Genetic and environmental influences on eating behaviors in 2.5- and 9-year-old children: a longitudinal twin study
1 Institute of Population Health, University of Ottawa, 1 Stewart St., Ottawa, ON, Canada
2 Department of Epidemiology & Community Medicine, University of Ottawa, 451 Smyth Rd, Ottawa, ON, Canada
3 Hjelt Institute, Department of Public Health, University of Helsinki, P.O. Box 41, Mannerheimintie 172, Helsinki, Finland
4 National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, Mannerheimintie 166, Helsinki, Finland
5 Institute for Molecular Medicine (FIMM), University of Helsinki, P.O. Box 20, Tukholmankatu 8, Helsinki, Finland
6 Nutrition Sciences Program, University of Ottawa, 25 University Private, Ottawa, ON, Canada
7 Research Unit on Children’s Psychosocial Maladjustment (GRIP), Université de Montréal, 3050 Édouard-Montpetit St., Montréal, QC, Canada
8 School of Public Health, Physiotherapy & Population Science, University College Dublin, Dublin, Ireland
9 École de psychologie, Université Laval, 2325 rue des Bibliothèques, Québec, QC, Canada
10 Département d’anthropologie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, QC, Canada
International Journal of Behavioral Nutrition and Physical Activity 2013, 10:134 doi:10.1186/1479-5868-10-134Published: 7 December 2013
Eating behaviors during childhood are related both to children’s diet quality and to their weight status. A better understanding of the determinants of eating behavior during childhood is essential for carrying out effective dietary interventions.
We assessed the contribution of genetic and environmental factors to variations in selected eating behaviors in early and late childhood. Information on eating behaviors came from questionnaires administered to parents of children participating in the Quebec Newborn Twin Study when the twins were 2.5 and 9 years old (n = 692 children). Dichotomous variables were derived and analyzed using structural equation modeling, as part of a classic twin study design. We performed univariate and bivariate longitudinal analyses to quantify sources of variation and covariation across ages, for several eating behavior traits.
We found moderate to strong heritability for traits related to appetite such as eating too much, not eating enough and eating too fast. Univariate analysis estimates varied from 0.71 (95% CI: 0.49, 0.87) to 0.89 (0.75, 0.96) in younger children and from 0.44 (0.18, 0.66) to 0.56 (0.28, 0.78) in older children. Bivariate longitudinal analyses indicated modest to moderate genetic correlations across ages (rA varying from 0.34 to 0.58). Common genetic influences explained 17% to 43% of the phenotypic correlation between 2.5 and 9 years for these appetite-related behaviors. In 9-year-old children, food acceptance traits, such as refusing to eat and being fussy about food, had high heritability estimates, 0.84 (0.63, 0.94) and 0.85 (0.59, 0.96) respectively, while in younger children, the shared environment (i.e., common to both twins) contributed most to phenotypic variance. Variances in meal-pattern-related behaviors were mostly explained by shared environmental influences.
Genetic predispositions explain a large part of the variations in traits related to appetite during childhood, though our results suggest that as children get older, appetite-related behaviors become more sensitive to environmental influences outside the home. Still, for several traits environmental influences shared by twins appear to have the largest relative importance. This finding supports the notion that familial context has considerable potential to influence the development of healthy eating habits throughout childhood.