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

Lise Dubois,Finn Rasmussen,Margaret J Wright,Axel Skytthe,Daniel Pérusse,Paul Lichtenstein,Fabiola Tatone-Tokuda,Manon Girard,Jacob Hjelmborg,Kirsten Ohm Kyvik,Nicholas G Martin

doi:10.1371/journal.pone.0030153

Abstract

ObjectiveTo examine the genetic and environmental influences on variances in weight, height, and BMI, from birth through 19 years of age, in boys and girls from three continents.Design and SettingsCross-sectional twin study. Data obtained from a total of 23 twin birth-cohorts from four countries: Canada, Sweden, Denmark, and Australia. Participants were Monozygotic (MZ) and dizygotic (DZ) (same- and opposite-sex) twin pairs with data available for both height and weight at a given age, from birth through 19 years of age. Approximately 24,036 children were included in the analyses.ResultsHeritability for body weight, height, and BMI was low at birth (between 6.4 and 8.7% for boys, and between 4.8 and 7.9% for girls) but increased over time, accounting for close to half or more of the variance in body weight and BMI after 5 months of age in both sexes. Common environmental influences on all body measures were high at birth (between 74.1–85.9% in all measures for boys, and between 74.2 and 87.3% in all measures for girls) and markedly reduced over time. For body height, the effect of the common environment remained significant for a longer period during early childhood (up through 12 years of age). Sex-limitation of genetic and shared environmental effects was observed.ConclusionGenetics appear to play an increasingly important role in explaining the variation in weight, height, and BMI from early childhood to late adolescence, particularly in boys. Common environmental factors exert their strongest and most independent influence specifically in pre-adolescent years and more significantly in girls. These findings emphasize the need to target family and social environmental interventions in early childhood years, especially for females. As gene-environment correlation and interaction is likely, it is also necessary to identify the genetic variants that may predispose individuals to obesity.

Highlights

The global obesity epidemic is accelerating [1] and has affected virtually all ages, races, and sexes in developed and developing countries [2,3]
Adoption studies provide strong evidence for large genetic influences on variations in body mass index (BMI), with heritability estimates ranging from 50% to over 90%, leaving the remaining variance attributed to environmental influences, whether common to family members/siblings or unique to the individual [8,9,10]
Population-based data obtained from large twin birth-cohorts in three different continents, the present study aims to describe the distribution of weight, height, and BMI in MZ and DZ same- and opposite-sex twin pairs, from birth through 19 years of age, and examine the genetic and environmental influences on variances in these body measures over each year of age during the first 19 years of life; sexlimitation of genetic and environmental effects will be explored at each age examined

Summary

Introduction

The global obesity epidemic is accelerating [1] and has affected virtually all ages, races, and sexes in developed and developing countries [2,3]. Adoption studies provide strong evidence for large genetic influences on variations in body mass index (BMI), with heritability estimates ranging from 50% to over 90%, leaving the remaining variance attributed to environmental influences, whether common to family members/siblings or unique to the individual [8,9,10]. These estimates have varied widely across studies due to differences in study types, populations, and ages targeted

Methods

Results

Discussion

Conclusion