It turns out that picky eaters may not be making a conscious choice after all: Their genes significantly influence their food preferences, according to a recent study published in the Journal of Child Psychology and Psychiatry. The research suggests that genetic factors play a much larger role in determining what foods people like or dislike than previously thought, meaning some individuals may be hardwired to be more selective about what they eat. Food fussiness, the term that will be used for this article, is the tendency to eat a small range of foods due to textures or taste preferences or reluctance to try new foods.
The study, which was funded by the UK mental health charity MQ Mental Health Research, compared survey results from parents with identical and nonidentical twins in England and Wales from 16 months to 13 years. Researchers from University College London (UCL), King’s College London, and the University of Leeds noted that the average levels of food fussiness were relatively stable during this time frame, reaching maximum levels of pickiness around age seven and declining after that. The team concluded that genetic differences in the population resulted in a 60% variation in food fussiness at 16 months, increasing to more than 74% between the ages of 3 and 13.
Of course, genetics are not the only factor at play when discussing human habits. Environmental factors that the twins shared, such as types of food eaten at home, were found to be most significant in toddlerhood. Environmental factors that were individual to each twin, such as personal experiences, became more influential during later years.
Lead author Dr. Zeynep Nas, from UCL Behavioural Science & Health, said, “Food fussiness is common among children and can be a major source of anxiety for parents and caregivers, who often blame themselves for this behaviour [sic] or are blamed by others. We hope our finding that fussy eating is largely innate may help to alleviate parental blame. This behaviour is not a result of parenting”.
Senior author Professor Clare Llewellyn noted that genetic factors are the predominant influence for food fussiness, but there is some environmental role. She noted that since environmental factors seemed to only be prevalent in toddlerhood, it is likely that interventions to help children eat a wider variety of foods would be most effective in the very early years as compared to later.
Following their own study, the researchers analyzed data from the Gemina study, a UCL-led study on the largest twin cohort ever created to study the genetic and environmental contributions to early growth and development. This study involved 2,400 sets of twins, where parents filled out question-based surveys about their children’s eating habits at 16 months, three, five, seven, and thirteen years of age.
To determine the differences between genetics and environmental influences, researchers compared the fussy eating habits of non-identical twin pairs. Non-identical twins only share 50% of their genes, whereas identical twins share 100%. They found that non-identical twins had less similarities in their pickiness as compared to identical twins, demonstrating a large genetic influence in food fussiness.
Overall, unique environmental factors accounted for a quarter of individual differences between children between ages seven and thirteen, whereas shared environmental factors made up a quarter of individual differences in children at 16 months but then were negligible in later years.
Senior author Dr Alison Fildes from the University of Leeds noted that “Although fussy eating has a strong genetic component and can extend beyond early childhood, this doesn’t mean it is fixed. Parents can continue to support their children to eat a wide variety of foods throughout childhood and into adolescence, but peers and friends might become a more important influence on children’s diets as they reach their teens.”
Researchers determined that there were some limitations to their studies findings, stating that there were different numbers of participants at different time points and that the study’s sample had a large caucasian population from British households of higher socioeconomic status.
In the future, their research will focus on non-western populations where food culture, parental feeding practices, and food security may be vastly different.
