A longitudinal study of British children found that fussy eating is largely determined by genetic factors at all ages. However, it also shows an environmental influence during toddlerhood, suggesting that early interventions to prevent it might achieve some success. The paper was published in the Journal of Child Psychology and Psychiatry.
Fussy eating, also known as picky eating or food fussiness, is the tendency to eat only a limited range of foods. Individuals with this trait are particular about the flavor or texture of food and are reluctant to try new foods and flavors. While picky eating is commonly observed in young children, it can persist into adulthood. It typically arises in environments where food variety is encouraged, such as at school, social gatherings, or even at home when someone else prepares the food.
Because fussy eaters limit the range of foods they consume, they may experience nutritional deficiencies. When fussy eaters are children, their caregivers often face stress and frustration trying to manage their eating habits. Research suggests that early exposure to a variety of foods and positive mealtime experiences can help reduce food fussiness.
Study author Zeynep Nas and her colleagues aimed to explore the developmental trajectory of fussy eating from toddlerhood to early adolescence and estimate the contribution of genetic and environmental factors to individual differences in this trait.
Participants in the study were drawn from Gemini, a population-based cohort of twin children born in England and Wales in 2007. These children have been followed as part of an ongoing research project for over a decade. At the study’s onset, the children were 16 months old, and there were 3,854 participants. By the time they reached 13 years of age, 970 participants remained in the study.
The researchers analyzed data on fussy eating collected at different time points using the parent-reported Child Eating Behavior Questionnaire, completed when participants were 3, 5, 7, and 13 years old. They also examined data on whether the children were monozygotic or dizygotic twins, as well as their age and sex.
The results showed that children whose food fussiness was above average at the earliest age tended to become even pickier as they grew older. Children who displayed a stronger increase in food fussiness over time also tended to show steeper decreases in food fussiness between the ages of 7 and 13, although their levels of food fussiness remained above average.
The correlation of food fussiness scores among monozygotic twins (who are genetically identical) was twice as high as that among dizygotic twins, indicating that food fussiness is largely genetically driven. Over the years, food fussiness remained moderately to highly stable throughout childhood and early adolescence.
The total contribution of genetic influences to individual differences in food fussiness ranged from 60% to 84%. The heritability of food fussiness was lower at 16 months than at any other time point analyzed in the study. At the same time, shared environmental factors accounted for 25% of individual differences in food fussiness at 16 months but became negligible and indistinguishable from random variation at later ages.
“This novel longitudinal examination provides evidence of FF [food fussiness] being a highly heritable trait that is relatively stable from toddlerhood into early adolescence, with genetic influences largely responsible for its continuity,” the study authors concluded.
“Parents are not to blame for their children’s innate fussy eating behaviors. Interventions targeting FF could start as early as toddlerhood and may need to be tailored and intensive at different developmental time points.”
The study sheds light on the nature of picky eating. However, the assessments of picky eating were based on parental reports, and parents were aware when their children were monozygotic twins. This awareness might have led parents to evaluate their monozygotic twin children as more similar than they truly were, potentially inflating the observed similarities in food fussiness scores and affecting the study’s results and conclusions. Additionally, as the study progressed, a large proportion of participants dropped out, which may have influenced the findings.
The paper, “Nature and nurture in fussy eating from toddlerhood to early adolescence: findings from the Gemini twin cohort,” was authored by Zeynep Nas, Moritz Herle, Alice R. Kininmonth, Andrea D. Smith, Rachel Bryant-Waugh, Alison Fildes, and Clare H. Llewellyn.