Genetic and environmental contributions to weight, height, and BMI from birth to 19 years of age: an international study of over 12,000 twin pairs

Meta-Analysis of the Heritability of Childhood Height From 560 000 Pairs of Relatives Born Between 1929 and 2004

BACKGROUND

Childhood height is commonly used to measure children's health and nutritional status. It is used to define stunting, where a child is considered stunted if their height is shorter than two standard deviations below the Child Growth Standards median. Studies have shown that genetic and environmental factors contribute to childhood height, so understanding these contributions is important for stunting research. This systematic review and meta-analysis examined the contribution of these factors across study designs and ancestries.

METHODS

A systematic search found 28 twin and 26 family studies spanning from birth to 17 years. We identified 162 293 twin, 380 195 parent-offspring, and 19 965 sibling pairs born between 1929 and 2004. These datasets were meta-analyzed using a random effects model. The review is registered in PROSPERO (ID CRD42023432550).

RESULTS

The estimated heritability (h 2) of height from twin design increased from birth to 17 years. For children under 5 years, the estimated heritability was 0.57 (95%CI, 0.52-0.61) for European, 0.48 (0.39-0.57) for Asian, and 0.46 (0.40-0.51) for multi ancestries. Heritability estimated from parent-offspring design was 0.46 (95%CI, 0.28-0.62) at birth and 0.76 (95%CI, 0.70-0.80) at 17 years. Meanwhile, the estimated heritability from sibling design remained constant across ages at 0.70 (95%CI, 0.52-0.83).

CONCLUSIONS

The heritability estimates of childhood height were slightly higher in European ancestries, but in general, they did not significantly differ across ancestry groups. While the shared environmental effects on height peak in early childhood, the estimated heritability increase in late teens. Unique environmental factors play a small, but significant role throughout childhood.

Precision medicine to identify, prevent, and treat pediatric obesity

Pediatric obesity is a growing health concern that has many secondary adverse health implications. Personalized medicine is a tool that can be used to optimize diagnosis and treatments of many diseases. In this review, we will focus on three areas related to the genetics of pediatric obesity: (i) genetic causes predisposing to pediatric obesity, (ii) pharmacogenomics that may predict weight gain associated with pharmacotherapy, and (iii) pharmacogenomics of anti-obesity pharmacotherapy. This narrative review evaluates genetic cause of pediatric obesity and how genetic findings can be used to optimize pharmacotherapy to minimize weight gain and optimize obesity treatment in pediatric patients. Pediatric obesity has many genetic causes including genomic obesity syndromes and monogenic obesity disorders. Several genetic etiologies of obesity have current or emerging targeted genetic therapies. Pharmacogenomic (PGx) targets associated with pharmacotherapy-induced weight gain have been identified for antipsychotic, antiepileptic, antidepressant therapies, and steroids, yet to date no clinical guidelines exist for application use of PGx to tailor pharmacotherapy to avoid weight gain. As legislation evolves for genetic testing coverage and technology advances, this will decrease cost and expand access to genetic testing. This will result in identification of potential genetic causes of obesity and genes that predispose to pharmacotherapy-induced weight gain. Advances in precision medicine can ultimately lead to development of clinical practice guidelines on how to apply genetic findings to optimize pharmacotherapy to treat genetic targets of obesity and avoid weight gain as an adverse event associated with pharmacotherapy.

The Correlation of Tooth Sizes and Jaw Dimensions with Biological Sex and Stature in a Contemporary Central European Population

Dental anthropology provides a deep insight into biological, ecological and cultural aspects associated with human individuality, behaviour and living conditions and the environment. Our study uses a correlation analysis to test the metric relationships between tooth sizes and jaw dimensions and juxtaposes them with biological sex and stature. A sample of n = 100 dental casts was used to record metric dental data including the mesio-distal and bucco-lingual tooth crown diameters and nine upper and lower jaw dimensions. All crown diameters were highly correlated with both stature and biological sex, with the canines exhibiting the highest correlation. The majority of jaw dimensions exhibited similar correlations. Our results suggest that the differences between the sexes in most crown diameters and some jaw dimensions may be related to the stature of the individuals measured. Two groups of closely correlating features emerged among the jaw dimensions, differing in their degree of correlation with crown diameters and with sex. The results and insights obtained are highly relevant for evolutionary biology, dentistry, craniofacial research, bioarchaeology and forensic odontology.

The associations between attentional bias to food cues, parent-report appetitive traits, and concurrent adiposity among adolescents

OBJECTIVE

To assess whether attentional bias to food cues and appetitive traits are independently and interactively associated with adiposity in adolescents.

METHOD

Eighty-five adolescents, 14-17-years had their attentional bias to food images measured in a sated state by computing eye tracking measures of attention (first fixation duration, cumulative fixation duration) to food and control distractor images that bordered a computer game. Parents reported adolescent appetitive traits including the food approach domains of enjoyment of food, food responsiveness, emotional overeating, and the food avoidance domains of satiety responsiveness and emotional overeating through the Children's Eating Behavior Questionnaire.

RESULTS

First fixation bias to food cues was positively associated with enjoyment of food, and negatively associated with satiety responsiveness. In a series of regression models adjusted for relevant covariates, first fixation bias to food cues (β = 0.83, p = 0.007), higher food responsiveness (β = 0.74, p < 0.001), higher emotional overeating (β = 0.51, p = 0.002), and a composite appetite score (β = 1.42, p < 0.001) were each significantly associated with greater BMI z-scores. In models assessing the interactive effects between attentional bias and appetitive traits, higher first fixation bias to food cues interacted synergistically with food responsiveness and emotional overeating in relation to BMI z-score. A synergistic interaction between first fixation bias to food cues and the composite appetite score in relation to BMI z-score was also observed.

CONCLUSION

Individuals with high attentional bias to food cues and obesogenic appetitive traits may be particularly susceptible to weight gain.

Longitudinal associations between child discipline methods and physical growth patterns across preschool years

OBJECTIVE

Research has documented the associations of child maltreatment with a range of physical health problems, but little is known about the physical growth patterns of children who experience maltreatment in early childhood. This study aimed to examine the association between various discipline approaches and physical growth in preschool-aged children.

METHODS

In the first year of preschool, parents of 661 Chinese preschool-aged children completed a questionnaire with items pertaining to the frequency of using physical maltreatment, psychological aggression, neglect, and nonviolent discipline toward the child. Children's weight and height were assessed annually using direct assessment in the first and two subsequent years. Longitudinal analyses were performed using multiple regression models.

RESULTS

More frequent neglect and psychological aggression during the first year of preschool were associated with a higher likelihood of a decreased BMI z score in subsequent years. Conversely, increased experience of physical maltreatment in the first year was associated with an increased likelihood of having overweight or obesity in the third year.

CONCLUSIONS

Results indicate that early maltreatment experience can impact physical growth. This highlights the importance of preventing abusive parenting and encouraging healthy habits in young children who have experienced maltreatment to decrease their future risk for weight problems.

Factors Associated with Reaching Mid-Parental Height in Patients Diagnosed with Inflammatory Bowel Disease in Childhood and Adolescent Period

Background/Aims

The recent update on the Selecting Therapeutic Targets in Inflammatory Bowel Disease initiative has added normal growth in children as an intermediate target in Crohn's disease and ulcerative colitis. We aimed to investigate factors associated with reaching mid-parental height (MPH) in patients diagnosed with inflammatory bowel disease in childhood and the adolescent period.

Methods

This multicenter retrospective observational study included pediatric patients with inflammatory bowel disease that had reached adult height. Factors associated with reaching MPH were investigated by logistic regression analyses.

Results

A total of 166 patients were included in this study (128 Crohn's disease and 38 ulcerative colitis). Among them, 54.2% (90/166) had reached their MPH. Multivariable logistic regression analysis revealed that height Z-score at diagnosis and MPH Z-score were independently associated with reaching MPH (odds ratio [OR], 8.45; 95% confidence interval [CI], 4.44 to 17.90; p<0.001 and OR, 0.11; 95% CI, 0.04 to 0.24; p<0.001, respectively). According to the receiver operating characteristic curve analysis, the optimal cutoff level of "height Z-score at diagnosis minus MPH Z-score" that was associated with reaching MPH was -0.01 with an area under the curve of 0.889 (95% CI [0.835 to 0.944], sensitivity 88.9%, specificity 84.2%, positive predictive value 87.0%, negative predictive value 86.5%, p<0.001).

Conclusions

Height Z-score at diagnosis and MPH Z-score were the only factors associated with reaching MPH. Efforts should be made to restore growth in pediatric patients who present with a negative "height Z-score at diagnosis minus MPH Z-score."

The heritability of weight gain in infancy: A population-based twin study

BACKGROUND

Rapid weight gain during infancy is a strong predictor of childhood obesity and is affected by genetic and environmental factors. Identifying ages with low heritability will allow for targeted interventions that might be able to prevent the adverse effects of childhood obesity.

OBJECTIVES

The objective of the study is to estimate the heritability of weight gain from birth to defined ages during infancy, as well as during 6-month periods from birth to 18 months of age. We address this by leveraging large-scale computerised anthropometric data from the state-run network of well-baby clinics in Israel.

METHODS

We performed a population-based twin study. We extracted weight measurements recorded between birth to 24 months from well-baby clinics for 9388 twin pairs born in Israel between 2011 and 2015. The reported sexes of the twins were used as a proxy for their zygosity status. We estimated the heritability of the weight z-score change from birth to specific ages and during particular periods in infancy. To assess the validity of the results, we repeated the analysis in a sub-cohort of twin pairs with complete weight measurements.

RESULTS

During the first 2 years of life, heritability was lowest for birthweight (h 2 = 0.40 ± 0.11 ). Heritability for weight gain since birth was highest at 4 months (h 2 = 0.87 ± 0.13 ), and then gradually decreased until age 18 months (h 2 = 0.62 ± 0.13 ). Estimating the heritability in 6-month intervals from birth to 18 months, heritability was highest during the 6-12-month interval (h 2 = 0.84 ± 0.14 ), and was substantially lower during the subsequent 12-18-month interval (h 2 = 0.43 ± 0.16 ).

CONCLUSIONS

Heritability of weight gain decreases substantially in the second year of life, suggesting that this period could be an appropriate time for interventions for infants who are at an increased risk of childhood obesity.

Better Together: Data Harmonization and Cross-Study Analysis of Abdominal MRI Data From UK Biobank and the German National Cohort

OBJECTIVES

The UK Biobank (UKBB) and German National Cohort (NAKO) are among the largest cohort studies, capturing a wide range of health-related data from the general population, including comprehensive magnetic resonance imaging (MRI) examinations. The purpose of this study was to demonstrate how MRI data from these large-scale studies can be jointly analyzed and to derive comprehensive quantitative image-based phenotypes across the general adult population.

MATERIALS AND METHODS

Image-derived features of abdominal organs (volumes of liver, spleen, kidneys, and pancreas; volumes of kidney hilum adipose tissue; and fat fractions of liver and pancreas) were extracted from T1-weighted Dixon MRI data of 17,996 participants of UKBB and NAKO based on quality-controlled deep learning generated organ segmentations. To enable valid cross-study analysis, we first analyzed the data generating process using methods of causal discovery. We subsequently harmonized data from UKBB and NAKO using the ComBat approach for batch effect correction. We finally performed quantile regression on harmonized data across studies providing quantitative models for the variation of image-derived features stratified for sex and dependent on age, height, and weight.

RESULTS

Data from 8791 UKBB participants (49.9% female; age, 63 ± 7.5 years) and 9205 NAKO participants (49.1% female, age: 51.8 ± 11.4 years) were analyzed. Analysis of the data generating process revealed direct effects of age, sex, height, weight, and the data source (UKBB vs NAKO) on image-derived features. Correction of data source-related effects resulted in markedly improved alignment of image-derived features between UKBB and NAKO. Cross-study analysis on harmonized data revealed comprehensive quantitative models for the phenotypic variation of abdominal organs across the general adult population.

CONCLUSIONS

Cross-study analysis of MRI data from UKBB and NAKO as proposed in this work can be helpful for future joint data analyses across cohorts linking genetic, environmental, and behavioral risk factors to MRI-derived phenotypes and provide reference values for clinical diagnostics.

New insights from GWAS on BMI-related growth traits in a longitudinal cohort of admixed children with Native American and European ancestry

Body-mass index (BMI) is a hallmark of adiposity. In contrast with adulthood, the genetic architecture of BMI during childhood is poorly understood. The few genome-wide association studies (GWAS) on children have been performed almost exclusively in Europeans and at single ages. We performed cross-sectional and longitudinal GWAS for BMI-related traits on 904 admixed children with mostly Mapuche Native American and European ancestries. We found regulatory variants of the immune gene HLA-DQB3 strongly associated with BMI at 1.5 - 2.5 years old. A variant in the sex-determining gene DMRT1 was associated with the age at adiposity rebound (Age-AR) in girls (P = 9.8 × 10 - 9 ). BMI was significantly higher in Mapuche than in Europeans between 5.5 and 16.5 years old. Finally, Age-AR was significantly lower (P = 0.004 ) by 1.94 years and BMI at AR was significantly higher (P = 0.04 ) by 1.2 kg/m 2 , in Mapuche children compared with Europeans.

Forensic application of foot dimensions in ethnic differentiation among Ghanaians

BACKGROUND AND AIM

Foot dimensions are known parameters for height estimation and personal identification in most developed countries but there appears to be dearth of information about their utilization in developing countries. Therefore, the present study sought to provide ethnic-specific baseline data on foot dimensions and bring to light the differences that exist between some ethnic groups in Ghana.

METHODS

One hundred and ninety-three undergraduate students consisting of Ashantis, Fantes and Ewes were recruited.  Plantar surfaces were scanned and foot dimensions were taken.

RESULTS

The left 1st, right 2nd and 3rd toe-pternion lengths and the right breadth at ball were the only dimensions that exhibited differences between the Ashanti and Fante ethnic groups. However, differences were recorded between the Ashanti and Ewe feet for all the measurements taken. Also, with the exception of the right 5th toe-pternion length, all the dimensions exhibited differences.

CONCLUSIONS

Inter-ethnic differences exist for the dimensions of the foot between the ethnic groups that were involved in the present study. The present study has provided ethnic specific baseline data on foot dimensions for identification purposes.

Determining the stability of genome-wide factors in BMI between ages 40 to 69 years

Genome-wide association studies (GWAS) have successfully identified common variants associated with BMI. However, the stability of aggregate genetic variation influencing BMI from midlife and beyond is unknown. By analysing 165,717 men and 193,073 women from the UKBiobank, we performed BMI GWAS on six independent five-year age intervals between 40 and 72 years. We then applied genomic structural equation modeling to test competing hypotheses regarding the stability of genetic effects for BMI. LDSR genetic correlations between BMI assessed between ages 40 to 73 were all very high and ranged 0.89 to 1.00. Genomic structural equation modeling revealed that molecular genetic variance in BMI at each age interval could not be explained by the accumulation of any age-specific genetic influences or autoregressive processes. Instead, a common set of stable genetic influences appears to underpin genome-wide variation in BMI from middle to early old age in men and women alike.

Heritability of Psychological Traits and Developmental Milestones in Infancy: A Systematic Review and Meta-analysis

Importance

Although infancy is the most rapid period of postnatal growth and development, factors associated with variation in infant traits are not well understood.

Objective

To synthesize the large twin study literature partitioning phenotypic variance in psychological traits and developmental milestones in infancy into estimates of heritability and shared and nonshared environment.

Data Sources

PubMed, PsycINFO, and references of included publications were searched up to February 11, 2021.

Study Selection

Peer-reviewed publications using the classical twin design to study psychological traits and developmental milestones from birth to 2 years old were included.

Data Extraction and Synthesis

Data were extracted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and categorized using the International Classification of Functioning, Disability and Health: Children and Youth Version. Data were pooled in 3-level random effects models, incorporating within-cohort variance in outcome measurement and between-cohort variance. Data were analyzed from March 2021 through September 2021.

Main Outcomes and Measures

The primary outcomes were monozygotic and dizygotic twin correlations. These were used to calculate genetic and shared and nonshared environment estimates.

Results

Among 139 publications that were systematically retrieved, data were available on 79 044 twin pairs (31 053 monozygotic and 47 991 dizygotic pairs), 52 independent samples, and 21 countries. Meta-analyses were conducted on psychological traits and developmental milestones from 106 publications organized into 10 categories of functioning, disability, and health. Moderate to high genetic estimates for 8 categories were found, the highest of which was psychomotor functions (pooled h2, 0.59; 95% CI, 0.25-0.79; P < .001). Several categories of traits had substantial shared environment estimates, the highest being mental functions of language (pooled c2, 0.59; 95% CI, 0.24-0.86; P = .001). All examined categories of traits had moderate or high nonshared environment estimates, the highest of which were emotional functions (pooled e2, 0.42; 95% CI, 0.33-0.50; P < .001) and family relationships (pooled e2, 0.42; 95% CI, 0.30-0.55; P < .001).

Conclusions and Relevance

These findings may be an important source of information to guide future gene discovery research, public perspectives on nature and nurture, and clinical insights into the degree to which family history and environments may estimate major domains of infant functioning, disability, and health in psychological traits and developmental milestones.

Your height affects your health: genetic determinants and health-related outcomes in Taiwan

BACKGROUND

Height is an important anthropometric measurement and is associated with many health-related outcomes. Genome-wide association studies (GWASs) have identified hundreds of genetic loci associated with height, mainly in individuals of European ancestry.

METHODS

We performed genome-wide association analyses and replicated previously reported GWAS-determined single nucleotide polymorphisms (SNPs) in the Taiwanese Han population (Taiwan Biobank; n = 67,452). A genetic instrument composed of 251 SNPs was selected from our GWAS, based on height and replication results as the best-fit polygenic risk score (PRS), in accordance with the clumping and p-value threshold method. We also examined the association between genetically determined height (PRS₂₅₁) and measured height (phenotype). We performed observational (phenotype) and genetic PRS₂₅₁ association analyses of height and health-related outcomes.

RESULTS

GWAS identified 6843 SNPs in 89 genomic regions with genome-wide significance, including 18 novel loci. These were the most strongly associated genetic loci (EFEMP1, DIS3L2, ZBTB38, LCORL, HMGA1, CS, and GDF5) previously reported to play a role in height. There was a positive association between PRS₂₅₁ and measured height (p < 0.001). Of the 14 traits and 49 diseases analyzed, we observed significant associations of measured and genetically determined height with only eight traits (p < 0.05/[14 + 49]). Height was positively associated with body weight, waist circumference, and hip circumference but negatively associated with body mass index, waist-hip ratio, body fat, total cholesterol, and low-density lipoprotein cholesterol (p < 0.05/[14 + 49]).

CONCLUSIONS

This study contributes to the understanding of the genetic features of height and health-related outcomes in individuals of Han Chinese ancestry in Taiwan.

Association between CLOCK 3111 T/C polymorphism with ghrelin, GLP-1, food timing, sleep and chronotype in overweight and obese Iranian adults

BACKGROUND

Circadian Locomotor Output Cycles Kaput (CLOCK), an essential element of the positive regulatory arm in the human biological clock, is involved in metabolic regulation. The aim was to investigate the behavioral (sleep duration, food timing, dietary intake, appetite and chronobiologic characteristics) and hormonal (plasma ghrelin and Glucagon-like peptide-1 concentrations) factors that could explain the previously reported association between the CLOCK 3111 T/C SNP and obesity.

METHODS

This cross-sectional study included 403 subjects, overweight and/or obesity, aged 20- 50 years from Iran. The CLOCK rs1801260 data were measured by the PCR-RFLP method. Dietary intake, food timing, sleep duration, appetite and Chrono-type were assessed using validated questionnaires. Ghrelin and GLP-1 were measured by ELIZA in plasma samples. Participants were also divided into three groups based on BMI. Logistic regression models and general linear regression models were used to assess the association between CLOCK genotype and study parameters. Univariate linear regression models were used to assess the interaction between CLOCK and VAS, Food timing, chronotype and sleep on food intakes.

RESULTS

After controlling for confounding factors, there was a significant difference between genotypes for physical activity (P = 0.001), waist circumference (P˂0.05), BMI (˂0.01), weight (P = 0.001), GLP-1 (P = 0.02), ghrelin (P = 0.04), appetite (P˂0.001), chronotype (P˂0.001), sleep (P˂0.001), food timing (P˂0.001), energy (P˂0.05), carbohydrate (P˂0.05) and fat intake (P˂0.001). Our findings also show that people with the minor allele C who ate lunch after 3 PM and breakfast after 9 AM are more prone to obesity (P˂0.05). furthermore, there was significant interactions between C allele carrier group and high appetite on fat intake (Pinteraction = 0.041), eat lunch after 3 PM on energy intake (Pinteraction = 0.039) and morning type on fat intake (Pinteraction = 0.021).

CONCLUSION

Sleep reduction, changes in ghrelin and GLP-1 levels, changes in eating behaviors and evening preference that characterized CLOCK 3111C can all contribute to obesity. Furthermore, the data demonstrate a clear relationship between the timing of food intake and obesity. Our results support the hypothesis that the influence of the CLOCK gene may extend to a wide range of variables related to human behaviors.

Genetic and environmental contributions to variations on appetitive traits at 10 years of age: a twin study within the Generation XXI birth cohort

PURPOSE

Given the variability in adiposity despite ubiquitous exposure to obesogenic food environments, it has been suggested that individuals respond in divergent ways to the environment they live in. The food environment becomes more 'permissive' as children age; therefore, genetic predisposition for a more avid appetite can be better expressed, influencing dietary quality, energy intake and weight gain. Our aim was to explore the genetic and environmental contribution of variations on appetitive traits in a sample of 10-year-old Portuguese children.

METHODS

Participants were twins enrolled in the Generation XXI birth cohort (n = 86 pairs). Parents reported twin's zygosity and child appetitive traits at 10 years of age through the Children's Eating Behavior Questionnaire. Intra-class correlations (ICCs) for all appetitive traits were calculated for monozygotic and dizygotic twins separately to examine patterns of resemblance, and structural equation modeling was conducted aiming to estimate the genetic (A), shared (C) and non-shared (E) environmental variances.

RESULTS

Moderate to strong heritability were found for child appetitive traits, with higher ICCs among monozygotic twin pairs. For all appetitive traits, with the exception of emotional undereating, genetic and non-shared environmental effects contributed to appetite variability. For emotional undereating, environmental effects seem to be more important than genetic effects (C: 0.81; 95% CI 0.71; 0.88 and E: 0.19; 95% CI 0.12; 0.29).

CONCLUSION

There was a significant genetic contribution, followed by non-shared environmental contribution, towards variation in appetitive traits in school-age children. Variation in emotional undereating was primarily explained by shared and non-shared environmental factors.

LEVEL OF EVIDENCE

Evidence obtained from well-designed cohort or case-control analytic studies.

Copy Number Variation Analysis Increases the Number of Candidate Loci Associated with Pediatric Obesity

BACKGROUND/AIMS

Obesity is a multifactorial disease caused by the interaction of genetic, environmental, and behavioral factors. Currently, only a small number of obese children undergo genetic analysis, usually when obesity is associated with dysmorphic features. The aim of this study was to identify genomic rearrangement causing obesity.

METHODS

We analyzed the DNA of children and adolescents by single-nucleotide polymorphism-array (platform CytoScan HD, Affymetrix). Patients included in this study were obese with dysmorphic features and/or intellectual disabilities and/or neuropsychomotor signs.

RESULTS

Ninety-four children and adolescents with obesity (9.25 ± 4.04 years old, 60 males) were enrolled in the study. Dysmorphic features were found in 64 out of 94 subjects (68.1%), intellectual disability was found in 23 subjects (24.5%), and other neuropsychomotor signs in 31 (32.9%). Copy number variations (CNVs) were identified in 43 out of 94 patients (45.7%): among these 14 subjects showed at least 1 deletion, 22 duplication, whereas 7 patients showed both deletion and duplication. In 20 subjects (13 males), CNVs were linked or possibly related with obesity; in 23 subjects, this correlation cannot be inferred.

CONCLUSION

A genetic origin of obesity was detected in about half of our obese children and adolescents with associated dysmorphic features and/or intellectual disability and/or neuropsychomotor signs. In these children, array-CGH analysis can be useful to identify causative genetic mutations, with consequent advantage in therapeutic management and follow-up of these patients.

Testing of a model for risk factors for eating disorders and higher weight among emerging adults: Baseline evaluation

Although a range of risk factors have been identified for disordered eating and weight status, the breadth of risk factors have been rarely considered within a single, comprehensive model. The robustness of these findings across countries also remains an open question. The present study sampled 6272 participants aged 18-30 years from eight countries in an attempt to evaluate combined and unique predictors for these two conditions, and to explore possible cross-country differences in these models. Participants completed a range of demographic, biological, behavioral, psychological, and sociocultural measures to test a comprehensive model of the contributions of these predictors for disordered eating and weight-related constructs (binge eating, body mass index, compensatory behaviors, dietary restraint, drive for muscularity, and drive for leanness). Structural invariance testing within a multigroup path analysis framework revealed that a single model across the eight countries provided poor model fit. Freeing of 22% of parameters across countries provided excellent fit and a satisfactory compromise for country-invariant and country-variant parameters in the model. Overall, predictors accounted for between 15% and 60% of variance in the outcome measures, with lowest explained variance for the disordered eating outcomes. Significant unique contributions to prediction were observed for each of the five risk factor variable types and across the eight countries. Thus, the findings show strong support for this model as an explanatory framework of both disordered eating and weight status.

Understanding the role of village fund and administrative capacity in stunting reduction: Empirical evidence from Indonesia

The Indonesian government launched various programs to handle stunting cases, including village funds. This paper examined the effects of village fund programs and village apparatuses’ capacities to combat stunting based on aggregate data at the district level in Indonesia. Using descriptive data analysis and fixed effect panel regression, we observed that village fund programs could significantly reduce Indonesia’s stunting prevalence, especially outside Java. It also revealed that the increasing education of regional leaders does not necessarily positively impact leaders’ skills in handling stunting. At the same time, the number of village officials has a statistically significant influence on reducing stunting prevalence. It advised that the village budget fund can support national priorities in tackling the prevalence of stunting. Furthermore, it is essential to build the capacity of the village head for increasing awareness of health activities, especially early prevention of stunting, in addition to an adequate number of officials.

Prevalence of Metabolic Syndrome and its Components in Kanifing Municipality, The Gambia

Background

Metabolic syndrome (MetS) is a complex syndrome with clustering of interrelated risk factors for cardiovascular disease and diabetes. Its rising worldwide prevalence has been largely related to the increasing obesity. In The Gambia, the last and only time a MetS related study was conducted, and then reported, was 21 years. Therefore, there is need for evaluating the prevalence of MetS and its components in the country.

Objective

This study was aimed to evaluate the prevalence of MetS and its individual components in Kanifing Municipality (KM).

Methods

It was a cross-sectional study conducted at Kanifing General Hospital, Kanifing Municipality. Data obtained from each participants included anthropometric indices, blood pressure, fasting plasma glucose, triglyceride and high-density lipoprotein levels, and clinical information.

Results

One hundred and thirty-six participants were included in the analysis. The overall MetS prevalence was 54.4% with significant female predominance (female, 58%; male, 29.4%; P=0.025). The most predominant component among the study population was central obesity (raised WC) (72.8%). Hypertriglyceridemia was found to be the strongest predictor of MetS among our participants (OR: 118.13; 95% CI: 33.79-412.77; P < 0.001).

Conclusion

Our study discloses a very high prevalence of MetS among the participants, and a significant female predominance, with central obesity the commonest Mets component. The results suggest that hypertriglyceridemia is the strongest predictor of metabolic syndrome in our study participants.

Estimating heritability in heights without zygosity information for under-five children in low- and middle-income countries: An application of normal finite mixture distribution model

Twin studies are widely used to estimate heritability of traits and typically rely on knowing the zygosity of twin pairs in order to determine variation attributable to genetics. Most twin studies are conducted in high resource settings. Large scale household survey data, such as the Demographic and Health Surveys, collect various biomarkers for children under five years old in low- and middle-income countries. These data include twins but no information on zygosity. We applied mixture models to obtain heritability estimates without knowing zygosity of twins, using 249 Demographic and Health Surveys from 79 low- and middle-income countries (14,524 twin pairs). We focused on height of children, adjusted for age and sex, but also provided estimates for other biomarkers available in the data. We estimated that the heritability of height in our sample was 46%.

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Mixture model was used to obtain heritability estimates for biomarkers for children under five without zygosity information.

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46% of height was determined by heritability.

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Heritability estimate was 0.54 for weight-for-age z-score and 0.51 for residualized weight.

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An implausible heritability estimate of 0.93 was found for weight-for-height z-score.

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Birthweight had a heritability estimate of 0.71 and hemoglobin level had a heritability estimate of 0.61.

Impact of maternal gestational weight gain in twin pregnancies on early childhood obesity risk: A longitudinal birth cohort study

OBJECTIVES

To investigate the impact of gestational weight gain (GWG) on the body mass index-for-age z score (BAZ) and obesity risk among twin offspring.

METHODS

This study included 263 women who were pregnant with twins and their offspring. Maternal GWG was measured in each trimester, and infant weight and length were measured at 6, 12, and 24 months.

RESULTS

Total GWG was positively correlated with offspring birthweight and BAZ at 6, 12 and 24 months [adjusted β 0.013 (95% CI: 0.008-0.019), 0.028 (95% CI: 0.005-0.050), 0.033 (95% CI: 0.010-0.056) and 0.025 (95% CI: 0.004-0.047), respectively]. Excessive total GWG was related to an increased relative risk (RR) of large for gestational age (LGA) and overweight at 6 and 12 months. Only the second trimester gestational weight gain rate (GWGR) was positively correlated with birthweight (adjusted β 0.380, 95% CI: 0.256-0.504), and RRs of 6.818 (95% CI: 1.568-29.642) and 2.852 (95% CI: 1.466-5.548) were found for LGA and overweight at 12 months, respectively.

CONCLUSIONS

Total GWG and the second trimester GWGR were correlated with BAZ and overweight/obesity risk in twin offspring; the impact was obvious in the first year of life and gradually disappeared over time.

CLINICAL TRIAL REGISTRATION

ChiCTR-OOC-16008203, Registered on 1 April 2016 at the Chinese Clinical Trial Registry.

Association between socioeconomic and nutritional factors and height of Brazilian adolescents: results from the Study of Cardiovascular Risk in Adolescents

This study aims to describe the mean height of adolescents from the five regions of Brazil and to evaluate socioeconomic and nutritional factors associated with normal growth. This is a cross-sectional study conducted in the Brazilian urban and rural areas with students aged 12 to 17 years (n = 71,553). Anthropometry, socioeconomic variables, physical activity, and diet were evaluated. Height-for-age z-scores were calculated and multiple linear regression models were used to investigate the association of exposure variables with height (outcome) by sex and age (12-13, 14-15, and 16-17 years). We observed a lower mean height in adolescents from the North Region and in individuals with low socioeconomic status. At 17 years of age, the closest to the final height in this sample, mean heights for girls and boys were 160.9 ± 0.1cm and 173.7 ± 0.3cm, respectively. In multiple linear regression analysis, physical activity (girls β = 0.119, 95%CI: 0.035; 0.202; boys β = 0.092, 95%CI: 0.012; 0.172) and high level of maternal education (girls β = 0.103, 95%CI: 0.001; 0.204; boys β = 0.39, 95%CI: 0.245; 0.534) were positively associated with height-for-age z-score in 16- to 17-year-old boys and girls. Other factors positively associated with height-for-age z-score in older students include higher protein consumption (β = 0.022, 95%CI: 0.010; 0.035) and obesity (β = 0.217, 95%CI: 0.084; 0.350) for boys, and low weight (β = 0.205, 95%CI: 0.028, 0.382) for girls. We observed differences in the mean height among adolescents from the five Brazilian regions. Normal growth, especially among older adolescents, was associated with high maternal education, practice of physical activity, protein consumption, and body mass index (BMI) categories.

Birth weight, adult weight, and cardiovascular biomarkers: Evidence from the Cardiovascular Young Finns Study

This study quantifies the causal effect of birth weight on cardiovascular biomarkers in adulthood using the Cardiovascular Risk in Young Finns Study (YFS). We apply a multivariable Mendelian randomization (MVMR) method that provides a novel approach to improve inference in causal analysis based on a mediation framework. The results show that birth weight is linked to triglyceride levels (β = -0.294; 95% CI [-0.591, 0.003]) but not to low-density lipoprotein (LDL) cholesterol levels (β = 0.007; 95% CI [-0.168, 0.183]). The total effect of birth weight on triglyceride levels is partly offset by a mediation pathway linking birth weight to adult BMI (β = 0.111; 95% CI [-0.013, 0.234]). The negative total effect is consistent with the fetal programming hypothesis. The positive indirect effect via adult BMI highlights the persistence of body weight throughout a person's life and the adverse effects of high BMI on health. The results are consistent with previous findings that both low birth weight and weight gain increase health risks in adulthood.

Thinness, overweight, and obesity in 6- to 9-year-old children from 36 countries: The World Health Organization European Childhood Obesity Surveillance Initiative-COSI 2015-2017

In 2015-2017, the fourth round of the World Health Organization (WHO) European Childhood Obesity Surveillance Initiative (COSI) was conducted in 36 countries. National representative samples of children aged 6-9 (203,323) were measured by trained staff, with similar equipment and using a standardized protocol. This paper assesses the children's body weight status and compares the burden of childhood overweight, obesity, and thinness in Northern, Eastern, and Southern Europe and Central Asia. The results show great geographic variability in height, weight, and body mass index. On average, the children of Northern Europe were the tallest, those of Southern Europe the heaviest, and the children living in Central Asia the lightest and the shortest. Overall, 28.7% of boys and 26.5% of girls were overweight (including obesity) and 2.5% and 1.9%, respectively, were thin according to the WHO definitions. The prevalence of obesity varied from 1.8% of boys and 1.1% of girls in Tajikistan to 21.5% and 19.2%, respectively, in Cyprus, and tended to be higher for boys than for girls. Levels of thinness, stunting, and underweight were relatively low, except in Eastern Europe (for thinness) and in Central Asia. Despite the efforts to halt it, unhealthy weight status is still an important problem in the WHO European Region.

Caregivers' Knowledge and Food Accessibility Contributes to Childhood Malnutrition: A Case Study of Dora Nginza Hospital, South Africa

Amongst the problems facing South Africa today are malnutrition and food insecurity, and there is a need for interventions and innovative strategies to address these. The aim of the study was to determine the contribution of caregivers’ knowledge of nutrition and household food security among children aged 0 to 60 months. A cross-sectional study design was applied using a quantitative approach. A convenience sample (n = 184) of caregiver–child pairs (for children 0 to 60 months) from the Dora Nginza Hospital Paediatric Outpatient Department was used. A structured questionnaire was applied to collect data on socio-economic factors, health status, household food security, and caregivers’ knowledge. In addition, interviews were conducted, and anthropometric measurements of children were taken to determine their nutritional status. The results indicate that most caregivers were female, and more than half completed high school, yet almost 75% were unemployed. Most of the caregivers (58.2%) were either overweight or obese. The results also show that only 33.2% of households were food secure, 29.3% were at risk of hunger, and 37.5% experienced hunger. The prevalence of stunting, underweight, and wasting among children in the study was high. A significant, slightly positive correlation was found between the body mass index of the caregiver and height for age. Poor socio-economic status and food inaccessibility were identified as possible underlying contributing factors to malnutrition, contributing to food insecurity and therefore poor dietary intake.

Genome-wide analysis in Drosophila reveals diet-by-gene interactions and uncovers diet-responsive genes

Genetic and environmental factors play a major role in metabolic health. However, they do not act in isolation, as a change in an environmental factor such as diet may exert different effects based on an individual’s genotype. Here, we sought to understand how such gene–diet interactions influenced nutrient storage and utilization, a major determinant of metabolic disease. We subjected 178 inbred strains from the Drosophila genetic reference panel (DGRP) to diets varying in sugar, fat, and protein. We assessed starvation resistance, a holistic phenotype of nutrient storage and utilization that can be robustly measured. Diet influenced the starvation resistance of most strains, but the effect varied markedly between strains such that some displayed better survival on a high carbohydrate diet (HCD) compared to a high-fat diet while others had opposing responses, illustrating a considerable gene × diet interaction. This demonstrates that genetics plays a major role in diet responses. Furthermore, heritability analysis revealed that the greatest genetic variability arose from diets either high in sugar or high in protein. To uncover the genetic variants that contribute to the heterogeneity in starvation resistance, we mapped 566 diet-responsive SNPs in 293 genes, 174 of which have human orthologs. Using whole-body knockdown, we identified two genes that were required for glucose tolerance, storage, and utilization. Strikingly, flies in which the expression of one of these genes, CG4607 a putative homolog of a mammalian glucose transporter, was reduced at the whole-body level, displayed lethality on a HCD. This study provides evidence that there is a strong interplay between diet and genetics in governing survival in response to starvation, a surrogate measure of nutrient storage efficiency and obesity. It is likely that a similar principle applies to higher organisms thus supporting the case for nutrigenomics as an important health strategy.

Executive Functions in Social Context: Implications for Conceptualizing, Measuring, and Supporting Developmental Trajectories

Success in life is linked to executive functions, a collection of cognitive processes that support goal-directed behaviors. Executive functions is an umbrella term related to cognitive control, self-control, and more. Variations in executive functioning predict concurrent success in schooling, relationships, and behavior, as well as important life outcomes years later. Such findings may suggest that certain individuals are destined for good executive functioning and success. However, environmental influences on executive function and development have long been recognized. Recent research in this tradition demonstrates the power of social contextual influences on children's engagement of executive functions. Such findings suggest new interpretations of why individuals differ in executive functioning and associated life outcomes, including across cultures and socioeconomic statuses. These findings raise fundamental questions about how best to conceptualize, measure, and support executive functioning across diverse contexts. Future research addressing real-world dynamics and computational mechanisms will elucidate how executive functioning emerges in the world.

Birth weight and adult income: An examination of mediation through adult height and body mass

This paper examines the causal links between early human endowments and socioeconomic outcomes in adulthood. We use a genotyped longitudinal survey (Cardiovascular Risk in Young Finns Study) that is linked to the administrative registers of Statistics Finland. We focus on the effect of birth weight on income via two anthropometric mediators: body mass index (BMI) and height in adulthood. We find that (i) the genetic instruments for birth weight, adult height, and adult BMI are statistically powerful; (ii) there is a robust total effect of birth weight on income for men but not for women; (iii) the total effect of birth weight on income for men is partly mediated via height but not via BMI; and (iv) the share of the total effect mediated via height is substantial, of approximately 56%.

Interaction between the genetic variant of rs696217-ghrelin and food intake and obesity and dyslipidemia

In this study, we aimed to investigate the relationship between the genetic variant of rs696217-ghrelin and fasted lipid profile, indices of obesity, and environmental parameters. Amplification refractory mutation system-polymerase chain reaction (ARMs-PCR) was used for genotyping 1118 individuals recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) cohort study. The interaction between the presence of the genetic variant of rs696217-ghrelin and nutritional intake and other major determinants of obesity and lipid profile was examined in the MASHAD study population. Individuals with the TT genotype at the locus had the lowest prevalence of obesity compared to other genotypes among the individuals. No significant relationship was found between the two groups regarding the lipid profile and TT genotype. Furthermore, no significant association was found between dietary intake and the genetic variant of rs696217-ghrelin in the population under study. Individuals with a TT or GT genotype appear to be at a higher risk of obesity, compared to those with a GG genotype. The results of the current study revealed a significant association between the genetic variant of rs696217-ghrelin and obesity; however, this gene did not correlate with the risk factors of cardiovascular diseases and dyslipidemia in the Iranian population.

Effects of parental stature on child stunting in India

Adult heights in India are short. Child stunting remains high though the prevalence fell from 48% to 38% in the decade prior to 2016. This study assesses the links between parental height and child stunting using nationally representative data on 28,975 under-five-year-old children from the 2015-16 National Family Health Survey. Parental heights are represented as quintiles. Logistic regression was applied to estimate the effect of parental heights after adjustment for household wealth, parental schooling, place of residence and other covariates. The unadjusted estimates showed the effect on stunting to be similar for maternal height, wealth and education. In the multivariate analysis maternal height emerged as the strongest predictor of stunting, with adjusted odds of 2.85 for the shortest compared with the tallest quintile. The two other strong predictors of stunting were paternal height and wealth, with adjusted odds of close to 2.0 for the lowest quintile relative to the highest quintiles. In comparison, associations between stunting and other factors were minor, with the partial exception of mother's education. The findings underscore the key role of intergenerational influences on stunting. Maternal height has a stronger association with childhood stunting than paternal height and socioeconomic influences such as education and household wealth. The influence of paternal height is also strong, equal in magnitude to household wealth. Health workers need to be alerted to the special needs of short women.

Early childhood growth trajectory and later cognitive ability: evidence from a large prospective birth cohort of healthy term-born children

BACKGROUND

Most studies of associations between child growth and cognitive ability were based on size at one or two ages and a single measure of cognition. We aimed to characterize different aspects of early growth and their associations with cognitive outcomes in childhood through adolescence.

METHODS

In a sample of 12 368 Belarusian children born at term, we examined associations of length/height and weight trajectories over the first 6.5 years of life with cognitive ability at 6.5 and 16 years and its change over time. We estimated growth trajectories using two random-effects models-the SuperImposition by Translation and Rotation to model overall patterns of growth and the Jenss-Bayley to distinguish growth in infancy from post infancy. Cognitive ability was measured using the Wechsler Abbreviated Scales of Intelligence at 6.5 years and the computerized NeuroTrax test at 16 years.

RESULTS

Higher length/height between birth and 6.5 years was associated with higher cognitive scores at 6.5 and 16 years {2.7 points [95% confidence interval (CI): 2.1, 3.2] and 2.5 points [95% CI: 1.9, 3.0], respectively, per standard deviation [SD] increase}. A 1-SD delay in the childhood height-growth spurt was negatively associated with cognitive scores [-2.4 (95% CI: -3.0, -1.8) at age 6.5; -2.2 (95% CI: -2.7, -1.6) at 16 years]. Birth size and post-infancy growth velocity were positively associated with cognitive scores at both ages. Height trajectories were not associated with the change in cognitive score. Similar results were observed for weight trajectories.

CONCLUSIONS

Among term infants, the overall size, timing of the childhood growth spurt, size at birth and post-infancy growth velocity were all associated with cognitive ability at early-school age and adolescence.

Paleopathological diagnosis of a proportionate short stature on a female skeleton from the Coimbra collection: Turner syndrome versus other causes

OBJECTIVE

This paper discusses the possible etiologies for the proportionate short stature of a female individual and provides data to allow the diagnosis of future cases of Turner Syndrome (TS) in paleopathology.

MATERIALS

Skeleton of a 26-years-old maid, from the Coimbra Identified Skeletal Collection, who died of measles in 1920.

METHODS

Macroscopic examination, imaging techniques, and metric analysis.

RESULTS

Her estimated height is 138.91-144.3 cm, approximately three standard deviations below the average female stature for early 20th century Portugal. The crural, brachial, humero-femoral, and intermembral indexes show a proportionate body, uncommon in dwarfism. Small skull with prominent frontal, maxillary prognathism, enamel hypoplasia, cribra orbitalia, porotic hyperostosis, proliferative reaction in the petrous portion of the temporal, obliterated sagittal suture, oval foramen magnum, and small mandible with masculine features. The sternal ends of the ribs are wider and vertebrae present developmental defects (e.g. atlas with both left transverse foramina and posterior tubercle open, absence of the right transverse foramen in the axis, sacrum with six vertebrae).

CONCLUSIONS

The differential diagnosis point to a possible case of Turner Syndrome.

SIGNIFICANCE

This study describes the features of Turner Syndrome and provide detail metric analysis of this individual, which will be useful for future paleopathological diagnoses.

LIMITATIONS

The confirmation of the diagnosis will only be possible through genetic analysis.

SUGGESTIONS FOR FURTHER RESEARCH

Reanalysis of skeletal individuals with short stature to detect possible cases of Turner Syndrome.

Secular Change in Body Size and Somatotype of Indonesian Children aged 7–15 Years (1999–2019)

BACKGROUND: Secular changes assessment can help identifying the quality of health, wealth, and nutrition among populations and provide suggestions for policymakers. AIM: To examine the secular changes in weight, height, body mass index, and somatotype in Indonesian children between 1999 and 2019. METHODS: This cross-sectional study was conducted in 1999 and 2019 on 2021 children aged 7–15 years in Yogyakarta, Indonesia. Anthropometric measurements including height, weight, humerus and femur breadths, circumferences of upper arm and calf; skinfold thickness of triceps, subscapular, suprailiac, and calf were measured. Body mass index (BMI) was calculated as kg/m2. Somatotype components were defined by the Carter-Heath method. Statistical analyses used were three-ways ANOVA and least significant difference post hoc tests. RESULTS: Significant differences for boys and girls were found for height, weight, BMI, and three components of somatotype across the 2-time points. The boys in period 2019 were the tallest and girls were the heaviest, and for BMI, the highest value was observed in 2019 (girls). The children in the 1999 period had somatotype values 3.3 - 3.3 - 3.7 (boys) and 3.9 - 3.0 - 3.5 (girls), while in the 2019 period the somatotype values for boys were 3.5 - 4.5 - 3.0 and 4.3 - 4.1 - 2.4 for girls. CONCLUSION: In general, based on the order of age, there is a similar pattern between children in the two periods. Among Indonesian children from 1999 to 2019, there were positive trends in weight, BMI, endomorph, and mesomorph components, whereas a negative trend for the ectomorph component.

Factors Associated with Exposure to Dietary Bisphenols in Adolescents

Obesogenic endocrine-disrupting chemicals, such as bisphenol A (BPA) and its analogue bisphenol S (BPS), seem to play an important role in the development of obesity, although contradictory results have been reported. The aim of the present study was to conduct a gender analysis of the factors associated with exposure to dietary bisphenols in 585 Spanish adolescents. Dietary BPA and BPS exposure was assessed using a food frequency questionnaire. Foods and macronutrients accounting for more than 95% of energy intake were selected for analysis. Stepwise regression was used to estimate the foods that most contributed to dietary bisphenol exposure in the sample. Gender-related factors associated with greater dietary bisphenol exposure were evaluated using multivariate logistic regression models. Canned tuna was the main dietary source of BPA and BPS in both adolescent boys and girls. Overweight/obese girls showed a higher risk of high dietary exposure to BPA (odds ratio (OR): 3.38, 95% confidence interval (CI): 1.25-9.07) and total bisphenols (OR: 2.81, 95% CI: 1.03-7.67) in comparison with girls with a BMI lower than 25 kg/m². Present results indicate a positive association of dietary exposure to both total bisphenols and BPA with being overweight/obese in adolescent girls.

A Causal Estimate of Long-Term Health Care Spending Attributable to Body Mass Index Among Adults

While high body mass index (BMI) is believed to be a major driver of poor health, there is little evidence about whether it leads to higher health care spending. Understanding the causal contribution of BMI to health care spending is necessary to estimate the returns to investment in weight loss efforts. We exploit genetic variation in BMI across siblings as a natural experiment to estimate the impact of BMI on cumulative third party and out-of-pocket health care spending among adults using the Panel Study of Income Dynamics data from 1999 through 2011. We estimate a two-stage residual inclusion model with a generalized linear model. We find a $611.60 increase in cumulative insurer spending for each one-unit increase in BMI. This amounts to $130.49 in mean annual spending, and is two times higher than the non-causal estimate. We find no difference in out-of-pocket spending by BMI. These findings suggest that having a higher BMI in young/middle adulthood leads to significantly higher insurer health expenditures over the life course, which can help to inform public and private insurer policies on BMI reduction and control.

Genetics of Obesity: What We Have Learned Over Decades of Research

There is a genetic component to human obesity that accounts for 40% to 50% of the variability in body weight status but that is lower among normal weight individuals (about 30%) and substantially higher in the subpopulation of individuals with obesity and severe obesity (about 60%-80%). The appreciation that heritability varies across classes of BMI represents an important advance. After controlling for BMI, ectopic fat and fat distribution traits are characterized by heritability levels ranging from 30% to 55%. Defects in at least 15 genes are the cause of monogenic obesity cases, resulting mostly from deficiencies in the leptin-melanocortin signaling pathway. Approximately two-thirds of the BMI heritability can be imputed to common DNA variants, whereas low-frequency and rare variants explain the remaining fraction. Diminishing allele effect size is observed as the number of obesity-associated variants expands, with most BMI-increasing or -decreasing alleles contributing only a few grams or less to body weight. Obesity-promoting alleles exert minimal effects in normal weight individuals but have larger effects in individuals with a proneness to obesity, suggesting a higher penetrance; however, it is not known whether these larger effect sizes precede obesity or are caused by an obese state. The obesity genetic risk is conditioned by thousands of DNA variants that make genetically based obesity prevention and treatment a major challenge.

First growth reference curves for Tunisian children and adolescents

A growth chart is a powerful graphical tool displaying children's growth patterns. The aim of this study was to develop growth reference curves appropriate for Tunisian children. The collection of data from this cross-sectional study was conducted on 4358 healthy subjects (2182 girls and 2176 boys) in three pediatric centers and 15 schools. Smoothed growth curves were estimated using the LMS method. The smoothed percentile curves for height, weight, sitting height (SH), and leg length (LL) increase rapidly during the 1st years of life and then progress slowly until 18 years. However, the sitting height-to-height ratio (SHTHR) curves decrease sharply before the age of 4 and then stabilize in both sexes. In addition, the comparison between boys and girls indicated that the values are very similar at most ages. Except during puberty, the values in boys increase (P<0.0001) for the weight, height, SH, and LL parameters and decline (P<0.0001) in the SHTHR compared to the values in girls. The growth rate curves presented two remarkable velocity peaks: the first appears during the 1st years of life and the second at puberty. Height gains at the last stage of growth (puberty) are around 15.45% of final height for boys and 15.52% for girls. This study showed a number of discrepancies for certain age groups when comparing the median weight and height values with those of the World Health Organization, the National Center for Health Statistics, and Algerian references in both sexes. Conclusion: The smoothed percentile curves for weight and height will be useful to access the general growth of Tunisian children. Furthermore, the SH, LL, and SHTHR curves can be used to monitor body proportions during childhood.

Examining the relationship between weight controllability beliefs and eating behaviors: The role of internalized weight stigma and BMI

Body weight is often viewed as personally controllable. This belief, however, ignores the complex etiology of body weight. While such attributions of personal willpower may help some individuals regulate their eating patterns, they have also been associated with increased internalized weight stigma which, itself, is associated with more disinhibited eating. The current investigation aimed to examine how internalized weight stigma, along with BMI, may explain the effect of weight controllability beliefs on disparate dietary behaviors. A community sample of 2702 U.S. adults completed an online survey about their weight controllability beliefs, eating behaviors, and internalized weight stigma, as well as demographic items and self-reported BMI. Results showed that greater weight controllability beliefs were positively related to both more restricted eating, β = 0.135, p < .001, and more disinhibited eating, β = 0.123, p < .001. This ironic effect was partially explained by increased internalized weight stigma. Moreover, BMI moderated the relationship, such that individuals with lower weights demonstrated stronger effects for two of the three eating outcomes than those with higher weights. These findings advance our understanding of the relationship between attributions of personal control for body weight and subsequent health behaviors, and further underscore the need to target internalized weight stigma in dietary interventions.

The effect of a natural disaster on handgrip strength in prepubertal Indian children exposed to a severe cyclone during the prenatal and early postnatal growth

Natural disasters (NDs) experienced by women and their children during prenatal and infant growth may have long-lasting effects on offspring’s development. Handgrip strength (HGS) is one of the measures of muscular strength and an indicator of health status. This study compared HGS in children exposed to cyclone Aila in India during their prenatal and infant growth compared to a control group from a non-affected, adjacent area. The total sample involved 444 boys and 423 girls aged 7–9 years, categorised into 3 groups: prenatally exposed to Aila, exposed to Aila in infancy, and the control group, non-exposed to Aila. Results revealed that prenatally exposed children of both sexes had significantly lower HGS than the controls (at least, p < 0.001 in boys; p < 0.05 in girls). On the other hand, the postnatally exposed boys, but not the girls, showed lower HGS than the controls. A significant effect of a group factor (ND exposure) on HGS was observed even after controlling for confounding variables (age, height, BMI, birth weight, gestational age; at least, p < 0.05). Our findings indicate that prenatal or early postnatal experience of a ND may have association with impaired HGS in prepubertal children.

GWAS reveal a role for the central nervous system in regulating weight and weight change in response to exercise

Body size and weight show considerable variation both within and between species. This variation is controlled in part by genetics, but also strongly influenced by environmental factors including diet and the level of activity experienced by the individual. Due to the increasing obesity epidemic in much of the world, there is considerable interest in the genetic factors that control body weight and how weight changes in response to exercise treatments. Here, we address this question in the Drosophila model system, utilizing 38 strains of the Drosophila Genetics Reference Panel. We use GWAS to identify the molecular pathways that control weight and weight changes in response to exercise. We find that there is a complex set of molecular pathways controlling weight, with many genes linked to the central nervous system (CNS). The CNS also plays a role in the weight change with exercise, in particular, signaling from the CNS. Additional analyses revealed that weight in Drosophila is driven by two factors, animal size, and body composition, as the amount of fat mass versus lean mass impacts the density. Thus, while the CNS appears to be important for weight and exercise-induced weight change, signaling pathways are particularly important for determining how exercise impacts weight.

Global, regional and national epidemiology and prevalence of child stunting, wasting and underweight in low- and middle-income countries, 2006-2018

In 2016, undernutrition, as manifested in childhood stunting, wasting, and underweight were estimated to cause over 1.0 million deaths, 3.9% of years of life lost, and 3.8% of disability-adjusted life years globally. The objective of this study is to estimate the prevalence of undernutrition in low- and middle-income countries (LMICs) using the 2006-2018 cross-sectional nationally representative demographic and health surveys (DHS) data and to explore the sources of regional variations. Anthropometric measurements of children 0-59 months of age from DHS in 62 LMICs worldwide were used. Complete information was available for height-for-age (n = 624,734), weight-for-height (n = 625,230) and weight-for-age (n = 626,130). Random-effects models were fit to estimate the pooled prevalence of stunting, wasting, and underweight. Sources of heterogeneity in the prevalence estimates were explored through subgroup meta-analyses and meta-regression using generalized linear mixed-effects models. Human development index (a country-specific composite index based on life expectancy, literacy, access to education and per capita gross domestic product) and the United Nations region were explored as potential sources of variation in undernutrition. The overall prevalence was 29.1% (95% CI 26.7%, 31.6%) for stunting, 6.3% (95% CI 4.6%, 8.2%) for wasting, and 13.7% (95% CI 10.9%, 16.9%) for underweight. Subgroup analyses suggested that Western Africa, Southern Asia, and Southeastern Asia had a substantially higher estimated prevalence of undernutrition than global average estimates. In multivariable meta-regression, a combination of human development index and United Nations region (a proxy for geographical variation) explained 54%, 56%, and 66% of the variation in stunting, wasting, and underweight prevalence, respectively. Our findings demonstrate that regional, subregional, and country disparities in undernutrition remain, and the residual gaps to close towards achieving the second sustainable development goal-ending undernutrition by 2030.

Obesity and eating behavior from the perspective of twin and genetic research

Obesity has dramatically increased during the last decades and is currently one of the most serious global health problems. We present a hypothesis that obesity is a neuro-behavioral disease having a strong genetic background mediated largely by eating behavior and is sensitive to the macro-environment; we study this hypothesis from the perspective of genetic research. Genetic family and genome-wide-association studies have shown well that body mass index (BMI, kg/m²) is a highly heritable and polygenic trait. New genetic variation of BMI emerges after early childhood. Candidate genes of BMI notably express in brain tissue, supporting that this new variation is related to behavior. Obesogenic environments at both childhood family and societal levels reinforce the genetic susceptibility to obesity. Genetic factors have a clear influence on macro-nutrient intake and appetite-related eating behavior traits. Results on the gene-by-diet interactions in obesity are mixed, but emerging evidence suggests that eating behavior traits partly mediate the effect of genes on BMI. However, more rigorous prospective study designs controlling for measurement bias are still needed.

No Evidence for Passive Gene-Environment Correlation or the Influence of Genetic Risk for Psychiatric Disorders on Adult Body Composition via the Adoption Design

The relationship between genetic and environmental risk is complex and for many traits, estimates of genetic effects may be inflated by passive gene-environment correlation. This arises because biological offspring inherit both their genotypes and rearing environment from their parents. We tested for passive gene-environment correlation in adult body composition traits using the 'natural experiment' of childhood adoption, which removes passive gene-environment correlation within families. Specifically, we compared 6165 adoptees with propensity score matched non-adoptees in the UK Biobank. We also tested whether passive gene-environment correlation inflates the association between psychiatric genetic risk and body composition. We found no evidence for inflation of heritability or polygenic scores in non-adoptees compared to adoptees for a range of body composition traits. Furthermore, polygenic risk scores for anorexia nervosa, attention-deficit/hyperactivity disorder and schizophrenia did not differ in their influence on body composition traits in adoptees and non-adoptees. These findings suggest that passive gene-environment correlation does not inflate genetic effects for body composition, or the influence of psychiatric disorder genetic risk on body composition. Our design does not look at passive gene-environment correlation in childhood, and does not test for 'pure' environmental effects or the effects of active and evocative gene-environment correlations, where child genetics directly influences home environment. However, these findings suggest that genetic influences identified for body composition in this adult sample are direct, and not confounded by the family environment provided by biological relatives.

Methylation of Hypothalamic Tsc1-mTOR Signaling in Regulation of Obesity and Obesity Resistance

The Tsc1-mTOR signaling pathway is often related to obesity, and epigenetic modification may lead to expression changes of obesity-related gene. Therefore, we aim to investigate the methylation of the Tsc1-mTOR signaling pathway in regulation of obesity susceptibility. Wistar rats were fed a normal diet or a high-fat diet to develop animal models. Protein and mRNA expression levels of Tsc1-mTOR signaling in the hypothalamus were determined by Western blot and quantitative real-time PCR. Methylation of Tsc1 gene promoter was detected by bisulfite genomic sequence. Both mRNA and protein expression levels of Tsc1 in DIO group hypothalamus were lower; mTOR and its downstream targets S6K1, 4EBP1, and S6 protein expression levels were higher than those of the DIO-R group and the chow group. The Tsc1 gene promoter methylation rate in the hypothalamus was 92.05 ± 3.07% in the DIO group, 87.27 ± 1.91% in the DIO-R group, and 88.18% ± 3.20% in the chow group, respectively, with significantly higher levels in the DIO group. Both the expression levels of Tsc1 gene promoter methylation and Tsc1-mTOR signaling pathway in the hypothalamus of DIO rats and DIO-R rats are different. These findings may shed light on the potential mechanism for the differentiation of obesity susceptibility.

One size does not fit all. How universal standards for normal height can hide deprivation and create false paradoxes

Public health practitioners and social scientists frequently compare height against one-size-fits-all standards of human growth to assess well-being, deprivation, and disease risk. However, underlying differences in height can make some naturally tall populations appear well-off by universal standards, even though they live in severe states of deprivation. In this article, I describe the worldwide extent of these population differences in height and illustrate how using a universal yardstick to compare population height can create puzzling disparities (eg, between South Asia and sub-Saharan Africa) while also underestimating childhood stunting in specific world regions (eg, West Africa and Haiti). I conclude by discussing potential challenges of developing and implementing population-sensitive standards for assessing healthy development.

Can shorter mothers have taller children? Nutritional mobility, health equity and the intergenerational transmission of relative height

This study develops the concept of nutritional mobility, defined here as the probability that a mother ranked low in her cohort's height distribution will have a child who attains a higher rank order. We demonstrate that rank-order regression provides a robust metric of health equity, revealing differences in opportunities for each child to reach their own growth potential. We estimate four indicators of nutritional mobility and test for associations between nutritional mobility and various local economic and environmental factors. Nutritional mobility has improved over time, and the nutrition environment contributes about 2.86 times as much as a mother's height to her child's expected rank in height-for-age. Populations with the least mobility are in Latin America, and the most mobility is in more urbanized areas of Africa and Asia. Rank-order mobility is an important aspect of health equity, offering valuable insight into the role of socioecological factors in nutrition improvement across generations.