Are problematic eating behaviors from 4- to 7-year-old explained by genetic, shared factors or individual characteristics? A longitudinal twin study.

Abstract

Studies based on twins are ideal to disentangle the relative contribution of different factors in the development of eating behaviors. This study aims to evaluate if changes in problematic eating behaviors from 4 to 7 years old are more influenced by the genetics, the shared environment of twins, or by individual characteristics of each twin. A total of 86 caregivers (mostly mothers) of twins from the Generation XXI birth cohort provided information on eating behaviors at 4 and 7 years of age. A score of problematic eating behaviors was developed. The Common fate model and the ACE model were used to estimate the effect of shared, individual, and genetic characteristics on changes in eating behaviors. At the dyadic level (shared), the eating behavior score at 4 years old was significantly and positively associated with the eating behavior at 7 years of age (β = 0.402, 95% CI 0.063;0.657). At the individual level, no significant association was observed (β = 0.020, 95% CI -0.078;0.125). The ACE model also showed the shared environment as the major responsible for the changes in eating behaviors from 4 to 7 years old. It also showed that genetic characteristics decreased their relevance overtime. This study supports that changes in eating behaviors from 4 to 7 years of age are mostly associated with the shared environment rather than individual characteristics of each twin. These results are important to improve future strategies to promote healthy environments.