and weight using standardized methods to calculate body mass index (BMI) and BMI z-scores.

Results

The intervention resulted in an increased odds of consuming evening meals (OR: 3.42), a decreased availability of salty snacks (β = -0.17), a decreased intake of salty snacks (-0.18), an increased consumption of water (β = 0.20), and a decreased estimated total intake of energy (β = -0.17), carbohydrates (β = -0.17), mono- and disaccharides (β = -0.21), sucrose (β = -0.24), and saturated fatty acids (β = -0.17). The intervention directly predicted lower BMI z-score (β = -0.17), and post-treatment levels of energy (β = -0.65), saturated fat (β = 0.43), and total carbohydrates (β = 0.41) were directly linked to BMI z-score after intervention. Age and sex were indirectly associated with BMI after intervention through energy and saturated fat intake.

Conclusions

The intervention had a beneficial impact on nutrient intake and weight status among children with overweight/obesity. These findings provide support for implementing complex intervention programs tailored to local primary care settings.

Trial registration

Clinicaltrials.gov, NCT02290171. Registered 13. November 2014, https://clinicaltrials.gov/ct2/show/NCT02290171.

Infant body composition at 6 and 24 months: what are the driving factors?

BACKGROUND/OBJECTIVE

Available evidence on infant body composition is limited. This study aimed to investigate factors associated with body composition at 6 and 24 months.

SUBJECTS/METHODS

Multicenter study with data from a 0 to 6-mo cohort (Australia, India and South Africa) and a 3 to 24-mo cohort (Brazil, Pakistan, South Africa, and Sri Lanka). For the 0-6-mo cohort, body composition was assessed by air-displacement plethysmography (ADP) and for the 3-24-month cohort by the deuterium dilution (DD) technique. Fat mass (FM), fat-free mass (FFM), FM index (FMI), and FFM index (FFMI) were calculated. Independent variables comprised the Gini index of the country, maternal and infant characteristics, and breastfeeding pattern at 3 months. For the 3-24-mo cohort, breastfeeding, and minimum dietary diversity (MDD) at 12 months were also included. Crude and adjusted analyses stratified by sex were conducted by multilevel modelling using mixed models.

RESULTS

At 6 months, every 1 kg increase in birth weight was associated with an increase of 0.716 kg in FFM and 0.582 kg/m2 in FFMI in girls, whereas in boys, the increase was of 0.277 kg in FFM. At 24 months, compared to those weaned before 12 months, girls still breastfed at 12 months presented a decrease of 0.225 kg in FM, 0.645 kg in FFM and 0.459 kg/m2 in FFMI, and in boys the decreases were of 0.467 kg in FM, 0.603 kg in FFM and 0.628 kg/m2 in FFMI.

CONCLUSION

Birth weight and breastfeeding are independent predictors of body composition in early life, irrespective of sex.

Family economic trajectories and body mass index in Indonesia: Evidence from the Indonesian Family Life Surveys 2 to 5

Indonesia faces the double burdens of childhood obesity and malnutrition. A family's socioeconomic status has been suggested to be one of the most influential factors contributing to childhood nutritional problems. This study aimed to: 1) identify the distinct trajectories of family economics; and 2) assess whether a family's economic trajectory influences children's body mass index (BMI). We analyzed trajectory patterns of family economic levels from 1997 to 2015 among 846 children aged under 3 years in 1997 using data from Indonesian Family Life Surveys. Trajectory patterns were identified with Group-Based Trajectory Modeling using the traj plug-in in STATA software. The BMI was classified according to 2007 World Health Organization growth standards. Adjusted relative risk ratios (aRRRs) of family economic level trajectories and children's BMI were calculated using multinomial logistic regressions. We identified three distinct trajectories of family economic level: stable poorest, stable middle, and increasing richest. In the total sample, there were no significant relationships between a family's income trajectory and children's BMI in the adjusted models. A significant relationship existed for male children, but not for female children, of compared to the poorest family trajectory group, male children in the increasing richest trajectory group were more likely to be overweight/obese (aRRR 6.1, 95% confidence interval: 1.22-30.62) after adjusting for age and BMI. The present results highlight the importance of early interventions to minimize the potential adverse impacts of excessive BMI later in adulthood.

Growing Up Unequal: Disparities of Childhood Overweight and Obesity in Indonesia's 514 Districts

BACKGROUND

Childhood obesity is a major public health concern as it increases the risk of premature death and adult disability. Globally, the latest estimates showed that more than 340 million children and adolescents between the ages of 5 and 19 were overweight or obese in 2016. This study aimed to investigate the disparities in childhood overweight and obesity across 514 districts in Indonesia, based on geographic and socioeconomic factors.

METHODS

Geospatial and quantitative analyses were performed using the latest Indonesian Basic Health Survey data from 2018. Dependent variables were rates of overweight and obesity among children aged 5-17 years including by gender.

RESULTS

This study found that the rates of overweight were 17.2%, 17.6%, and 16.8% among all children, boys, and girls, while the rates of obesity were 7.0%, 7.9%, and 6.1%, respectively. Boys were 1.30 times more likely to be obese than girls, while overweight was similar between both sexes. Urban cities had significantly higher prevalence of childhood overweight and obesity compared with rural districts by up to 1.26 and 1.32 times, respectively. In addition, the most developed region had significantly higher prevalence of childhood overweight and obesity than the least developed region by up to 1.37 and 1.38 times, respectively. With regard to socioeconomic factors, our analysis demonstrated a notable disparity in the prevalence of childhood overweight and obesity across income quintiles. Specifically, the wealthiest districts exhibited a 1.18 times higher prevalence of overweight and obesity among all children compared with the poorest districts. This association was particularly pronounced among boys; in the richest quintile, the prevalence of overweight and obesity was 1.24 and 1.26 times higher, respectively, in comparison to the poorest income quintile. In contrast, district-level education appears to exhibit an inverse relationship with the prevalence of childhood overweight and obesity, although the findings were not statistically significant.

Independent and Joined Association between Socioeconomic Indicators and Pediatric Obesity in Spain: The PASOS Study

Childhood obesity is a public health problem worldwide. An important determinant of child and adolescent obesity is socioeconomic status (SES). However, the magnitude of the impact of different SES indicators on pediatric obesity on the Spanish population scale is unclear. The aim of this study was to assess the association between three SES indicators and obesity in a nationwide, representative sample of Spanish children and adolescents. A total of 2791 boys and girls aged 8 to 16 years old were included. Their weight, height, and waist circumference were measured. SES was assessed using two parent/legal guardian self-reported indicators (educational level -University/non-University- and labor market status -Employed/Unemployed-). As a third SES indicator, the annual mean income per person was obtained from the census section where the participating schools were located (≥12.731€/<12.731€). The prevalence of obesity, severe obesity, and abdominal obesity was 11.5%, 1.4%, and 22.3%, respectively. Logistic regression models showed an inverse association of both education and labor market status with obesity, severe obesity, and abdominal obesity (all p < 0.001). Income was also inversely associated with obesity (p < 0.01) and abdominal obesity (p < 0.001). Finally, the highest composite SES category (University/Employed/≥12.731€ n = 517) showed a robust and inverse association with obesity (OR = 0.28; 95% CI: 0.16-0.48), severe obesity (OR = 0.20; 95% CI: 0.05-0.81), and abdominal obesity (OR = 0.36; 95% CI: 0.23-0.54) in comparison with the lowest composite SES category (Less than University/Unemployed/<12.731€; n = 164). No significant interaction between composite SES categories and age and gender was found. SES is strongly associated with pediatric obesity in Spain.

Recreational screen time trajectories during early childhood and imaging-measured body composition at age 7 in the Odense child cohort

BACKGROUND

Children spend increasing amounts of time on recreational screen media, which may lead to an obesogenic environment.

OBJECTIVES

We investigated the association of trajectories of screen time across ages 3, 5 and 7 years with body composition at age 7 in the Odense Child Cohort.

METHODS

Data were collected in the Municipality of Odense, Denmark, between 2010 and 2019. Group-based trajectory modelling was applied to group participants into four trajectories of prospective parent-reported screen time. Body composition was assessed using dual-energy x-ray absorptiometry with calculated fat-mass index (FMI) as the primary outcome. Primary models were linear multivariable regression models adjusted for participants' sex, age, birthweight, maternal origin, maternal education, maternal body-mass-index, and maternal age. Further models were adjusted for additional possible confounders. Selection bias was addressed by inverse probability weighting.

RESULTS

In total, 803 children (48.2% female) were included in the primary analysis. Participants with screen time at all time points were assigned to four trajectory groups [constant low screen time (12.7%), low increase (36.3%), high increase between ages 3 and 5 (33.5%) and high increase in screen time (17.5%)]. Sample characteristics differed across missing data status and trajectories. Mean FMI (kg/m² ) and standard deviation (SD) were 3.7 (SD 1.3) and 3.9 (SD 1.6) for the constant low versus high screen time, respectively. No differences in FMI were found between screen time trajectory groups at age 7 (adjusted mean difference 0.1 kg/m² , 95% confidence interval -0.3, 0.5 for constant low versus high screen time). No consistent associations between screen time groups and secondary body composition outcomes were found.

CONCLUSIONS

Results from this study do not suggest that recreational screen time from age 3 to 7 years is associated with adiposity or other measures of body composition.

Individual and Socioeconomic Contextual Factors Associated with Obesity in Brazilian Adolescents: VigiNUTRI Brasil

This study investigated the association of socioeconomic contextual factors of the municipality of residence of adolescents, their eating behavior and food consumption with the prevalence of obesity. This was a cross-sectional study, based on individual data regarding anthropometry, eating behavior (eating in front of screens and having at least three main meals a day), and markers of healthy and unhealthy eating of 23,509 adolescents aged 10 to 19 years, participating in the Food and Nutrition Surveillance of the Brazilian Population monitored in Primary Health Care (VigiNUTRI Brasil) assessment in 2018. Based on multilevel Poisson regression, a higher prevalence of obesity was observed among adolescents living in municipalities with per capita income above USD209.68 (PR = 1.22; 95% CI 1.05;1.42) and among those who consumed hamburgers and/or processed meats the previous day (PR = 1.09; 95% CI 1.01;1.17). Adolescents who had the habit of having three main meals a day (PR = 0.81; 95% CI 0.73;0.89 p < 0.05) and who consumed fresh fruit the previous day (PR = 0.91; 95% CI 0.84;0.98 p < 0.001) had lower prevalence of obesity. The results reinforce the influence of the social context and food consumption on obesity rates. The persistence of this situation implies a worsening in the current and future health of adolescents.

Association between executive function and excess weight in pre-school children

The association between executive function and excess weight is becoming increasingly evident. However, the results of previous studies are still inconclusive, and there is a lack of evidence in early childhood. This study aims to examine the association between executive function, in terms of overall and subscales of executive function (e.g., inhibition, working memory, and shifting), and weight excess in preschoolers. A population-based cross-sectional study was conducted on children aged 2–5 years of age from public and private schools in Chiang Mai, Thailand. Participants’ weights and heights were measured and classified into three weight status groups (i.e., children with normal weight, overweight, and obesity groups). Executive function was assessed using the parent-report Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P). Multivariable polynomial regression was performed to analyze the association between executive function and weight status. A total of 1,181 children were included in the study. After adjusting for confounders, impaired overall executive function significantly increased the probability of being overweight (odds ratio [OR] = 2.47; 95% confidence interval [CI] 1.33 to 4.56). A similar trend of association was also found between impaired inhibition and overweight status (OR = 2.33; 95%CI 1.11 to 4.90). Furthermore, poor working memory was associated with both overweight and obesity (OR = 1.87; 95%CI 1.09 to 3.20 and OR = 1.74; 95%CI 1.09 to 2.78, respectively). Our data suggest that deficits in executive function, particularly inhibition and working memory, are associated with weight excess in preschoolers. Early promotion of executive function may be needed at this developmental age to prevent unhealthy weight status.

Surgery for the treatment of obesity in children and adolescents

BACKGROUND

Child and adolescent overweight and obesity have increased globally and are associated with significant short- and long-term health consequences.

OBJECTIVES

To assess the effects of surgery for treating obesity in childhood and adolescence.

SEARCH METHODS

For this update, we searched Cochrane Central Register of Controlled Trials, MEDLINE, Latin American and Caribbean Health Science Information database (LILACS), World Health Organization International Clinical Trials Registry Platform (ICTRP)and ClinicalTrials.gov on 20 August 2021 (date of the last search for all databases). We did not apply language restrictions. We checked references of identified studies and systematic reviews.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of surgical interventions for treating obesity in children and adolescents (age < 18 years) with a minimum of six months of follow-up. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or which included participants with a secondary or syndromic cause of obesity, or who were pregnant.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently extracted data and assessed the risk of bias using the Cochrane Risk of Bias 2.0 tool. Where necessary, we contacted authors for additional information.

MAIN RESULTS

With this update, we did not find any new RCTs. Therefore, this updated review still includes a single RCT (a total of 50 participants, 25 in both the intervention and comparator groups). The intervention focused on laparoscopic adjustable gastric banding surgery, which was compared to a control group receiving a multi-component lifestyle programme. The participating population consisted of Australian adolescents (a higher proportion of girls than boys) aged 14 to 18 years, with a mean age of 16.5 and 16.6 years in the gastric banding and lifestyle groups, respectively. The trial was conducted in a private hospital, receiving funding from the gastric banding manufacturer. For most of the outcomes, we identified a high risk of bias, mainly due to bias due to missing outcome data. Laparoscopic gastric banding surgery may reduce BMI by a mean difference (MD) of -11.40 kg/m2 (95% CI -13.22 to -9.58) and weight by -31.60 kg (95% CI -36.66 to -26.54) compared to a multi-component lifestyle programme at two years follow-up. The evidence is very uncertain due to serious imprecision and a high risk of bias. Adverse events were reported in 12/25 (48%) participants in the intervention group compared to 11/25 (44%) in the control group. A total of 28% of the adolescents undergoing gastric banding required revisional surgery. The evidence is very uncertain due to serious imprecision and a high risk of bias. At two years of follow-up, laparoscopic gastric banding surgery may increase health-related quality of life in the physical functioning scores by an MD of 16.30 (95% CI 4.90 to 27.70) and change in health scores by an MD of 0.82 (95% CI 0.18 to 1.46) compared to the lifestyle group. The evidence is very uncertain due to serious imprecision and a high risk of bias. No data were reported for all-cause mortality, behaviour change, participants' views of the intervention and socioeconomic effects. Finally, we have identified three ongoing RCTs that are evaluating the efficacy and safety of metabolic and bariatric surgery in children and adolescents.

AUTHORS' CONCLUSIONS

Laparoscopic gastric banding led to greater body weight loss compared to a multi-component lifestyle program in one small study with 50 participants. These results have very limited application, primarily due to more recent recommendations derived from observation studies to avoid the use of banding in youth due to long-term reoperation rates. This systematic review update still highlights the lack of RCTs in this field. The authors are concerned that there may be ethical barriers to RTCs in this field, despite the lack of other effective therapies for severe obesity in children and adolescents and the significant morbidity and premature mortality caused by childhood obesity. Nevertheless, future studies, whether pre-registered and planned non-randomised or pragmatic randomised trials, should assess the impact of the surgical procedure and post-operative care to minimise adverse events, including the need for post-operative adjustments and revisional surgery. Long-term follow-up is also critical to comprehensively assess the impact of surgery as participants enter adulthood.

Sociodemographic and Socioeconomic Factors Influencing the Body Mass Composition of School-Age Children

The purpose of the study was to evaluate the components of overweight, obesity, and body mass components among children aged 7 to 13 years against important sociodemographic factors. The analyses considered 315 school-age children from 7 to 13 years of age (164 boys and 151 girls). Each subject was assessed for body weight and height, body weight category, and main sociodemographic factors. Body mass components of body mass (body-fat percentage (BFP), muscle tissue, fat-free mass (FFM), and total body water (TBW) levels) were evaluated using the electrical bioimpedance method (BIA) and the TANITA 780 MC analyzer. A statistical analysis showed significant differences between the body composition of children living in cities in relation to children living in small towns and villages, and no significant differences were found between the results of children living in small towns and children living in villages. The presence of statistically significant differences between the values of the parameters of body composition of the studied children was demonstrated depending on the level of education of their fathers. The presence of statistically significant relationships between BMI of mothers and BFP of their children (p = 0.003), FFM (p = 0.003), muscle tissue (p = 0.001), and TBW (p = 0.001) has been demonstrated. The higher content of adipose tissue in children is strongly dependent on the higher BMI and body mass category of the mother, as well as the lower level of education of the father. The place of residence also significantly affects both the body fat content and the total body water content of body hydration. Living in the city is associated with better body composition.

Area-level and family-level socioeconomic position and body composition trajectories: longitudinal analysis of the UK Millennium Cohort Study

BACKGROUND

Inequalities in the trajectories of body composition in childhood and adolescence have been infrequently studied. Despite the importance of environmental factors in obesity development, little research has looked at area-level socioeconomic position, independent of family socioeconomic position. We aimed to assess how inequalities in body composition develop with age.

METHODS

The Millennium Cohort Study is a longitudinal study of 19 243 families who had a child born between 2000 and 2002 in the UK. Multilevel growth curve models were applied to examine change in fat mass index (FMI), fat free mass index (FFMI; using the Benn index), and fat mass to fat free mass ratio (FM:FFM), measured using Bioelectrical Impedance Analysis, from ages 7 years to 17 years by the Index of Multiple Deprivation (IMD) and household income at baseline.

FINDINGS

Inequalities in FMI and FM:FFM ratio are evident at age 7 years and widen with age. At age 17 years, adolescents in the most disadvantaged IMD group had FMI 0·57 kg/mB (B=Benn parameter; 95% CI 0·43 to 0·70) higher and FM:FFM ratio 0·037 (95% CI 0·026 to 0·047) higher compared with the most advantaged group. Disadvantaged socioeconomic position is associated with higher FFMI but is reversed in adolescence after adjustment for FMI. Inequalities were greater in girls at age 7 years (mean FMI 0·22 kg/mB; 95% CI 0·13 to 0·32) compared with boys of the same age (0·05 kg/mB; -0·04 to 0·15, p=0·3), but widen fastest in boys, especially for FMI, in which there was over an 11 times increase in the inequality from age 7 years of 0·05kg/mB (95% CI -0·04 to 0·15) to 0·62 kg/mB at 17 years (0·42 to 0·82). Inequalities for the IMD were similar to income, and persisted at age 17 years independent of family socioeconomic position.

INTERPRETATION

Childhood and adolescence is an important period to address inequalities in body composition, as they emerge and widen. Policies should consider FFM as well as FM, and inequalities in the environment.

FUNDING

Medical Research Council, Economic and Social Research Council.