Genetic and Environmental Factors Influencing BMI Development from Adolescence to Young Adulthood

Abstract

BMI increases progressively from adolescence to young adulthood. The aims of the present study were firstly, to investigate the extent to which genetic and environmental influences account for differences in BMI trajectories during this period, and secondly to examine whether boys and girls show divergences in these influences, as their BMI normally start differing across adolescence. The study sample consisted of 4,915 monozygotic and like- and unlike-sex dizygotic twins, born between 1975 and 1979. Data on BMI was gathered when twins were on average 16.1, 17.1, 18.6 and 24.4 years old. Genetic and environmental influences on the BMI trajectories were modeled using a latent growth curve approach. The results showed that the heritability of BMI decreased slightly after the adolescence period, from ≈ 80 to 70%. BMI transition from adolescence to young adulthood was best described by a quadratic trajectory that was highly accounted (61.7-86.5%) for by additive genetic influences. Genetic influences on BMI level showed a low correlation with those on the trend in BMI with age indicating that different sets of genes underlie the change of BMI during this period. Importantly, the analyses also evidenced that different genetic and environmental influences may underlie boys and girls evolution. In conclusion, our results suggested specific genetic influences accounting for the BMI rate-of-change from adolescence to young adulthood. This indicates that the specific genes behind BMI level may not be the same as the genes affecting BMI change which should be taken into account in further efforts to identify these genes.

Estimating Modifying Effect of Age on Genetic and Environmental Variance Components in Twin Models

“…Nevertheless, one of the major issues posing potential challenge is that many twin data sets contain individuals across a wide range of age and the variances of genetic and environmental components for many complex traits such as body mass index (BMI) and height change over age (Lajunen et al 2009;Elks et al 2012) or birth cohorts (Silventoinen et al 2000). For example, the variances of genetic and environmental components and thus the heritability of BMI have been found to diverge with age in a Finnish study of adolescent twins (Lajunen et al 2009) and another of adolescents and young adults (Ortega-Alonso et al 2012), implying that potential gene-environment (G 3 E) interactions play a notable role in these complex traits. During childhood when a twin pair is raised in a similar environment, the common environmental effects may be present in early childhood when children are dependent on their parents and then drop after midchildhood when they start to get more independence (Silventoinen et al 2009).…”

“…For example, the variances of genetic and environmental components and thus the heritability of BMI have been found to diverge with age in a Finnish study of adolescent twins (Lajunen et al 2009) and another of adolescents and young adults (Ortega-Alonso et al 2012), implying that potential gene-environment (G 3 E) interactions play a notable role in these complex traits. During childhood when a twin pair is raised in a similar environment, the common environmental effects may be present in early childhood when children are dependent on their parents and then drop after midchildhood when they start to get more independence (Silventoinen et al 2009).…”

Assessing the genetic correlations between early growth parameters and bone mineral density: A polygenic risk score analysis

“…BMI increases progressively from adolescence to young adulthood. It has been found that adolescent BMI is highly heritable (70–90%) [14]. The BMI transition from adolescence to young adulthood was best described by a quadratic trajectory that was highly accounted (61.7–86.5%) by additive genetic influences [14].…”

“…It has been found that adolescent BMI is highly heritable (70–90%) [14]. The BMI transition from adolescence to young adulthood was best described by a quadratic trajectory that was highly accounted (61.7–86.5%) by additive genetic influences [14]. Additionally, twin studies have shown that breast size is about 56% heritable [15].…”

Age at dieting onset, body mass index, and dieting practices. A twin study

“…15 In addition, other familial factors, such as learned eating habits, likely also contribute to an individual’s weight. Dietary behaviors learned as a child generally continue on into adulthood.…”