Parents who find themselves annoyed by their child’s picky eating habits take heart: the refusal to tuck into a wider range of foods is largely due to genes rather than parenting, according to scientists.
Researchers examined eating habits in toddlers to teenagers and found that, on average, fussiness about food changed little from 16 months to 13 years of age. There was a slight peak in pickiness at seven years, then a slight decline thereafter.
When they looked at the drivers of picky eating, DNA emerged as the dominant factor. Genetic variation in the population explained 60% of the differences in pickiness at 16 months, rising to 74% and more from three to 13 years of age, the study found.
The finding suggests that eating only a limited range of foods and grimacing at the prospect of trying something new is more by nature than nurture. It also suggests windows of opportunity when interventions to encourage a more varied diet may be more effective.
Dr Zeynep Nas, a behavioral geneticist at UCL, said: “The main takeaway from this work is that food cravings are not something that comes from parenting. It really comes down to the genetic differences between us.”
Other factors that influence picky eaters come from the environment they live in, the researchers said, such as sitting down to eat as a family and the types of food consumed by the people around them.
Nas and her colleagues analyzed data from the British Gemini Study, which enrolled 2,400 sets of twins to examine how genetics and the environment influence child growth. As part of the study, parents completed questionnaires about their children’s eating habits at 16 months and again at three, five, seven and 13 years of age.
To find out how much genetics contribute to picky eating habits and how much is due to environmental factors, the researchers compared the eating habits of identical and non-identical twins. While identical twins share 100% of their genes, non-identical twins share only half.
Write in the Journal of Child Psychology and Psychiatrythe researchers describe how picky eating habits are more similar among identical twins than non-identical twins, proving that genetics largely underlies differences in pickiness.
But the children’s environment also mattered. Experiences that twins shared, such as the types of food eaten at home, were important drivers of pickiness when they were toddlers. Between the ages of seven and 13, individual experiences, such as having different friends, explained about 25% of the variation in picky eating levels.
Shared experiences, such as eating as a family, were most influential in toddlers, so offering more variety around that age may be most effective, the researchers said.
Although genetics is clearly important in picky eating, this should not make parents feel disempowered, the researchers add. As Nas puts it, “Genetics is not destiny.”
Dr Alison Fildes, a co-author of the study at the University of Leeds, said: “Although picky eating has a strong genetic component and may extend beyond early childhood, this does not 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 can become a greater influence on children’s diets as they reach their teenage years.”
In 2022, Dr Nicola Pirastu at Human Technopole, an Italian research institute, has a study in the genetics of food preferences.
He found that genetics that affect taste and smell receptors are less important than variations in the brain that affect how people respond to different flavors. “Although flavor is the first driver of food choices, genetic differences are more likely to determine how the brain responds to it,” he said.
Understanding more about the genetics of food choices could help scientists identify what keeps some people from eating healthily and pave the way for modified healthy foods that are more appealing, Pirastu said. Another possibility, he added, is a new generation of drugs that shift people’s preferences toward healthier foods.
