Generation XXI Birth Cohort Research Articles

Parents' perceptions and dissatisfaction with child silhouette: associated factors among 7-year-old children of the Generation XXI birth cohort.

We compared parent's perceived child's silhouette, and investigated predictors of their dissatisfaction. Participants were 4930 mother-child dyads enrolled at a Portuguese birth cohort. Parents' perceptions of child's current and desired silhouette was assessed and dissatisfaction with child's silhouette was defined as the discrepancy between these ratings (current-desired body). Multinomial logistic regressions, adjusted for potential confounders, were performed. Mothers were more dissatisfied with child's silhouette, compared to fathers, in all weight categories. Mothers and fathers of girls were more dissatisfied, preferring thinner silhouettes (OR = 2.77, 95% CI 2.19; 3.51 and OR = 2.08, 95% CI 1.18; 3.66, respectively), compared to parents of boys. Lower birth weight increased maternal desire for a heavier child silhouette. Younger (< 20years) and less educated (≤ 9years of schooling) mothers were more dissatisfied with their child's silhouette, preferring heavier children (OR = 1.65, 95% CI 1.10; 2.48 and OR = 1.73, 95% CI 1.42; 2.09, respectively). Parents' own dissatisfaction was also associated with child's silhouette dissatisfaction. Sociodemographic characteristics and parents' dissatisfaction with their own silhouette influenced their dissatisfaction with child's silhouette and should be considered when developing obesity interventions. Level III, case-control analytic study.

Bidirectional relationships between appetitive behaviours and body mass index in childhood: a cross-lagged analysis in the Generation XXI birth cohort.

Appetitive behaviours have been associated with body mass index (BMI). However, existing data were largely derived from cross-sectional studies and cannot provide insight into the direction of associations. We aimed to explore the bidirectionality of these associations in school-age children. Participants are from the Generation XXI birth cohort, assessed at both 7 and 10years of age (n = 4264; twins excluded). The Children's Eating Behaviour Questionnaire (CEBQ) was used to measure appetitive behaviours (8 subscales). Anthropometrics were measured and WHO BMI z-score was calculated. Cross-lagged analyses were performed to compare the magnitude and direction of the associations (behaviours at 7years to BMI z-score at 10years and the reverse) (covariates: child's sex, physical exercise, maternal age and education; plus BMI z-score at age 7 or, in the reverse direction, the subscale score). In cross-lagged analyses, appetitive behaviours at 10years of age (apart from emotionalundereating) were shown to be reactive to the child BMI z-score at 7years of age. Only slowness in eating was significantly related to subsequent BMI. However, the strongest association was from the child BMI z-score to the behaviour (βstandardized = -0.028 compared with βstandardized = -0.103, likelihood ratio test p < 0.001). BMI at age7 was related to appetitive behaviours at 10years of age, rather than the reverse. This suggests that children with a higher BMI in middle childhood are at increased risk of developing an avid appetite over time.

Early life socioeconomic circumstances and cardiometabolic health in childhood: Evidence from the Generation XXI cohort

Social adversity is thought to become biologically embedded during sensitive periods of development which could set children on a trajectory of increased risk for later diseases. This study estimated the association between early socioeconomic circumstances and cardiometabolic biomarkers during childhood.We analyzed data from 2962 participants in the birth cohort Generation XXI. Early socioeconomic circumstances included parental education and occupation and household income measured at the child's birth; cardiometabolic biomarkers included a set of parameters that were determined at seven and 10years old. The association between early socioeconomic circumstances and cardiometabolic biomarkers in children aged seven and 10years old was estimated using generalized estimating equations.We observed, after adjustment for birth weight, sex, five-a-day fruit and vegetable intake and sedentary activity, that children with low educated mothers presented higher body mass index z-score (β=0.22; 95%CI: 0.12, 0.33), higher waist circumference (β=1.14; 95%CI: 0.55, 1.73) and increased systolic blood pressure z-score (β=0.15; 95%CI: 0.08, 0.22) at the age of seven. At 10years, children with mothers with low education, presented higher body mass index z-score (β =0.32; 95%CI: 0.21, 0.43), higher waist circumference (β=2.79; 95%CI: 1.94, 3.64), increased diastolic blood pressure z-score (β=0.11; 95%CI: 0.06, 0.17) and increased systolic blood pressure s-score (β=0.20; 95%CI: 0.12, 0.28). When repeated measures of cardiometabolic biomarkers were taken into account, the association between socioeconomic circumstances and cardiometabolic biomarkers remained significant.Low socioeconomic circumstances have a possible detrimental effect on children's cardiometabolic health. Thus, socioeconomic adversity might impact health outcomes already in the first decade of life, emphasizing the early social patterning of cardiometabolic health and the need of social policies targeting children and families to modify or reverse its negative impact on health.

Socioeconomic disadvantage and health in early childhood: a population-based birth cohort study from Portugal.

Measuring early socioeconomic inequalities in health provides evidence to understand the patterns of disease. Thus, our aim was to determine which children's health outcomes are patterned by socioeconomics and to what extent the magnitude/direction of the differences vary by socioeconomic measure and outcome. Data on early childhood (4 years) health was obtained from Generation XXI birth cohort (n = 8647). A total of 27 health outcomes and 13 socioeconomic indicators at the individual level and neighbourhood level were used to calculate the relative index of inequality (RII). Socioeconomic inequalities were evident across 21 of the 27 health outcomes. Education, occupation and income more often captured inequalities, compared with neighbourhood deprivation or employment status. Using highest maternal education as reference category, we observed that seizures (RII = 8.64), obesity (2.94), abdominal obesity (2.66), urinary tract infection (2.26), language/speech problems (2.24), hypertension (2.08) and insulin resistance (1.33) were heavily socially patterned, much more common in disadvantaged children. Contrastingly, eczema (0.26) and rhinitis (0.26) were more common among more advantaged children. Socioeconomic inequalities were evident for almost every health outcome assessed, although with varying magnitude/direction according to the socioeconomic indicator and outcome. Our results reinforce that the social gradient in health manifests early in childhood.

Application of the mixture item response theory model to the Self-Administered Food Security Survey Module for Children.

BackgroundThe Self-Administered Food Security Survey Module for Children was developed to assess food insecurity of individual children and has not been used in Portugal. We aimed to apply the mixture item response theory model to the Self-Administered Food Security Survey Module for Children, to assess its reliability and validity, and to estimate the cut-offs of the food security status for Portuguese children.MethodsThe scale was self-administered to 2132 children of the Generation XXI birth cohort. The internal consistency was assessed using Cronbach’s alpha. We evaluated dimensionality and/or clustering, and Latent Class Analysis, Latent Trait Analysis and Mixture Latent Trait Analysis were tested. The number of classes and/or traits were defined according to the Akaike Information Criterion, Bayesian Information Criterion, Adjusted Bayesian Information Criterion, Vuong-Lo-Mendell-Rubin Likelihood Ratio Test, Bootstrapped Likelihood Ratio Test and Entropy. Construct validity was explored using socio-demographic characteristics. The classification tree was used to define cut-offs to predict cluster membership.ResultsThe best model was a Mixture Latent Trait Analysis with 1 factor and 2 classes (food security and food insecurity), assuming class variant item parameters (for items 1 and 3). Based on the estimated posterior probabilities, the food insecurity prevalence was 17.6%. Cronbach’s alpha was 0.617. A higher proportion of less-educated mothers and low-income households was observed in the food insecurity class. The classification tree showed an accuracy of 100.0% by identifying the food security and food insecurity groups.ConclusionOur results supported that the Self-Administered Food Security Survey Module for Children provides a valid and reliable measure, which allows the identification of food insecurity among Portuguese children.

Early socioeconomic circumstances and cardiometabolic health in 10-year-old children

Abstract Background Social adversity is thought to become biologically embedded during sensitive periods of development, setting children on a trajectory of increased risk for later chronic diseases. Thus, social differences are expected to be expressed as biological alterations and might have their origins in early life. Therefore, we aim to estimate the association between early socioeconomic position (SEP) and cardiometabolic health during childhood. Methods Data from 2962 participants in the population-based birth cohort Generation XXI, from Porto, Portugal, was collected following standardized procedures at all study waves. Early SEP definition included household income, parental education and occupation at child’s birth. Cardiometabolic health was characterized at the age of 7 and 10, considering the triglycerides, cholesterol, fasting glucose, body mass index, systolic and diastolic blood pressure. Logistic regression was used to estimate the association between early SEP and a favorable cardiometabolic health profile. Results A favorable cardiometabolic profile was observed in almost half of participants at both ages, particularly among high SEP children who remain more frequently without alterations. For girls, higher paternal education at 7 years (OR:1.49;95%CI:1.03-2.15) and higher SEP at 10 were associated with better cardiometabolic health profile. In boys, a better cardiometabolic health profile was observed with increasing levels in maternal and paternal education and occupation, but at the age of 10, social differences were more evident according to parental education. Conclusions We provide evidence that children from more advantaged SEP at birth have an increased likelihood of presenting better cardiometabolic health at early ages. Social differences in cardiometabolic health biomarkers are already found in childhood, suggesting that the short-term impact of early life SEP on the physiology dysregulation takes place already in the first decade of life. Key messages Social differences in cardiometabolic health are already established in the first decade of life, with children from higher SEP presenting a better cardiometabolic health. Cardiovascular events are not expected to develop during childhood, however the underlying atherosclerotic process might already be in course as social differences appear to widen with age.

Early socioeconomic circumstances and adverse childhood experiences in 10-year-old children

Abstract Background Evidence showed that adverse childhood experiences (ACEs) are associated with the development of disease later in life and premature death. Examining the occurrence of these experiences at early ages would contribute to intervene and therefore to reduce health inequalities. This study aimed to assess the prevalence of ACEs among 10-year-children and to examine its association with early socioeconomic circumstances. Methods At the fourth wave of the population-based birth cohort Generation XXI, from Porto, Portugal, 5153 children completed a self-report questionnaire on 9 experiences related to household dysfunction and physical and emotional abuse. Socioeconomic circumstances included household income, maternal and paternal education, and history of parental unemployment. Logistic regression was performed to calculate the Odds Ratios (OR) and 95% Confidence Intervals (95%CI). Results A high prevalence of physical and emotional abuse was reported by children from low socioeconomic circumstances. A graded relationship between socioeconomic circumstances and cumulative ACEs was observed, for instance, low household income was associated with increased number of ACEs (one event [OR = 1.10; 95%CI: 0.89-1.36], two events [OR = 1.41; 95%CI: 1.15-1.73], three events [OR = 1.67; 95%CI: 1.34-2.06], and four or more events [OR = 2.05; 95%CI: 1.64-2.55]). Also, living with one parent or none of them increased the likelihood of reporting multiple ACEs (OR = 5.50; 95%CI: 4.23-7.13). Conclusions Children from low socioeconomic circumstances were more likely to report multiple adverse experiences in the first decade of life. These findings support that children from less advantaged environments might be at a higher risk of co-occurrence of adverse experiences during their childhood. Key messages Prevalence of ACEs is high among 10-year-old children and is associated with low socioeconomic circumstances. Social inequalities in children should be prioritized by public health policy.

Neighbourhood green space and allostatic load in school-aged children. Findings from the Generation XXI birth cohort.

Neighbourhood green space and allostatic load in school-aged children. Findings from the Generation XXI birth cohort.

Different levels of cardiometabolic indicators in multiple vs. singleton children

BackgroundWe aimed to compare cardiometabolic indicators in singletons and multiples at age 7 and explore the birthweight mediation effect.MethodsWe studied 5431 singletons and 103 sets of multiples from Generation XXI birth cohort. Anthropometric measurements, body composition, and fasting blood samples were obtained. Age- and sex-specific z-scores were calculated (additionally height-specific for blood pressure). Adjusted regression coefficients and respective 95% confidence intervals [β (95%CI)] were computed using path analysis.ResultsMultiples had lower weight [− 0.419 (− 0.616;-0.223)], height [− 0.404 (− 0.594;-0.213)], BMI [− 0.470 (− 0.705;-0.234)], fat mass index [− 0.359 (− 0.565;-0.152)], waist circumference [− 0.342 (− 0.537;-0.147)], and waist-to-height ratio [− 0.165 (− 0.326;-0.003)] z-scores. These results were explained by the indirect effect via birthweight, which was also negative and significant for all the aforementioned cardiometabolic indicators, while no direct effect was present. There were also significant indirect effects regarding fat-free mass index, glucose, insulin, and blood pressure, though the total effects were not significant, due to the balance between direct and indirect effects. The only significant direct effect was regarding diastolic blood pressure [− 0.165 (− 0.302;-0.028)].ConclusionsAt age 7, multiples presented better cardiometabolic indicators explained by lower weight at birth, except for the lower blood pressure which was independent of an effect via birthweight.

Association between neighbourhood green space and biological markers in school-aged children. Findings from the Generation XXI birth cohort

BackgroundThere is considerable literature on the psychological and behavioural benefits of green space. However, less is known about its health-promoting effects, as expressed on biological markers. Additionally, incorporating biomarkers into pediatric research may help elucidate the links between exposures to environmental stressors and lifelong health. ObjectiveTo measure the association between geographical accessibility to green spaces and allostatic load (AL), a measure of biological multi-system dysregulation. MethodsWe used data from 3108 7-year old children enrolled in Generation XXI, a population-based birth cohort from the Porto Metropolitan Area (Portugal). We computed an AL index based on seven biomarkers representing four regulatory systems: immune/inflammatory system (high sensitivity C-reactive protein); metabolic system (high density lipoprotein; total cholesterol; glycated hemoglobin; waist-hip ratio) and cardiovascular system (systolic and diastolic blood pressure). Accessibility to green spaces was calculated using a Geographic Information System and crude and adjusted associations were estimated using mixed-effects regression models. ResultsAmong the 3108 children (51.7% male; mean age 87.3 months), the mean AL index was 0.00 (standard deviation 2.94). Adjusted models showed that having a green space within 400 m and 800 m from the child's school was inversely associated with AL (400 m: beta −0.29 95% CI −0.54 to −0.02; 800 m: −0.29 95% CI −0.51 to −0.07). Also, there was a 12% (0%; 23%) increase in the AL index for every 1 km increase in distance to the nearest green space. No significant associations with AL were observed with residential accessibility to green space or with the presence of a garden at home. ConclusionWe found a cross-sectional negative association between accessibility to green space near schools and AL in children, suggesting that the provision of green space may contribute to improvements in population health beginning early in life.

Association of Pubertal Development With Adiposity and Cardiometabolic Health in Girls and Boys—Findings From the Generation XXI Birth Cohort

PurposeEarly timing of pubertal development is associated with worse cardiometabolic health in adulthood. We aimed to evaluate this association in 10-year-old girls and boys and clarify if it is independent of previous body mass index (BMI). MethodsPubertal development was evaluated through the Tanner scale in 4,548 children from the birth cohort Generation XXI. Data on anthropometrics, body composition, blood pressure, lipid profile, fasting plasma glucose, insulin, homeostatic model assessment–insulin resistance (HOMA-IR), and high-sensitivity C-reactive protein were collected. Bonferroni correction was applied, using an alpha of .004 for statistical significance. Regression coefficients and 99.6% confidence intervals were computed using linear regression models. ResultsGirls with a Tanner stage ≥2 presented statistically significant higher values of BMI, waist circumference (WC), waist-to-height ratio, fat mass index, blood pressure, glucose, insulin, HOMA-IR, triglycerides, and high-sensitivity C-reactive protein and lower values of high-density lipoprotein cholesterol. Boys with a Tanner stage ≥2 presented statistically significant higher values of BMI, WC, systolic blood pressure, and HOMA-IR and lower values of high-density lipoprotein cholesterol. After adjustment, including previous BMI, a Tanner stage ≥2 remained associated with BMI z-score (girls β = .41 [.32, .50]; boys β = .10 [.01, .19]) and WC (girls β = 2.64 cm [1.86, 3.43]; boys β = .81 cm [.11, 1.51]), and only in girls with waist-to-height ratio (β = .01 [.00, .01]), fat mass index (β = .31 kg/m2 [.08; .54]), glucose (β = 1.59 mg/dL [.85, 2.33]), insulin (β = 1.73 μU/mL [.68, 2.78]), and HOMA-IR (β = .40 [.16, .64]). ConclusionsIndependently of previous BMI, preteens with early puberty already had more adiposity at age 10 years. In addition, girls had higher glucose, insulin, and HOMA-IR, which may predict a worse glucose metabolism. These preteens should be a target for public health interventions.

Adherence to a healthy eating index from pre-school to school age and its associations with sociodemographic and early life factors.

Childhood is considered an important period for the development of healthy eating behaviours. This study aimed to evaluate the influence of early life factors and sociodemographic characteristics, including early diet quality, on diet quality at 7 years. The sample includes 5013 children evaluated at the ages of 4 and 7 years from the Portuguese birth cohort Generation XXI with complete information on FFQ. A healthy eating index was developed at both ages to assess adherence to the WHO's dietary recommendations, including eight food groups. Consumption quartiles were obtained for each group at 4 years and assigned a score between 1 and 4. A higher score represents a higher adherence to a better diet (range: 8 to 32). The associations between early life factors and sociodemographic characteristics and the score of the healthy eating index at 7 years were evaluated through linear regression models. The healthy eating index had an average score of 21⋅4 ± 3⋅53 (range: 12 to 32) at 4 years and 20⋅3 ± 3⋅36 (range: 11 to 31) at 7 years. After adjustment for confounders, a positive association was found between the healthy eating index at 4 and 7 years (β = 0⋅384, 95 % CI 0⋅356, 0⋅441). Maternal years of education (β = 0⋅094, 95 % CI 0⋅071, 0⋅116) and dietary score (β = 0⋅182, 95 % CI 0⋅155, 0⋅209) were positively associated with increasing dietary quality from 4 to 7 years. A healthier diet at preschool age, higher maternal education and a healthier diet increase the likelihood of maintaining a high healthy eating index score at school age.

Direct and BMI-mediated effect of birthweight on childhood cardio-metabolic health-a birth cohort study.

Different directions of the association of birthweight with cardio-metabolic health have been found, especially in children, which may be explained by the mediating effect of attained adiposity. We aimed to untangle direct and BMI-mediated associations of birthweight with childhood cardio-metabolic indicators. Children from Generation XXI birth cohort were included (n = 4881). Birthweight was abstracted from clinical files. At age 4 and 7, children were re-evaluated. Glucose, triglycerides, LDL-cholesterol, systolic (SBP) and diastolic blood pressure (DBP) z-scores were the cardio-metabolic traits analyzed. Regression coefficients and respective 95% confidence intervals [β (95%CI)] were computed using path analysis. Birthweight had inverse total effect on SBP at age 4 [-0.005 (-0.010; -0.001)] and 7 [-0.011 (-0.017; -0.006)] and DBP at 7 [-0.008 (-0.012; -0.004)]. Direct effects were found for SBP at 4 [-0.013 (-0.018; -0.009)] and 7 [-0.014 (-0.019; -0.009)], and DBP at 7 [-0.010 (-0.015; -0.006)], explaining the inverse total effects. Positive BMI-mediated indirect effects were found for all cardio-metabolic traits: higher birthweight was associated with higher childhood BMI, which in turn was associated with higher levels of cardio-metabolic traits. Positive BMI-mediated effect of birthweight on all cardio-metabolic traits was found. However, direct effects were in the opposite direction, significant for blood pressure, which may explain the diversity of results observed in the literature. Combining the direct and BMI-mediated effects, higher birthweight was associated with lower blood pressure at age 7 and have no effect on other cardio-metabolic traits.

Early childhood as a sensitive period for the effect of growth on childhood bone mass: Evidence from Generation XXI birth cohort.

To identify sensitive periods for the effect of early life growth on childhood bone mass we compared the associations between weight and length/height velocities from birth to age six and bone mineral content (BMC) and areal density (aBMD) at 7 years of age. We analyzed data from 1853 participants from the Generation XXI birth cohort scanned with a whole body dual-energy X-ray absorptiometry system. Velocities of growth in weight and length/height were obtained through linear spline multilevel models on the basis of data collected during routine health examinations. Using linear regression we computed associations of birth weight, birth length, five weight velocities ("early neonatal": 0-10 days, "early infancy": 10 days-3 months, "late infancy": 3-12 months, "early childhood": 1-3 years, and "later childhood": 3-6 years) and four length/height velocities ("early infancy": 0-3 months, "late infancy": 3-12 months, "early childhood": 1-3 years, and "later childhood": 3-6 years) with outcomes BMC, aBMD, height and height-adjusted BMC at age seven. Confounding by maternal and child characteristics was addressed and effects of growth velocities were adjusted to preceding growth. Weight and length/height velocities up to the age of six were associated with increased bone mass, areal density and height at 7 years with the strongest associations observed for growth in early childhood. In this age period, after concurrent height and confounder adjustment, one standard deviation (SD) increase in weight velocity was associated with higher BMC z-scores: 0.27 (95%CI: 0.22, 0.32) in girls and 0.24 (95%CI: 0.19, 0.29) in boys. Height velocity was also associated with greater height-adjusted BMC z-score: 0.12 (95%CI: 0.07, 0.17) per SD in girls and 0.11 (95%CI: 0.06, 0.16) in boys. The pattern of associations was similar, albeit attenuated, after adjusting for preceding growth. Growth in second and third years of life may represent a sensitive period for the effect of growth on childhood bone mass, partly through their effect on concurrent body size.

Sagittal standing posture and relationships with anthropometrics and body composition during childhood

BackgroundAnthropometry and body composition are plausible influences on pediatric sagittal standing posture. Despite that, the relationship of anthropometrics since birth and body composition with individual postural parameters in children has never been assessed. Research questionTo assess the associations between anthropometrics since birth and body composition parameters, and angles of sagittal standing posture in children. MethodsThe sample included 1021 girls and 1096 boys, evaluated in the population-based birth cohort Generation XXI, Portugal. Weight and height were obtained at birth, 4 and 7 years of age. At age 7, total body less head fat/fat-free mass and bone properties were estimated from whole body dual energy X-ray absorptiometry scans and posture was assessed through right-side photographs during habitual standing with retro-reflective markers placed on body landmarks. ResultsGirls showed increased values of lumbar angle, head and neck flexion, and craniocervical angle with the largest mean (standard deviation) difference in lumbar angle [281.7° (7.4) vs. 276.8° (7.1) in boys, p < 0.001]. In both genders, weight and body mass index were weakly associated with lumbar angle: 0.24 ≥ r ≤ 0.31 in girls and 0.16 ≥ r ≤ 0.26 in boys, all p < 0.001. Fat and fat-free mass and bone mineral density were weakly associated with lumbar angle in both genders. SignificanceOur study showed clear postural heterogeneity between girls and boys in early ages. Lumbar angle is likely to be the single most relevant proxy of overall posture based on the associations with the exposures reported in this study.

Dietary patterns at 7 year-old and their association with cardiometabolic health at 10 year-old

Diet is usually represented as single foods or dietary patterns not related with a specific outcome, and its cardiometabolic effects at early ages are not clearly understood. This study aims to assess whether dietary patterns derived at 7 years of age have an effect on cardiometabolic health at 10 year-old. This study uses data from the Generation XXI birth cohort (northern Portugal, 2005-2006). Dietary data were collected by a validated food frequency questionnaire at 7 year-old and dietary patterns were previously derived through partial least squares (PLS), principal component analysis and latent class analysis. At 10 year-old, systolic (SBP) and diastolic (DBP) blood pressure were measured, and blood samples were drawn to analyze cardiometabolic parameters. Linear regression coefficients and 99% confidence intervals [βˆ(99% CI)] were computed (covariates: birth weight, gestational age, physical activity, maternal age and education) (n=3350). A dietary pattern that explains the BMI z-score at 10 year-old (PLS-1, characterized by the intake of processed meat, energy-dense foods and low in vegetables) was significantly associated with SBP (βˆ=0.052, 99% CI:0.022; 0.082), DBP (βˆ=0.043, 99% CI: 0.022; 0.065), triglycerides (βˆ=0.065, 99% CI: 0.026; 0.104), HDL-cholesterol (βˆ=-0.059, 99% CI:-0.099;-0.019), LDL-cholesterol (βˆ=0.040, 99% CI: 0.001; 0.080) and HOMA-IR (βˆ=0.110, 99% CI: 0.071; 0.149). After further adjustment for BMI at 10 year-old, the magnitude of the associations was weakened. No associations were observed between the other derived dietary patterns and cardiometabolic health. Adherence at 7 years of age to a dietary pattern rich in energy-dense foods, processed meat and low in vegetables, may increase several cardiometabolic parameters at 10 years of age. BMI at 10 year-old explained part of these effects.

Chrono-Nutrition: The Relationship between Time-of-Day Energy and Macronutrient Intake and Children's Body Weight Status.

The time of eating has been considered to have an important role in weight regulation. However, it is unknown if there are specific daily patterns of energy and macronutrient distribution that could be more beneficial for metabolic outcomes, especially obesity. This study aimed to assess the effect of time-of-day energy and macronutrient intake at 4 y of age on the weight status at 7 y of age. The study sample included 1961 children from the population-based birth cohort Generation XXI, with data on 3-day food diaries at 4 y and body mass index (BMI) z-scores at 7 y. Dietary patterns based on the collected data were obtained for the distribution of energy and macronutrients across eating occasions. Having a relatively higher energy intake at lunch and supper (OR = 1.19, 95% CI = 1.05 to 1.34) or at mid-afternoon (OR = 1.18, 95% CI = 1.05 to 1.34) at 4 y was associated with higher odds of becoming overweight/obese at 7 y. A relatively higher intake of fat at lunch was positively associated with later children's odds for being overweight or obese (OR = 1.17, 95% CI = 1.03 to 1.32). These associations were independent of the effect on children's eating behaviors related to appetite. Our results also show a detrimental relation between skipping breakfast and eating late in the day and children's body weight. Considering all daily eating occasions, a higher proportion of energy and macronutrient intake at the main meals and a lower proportion during the afternoon and evening seems to be more beneficial for children's weight. These results emphasize the important role of daily food intake rhythm on excessive weight gain in childhood.

Time trends in prevalence and incidence rates of childhood overweight and obesity in Portugal: Generation XXI birth cohort.

Childhood obesity estimates are steadily increasing worldwide. There is strong evidence that overweight children before puberty maintain this nutritional status for life. This study aimed to estimate the prevalence and incidence rates of overweight and obesity among children recruited as part of the Generation XXI birth cohort. Of the 8036 included children, 5497, 5397 and 4956 of them had follow-up measurements at 4, 7 and 10 years of age, respectively. The chi-square test, Student's t-test, and survival curves were estimated according to sex. The prevalence of overweight remained stable at 4 and 7 years of age (22.0% and 22.1%, respectively) and slightly increased at age 10 (26.1%). Conversely, obesity prevalence increased with age (from 10.6 to 16.8%). Overweight was more prevalent in girls at all follow-ups, whilst obesity was similar between sexes at ages 4 and 7 (p = 0.050 and p = 0.218, respectively) but was more prevalent in boys at age 10 (p = 0.017). The incidence of obesity between 4 and 7 years of age was 11.4/1000 person-years, decreasing to 3.2/1000 person-years between 7 and 10 years of age. Our results reveal a high prevalence/incidence of obesity mainly among 4 and 7-year-old children, heightening the need for interventions at early ages to effectively curb childhood obesity in Portugal.

A Multistate Model for Analyzing Transitions Between Body Mass Index Categories During Childhood: The Generation XXI Birth Cohort Study.

Prevalences of overweight and obesity in young children have risen dramatically in the last several decades in most developed countries. Childhood overweight and obesity are known to have immediate and long-term health consequences and are now recognized as important public health concerns. We used a Markov 4-state model with states defined by 4 body mass index (BMI; weight (kg)/height (m)2) categories (underweight (<-2 standard deviations (SDs) of BMI z score), normal weight (-2 ≤ SD ≤ 1), overweight (1 < SD ≤ 2), and obese (>2 SDs of BMI z score)) to study the rates of transition to higher or lower BMI categories among children aged 4-10 years. We also used this model to study the relationships between explanatory variables and their transition rates. The participants consisted of 4,887 children from the Generation XXI Birth Cohort Study (Porto, Portugal; 2005-2017) who underwent anthropometric evaluation at age 4 years and in at least 1 of the subsequent follow-up waves (ages 7 and 10 years). Children who were normal weight were more likely to move to higher BMI categories than to lower categories, whereas overweight children had similar rates of transition to the 2 adjacent categories. We evaluated the associations of maternal age and education, type of delivery, sex, and birth weight with childhood overweight and obesity, but we observed statistically significant results only for sex and maternal education with regard to the progressive transitions.

Association between eating frequency and eating behaviours related to appetite from 4 to 7 years of age: Findings from the population-based birth cohort generation XXI

The examination of specific characteristics of eating habits in childhood and its influence on eating behaviours is needed to better understand the establishment of appetite-related eating behaviours. This study aimed to assess the association between eating frequency (EF) (main meals vs. snacks) at 4 and 7y and problematic eating behaviours and appetite-related eating behaviours at 7y. The analysis included 1359 children from the birth cohort Generation XXI who provided 3-day food diaries, at both ages, and complete information on the Child Eating Behaviour Questionnaire, at 7y. Problematic eating behaviours were assessed using parental perception of child's poor eating (including not eating enough, eating too slow or overeating) at both ages. A time-of-day approach was used to distinguish main meals from snacks. A cross-lagged analysis was performed to check the direction of the association between EF and parental concerns regarding problematic eating behaviours. Associations between EF and appetite-related eating behaviours were evaluated through linear regression models. Between 4 and 7y a moderate tracking of EF was described as well as a strong tracking of parental concerns. We found a bidirectional relationship between EF and parental concerns. Prospectively, a higher frequency of snacks at 4y was independently associated with higher scores in ‘Desire to Drink’ at 7y (β = 0.051, 95%CI:0.009; 0.093). At 7y, a higher EF had a positive association with ‘Satiety Responsiveness’ but an inverse association with ‘Enjoyment of Food’. A higher number of main meals had a positive association with ‘Enjoyment of Food’ and ‘Food Responsiveness’. In conclusion, children who had more eating occasions seem to have more food-avoidance behaviours, traits that might protect these children from gaining excessive weight.