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

Sarah Warkentin,Milton Severo,Andreia Oliveira,Alison Fildes

doi:10.1007/s40519-021-01322-1

Abstract

PurposeGiven 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.MethodsParticipants 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.ResultsModerate 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).ConclusionThere 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 evidenceEvidence obtained from well-designed cohort or case–control analytic studies.

Highlights

Genetic and environmental factors interact in many complex ways in the development of childhood obesity [1]
Given the great individual variability in adiposity, and the increasing exposure to modern day obesogenic food environments over time, it is believed that individuals respond in divergent ways to the environment that they live in, i.e., genetic predispositions to being overweight seem to be enhanced in higher risk home environments in preschoolers [2] and tend to increase from early childhood to school-age years [3] until late adolescence [4], reflecting the greater external exposure to obesogenic food environments [5], which can be defined as a genotype–environment interaction [6]
A significantly higher Intra-class correlations (ICCs) was observed among DZ twins (ICC: 0.76; 95% confidence intervals (CI) 0.62; 0.85), suggesting that this trait has strong environmental factors explaining its variability

Summary

Introduction

Genetic and environmental factors interact in many complex ways in the development of childhood obesity [1]. Given the great individual variability in adiposity, and the increasing exposure to modern day obesogenic food environments over time, it is believed that individuals respond in divergent ways to the (food) environment that they live in, i.e., genetic predispositions to being overweight seem to be enhanced in higher risk home environments in preschoolers [2] and tend to increase from early childhood to school-age years [3] until late adolescence [4], reflecting the greater external exposure to obesogenic food environments [5], which can be defined as a genotype–environment interaction [6]. A strong influence of common environmental factors was observed in middle-childhood and disappeared after 15 years of age [8]

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