If you grew up in the 80s and 90s and struggled with picky eating, chances are you have some painful memories of mealtime battles and stressed-out parents. Thankfully, knowledge and understanding of these issues has moved on somewhat, but there’s still stigma attached to the label of “fussy” or “picky” – both for kids and their parents. A new study might help us shed some of that, by finding that almost all food fussiness in kids is driven by genetics.

The researchers focused on families with sets of identical or non-identical twins. All participants were part of a major cohort study of twins born in England and Wales in 2007. Data collected when the children were aged 16 months, 3 years, 5 years, 7 years, and 13 years was used. This included the Child Eating Behavior Questionnaire, a well-established way of measuring both “food fussiness” and a fear of trying new foods, which was completed by the parents.

Comparing identical and non-identical twins is useful when scientists are trying to pin down the influence of genetics on a particular trait. Pairs of twins are the same age and are likely to experience very similar upbringings; however, identical twins share a large proportion of genetic similarity, while non-identical twins do not (they’re related in the same way as other siblings). 

In this study, the team found that non-identical twins were much less similar in their fussy eating than identical twins, suggesting that their genetics play a bigger role than their environments. They concluded that at 16 months, genetics accounts for about 60 percent of differences in food fussiness; this rose to at least 74 percent between the ages of 3 and 13.

As the children got older, and presumably also spent more time out of the home without their sibling around and with their own friendship groups, unique environmental factors began to play a more important role – around 25 percent between ages 7 and 13. 

Shared environmental influences, on the other hand, were found to be significant only in very young kids.

“Shared environmental factors, such as sitting down together as a family to eat meals, may only be significant in toddlerhood,” said senior author Dr Clare Llewellyn in a statement. “This suggests that interventions to help children eat a wider range of foods, such as repeatedly exposing children to the same foods regularly and offering a variety of fruits and vegetables, may be most effective in the very early years.”

But the main message is that, while parents often feel huge amounts of anxiety around their kids’ eating habits and face judgment from other parents, the majority of fussy eating in kids is innate. 

“This behaviour is not a result of parenting,” said lead author Dr Zeynep Nas. “Our study also shows that fussy eating is not necessarily just a ‘phase’, but may follow a persistent trajectory.”

If you’re currently in the throes of toddler parenting, struggling to understand why your child is suddenly refusing foods they loved two weeks ago, it might help to know that while pickiness can definitely persist beyond childhood, that doesn’t mean it’s fixed for life. 

“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,” said senior author Dr Alison Fildes.

The study was limited by smaller sample sizes at some timepoints, as well as a bias towards families of above-average socioeconomic circumstances. The team also highlighted that future research should extend beyond the West to look at different cultural practices and regions with different levels of food security.

Picky eating is very common, and most medical advice suggests that a calm approach is best. Old-fashioned thinking about forcing kids to clean their plates is out of the window – we know better now. Instead, being patient with kids, removing some of the focus on food, not comparing them to their peers, and trying out different ways of cooking and serving foods is likely to lead to much better outcomes.

The study is published in The Journal of Child Psychology and Psychiatry.