Nature and nurture in fussy eating from toddlerhood to early adolescence: findings from the Gemini twin cohort

Abstract

BackgroundFood fussiness (FF) describes the tendency to eat a small range of foods, due to pickiness and/or reluctance to try new foods. A common behaviour during childhood, and a considerable cause of caregiver concern; its causes are poorly understood. This is the first twin study of genetic and environmental contributions to the developmental trajectory of FF from toddlerhood to early adolescence, and stability and change over time.MethodsParticipants were from Gemini, a population-based British cohort of n=4804 twins born in 2007. Parents reported on FF using the Child Eating Behaviour Questionnaire ‘food fussiness’ scale when children were 16 months (n=3854), and 3 (n=2666), 5 (n=2098), 7 (n=703) and 13 years old (n=970). A mixed linear model examined the trajectory of FF, and a correlated factors twin model quantified genetic and environmental contributions to variation in and covariation between trajectory parameters. A longitudinal Cholesky twin model examined genetic and environmental influences on FF at each discrete age.ResultsA single FF trajectory was identified for all children, characterised by increases from 16 months to 7 years, followed by a slight decline from 7-13 years. All trajectory parameters were under strong genetic influence (>70%) that was largely shared, indicated by high genetic correlations. Discrete age analyses showed that genetic influence on FF increased significantly after toddlerhood (16 months: 60%, 95%Cl:53%-67%; 3 years: 83%; 81%-86%), with continuing genetic influence as indicated by significant genetic overlap across every age. Shared environmental influences were only significant during toddlerhood. Unique environmental influences explained 15-26% of the variance over time, with some enduring influence from 5 years onwards. ConclusionsIndividual differences in FF were largely explained by genetic factors at all ages. Early life interventions for fussy eating may be most effective during toddlerhood when malleable environmental factors play a sizeable role.