“Picky” eaters | Which genes influence food preferences?

We all have a child around us who eats practically nothing. Is it the parents’ “fault”? Is it a genetic thing? A recent study suggests that family environment has an impact… but not as much as genes. But which genes are we talking about? Scientific explanations and nutritionist tips.

60% genetic

Many media outlets have recently reported the results of a study on picky eaters. We still know little about the causes of this reality (which overwhelms many parents!) – and this is what the researchers wanted to explore. By analyzing data from a cohort of 2,400 pairs of identical and non-identical twins, they came to this conclusion: genetic variations explain 60% of the reasons why the child is difficult at the age of 16 months, and from 74 to 84% in children aged 3 to 13. What other factors are involved? The family environment for toddlers (such as being exposed to different fruits and vegetables at home), and individual experiences for older children.

Consult the study (in English)

Complex combination

This study is not the first to focus on twins to better understand the influence of genes in our food preferences. Generally speaking, these studies conclude that around 50% of these preferences are explained by heredity. “It’s probably a complicated combination of genes and environment,” says researcher Nicola Pirastu, who works at the Human Technopole research institute in Italy. In 2022, Nicola Pirastu and colleagues published a large study in the journal Nature Communications. They surveyed the food preferences of more than 150,000 participants who provided DNA samples. Their goal: to better understand the phenomena underlying food choices.

Brain and learning

Genetically speaking, what could make a child want nothing to do with vegetables, whole grains, spicy foods, etc., while the little neighbor eats everything without complaining? It seems that everything is at stake… in the brain, and more particularly in the area of ​​the brain linked to learning. Humans rarely have an innate taste for these kinds of foods: their brain learns to like them, eventually finding a form of pleasure in them, a bit like adults who learn to like beer and coffee, explains Nicola Pirastu. “You have to be exposed to these foods, otherwise this learning cannot take place,” he summarizes. Some people apparently have more difficulty learning this specific thing. »

Supertasters

In the past, the media has talked a lot about “supertasters,” people who react strongly to the bitterness of foods. Researchers have been particularly interested in the gene that codes for the reception of bitter taste, TAS2R38, and several small studies have been published. Some have shown an association between this gene and vegetable consumption, others not. In his study covering a large sample of more than 150,000 people, Nicola Pirastu was also interested in this famous TAS2R38 gene. Result ? “We observed a strong association between this gene and alcoholic beverages, and with the addition of salt, but not with vegetables,” says Nicola Pirastu. Except with broccoli, but the association is weak. “As for the rest, the thing doesn’t hold up. »

Satisfying foods

Picky eaters often have a preference for foods that are easy to love. Like desserts, white pasta, pizza, steak… In short, for foods that are sweet or have an umami side, rich in energy, that human beings innately love. The genes associated with the perception of flavors and odors would have nothing to do with the attraction to these foods: it also happens in the brain, this time in the region responsible for the response to pleasure, explains researcher Nicola Pirastu . “People will say it’s a matter of willpower if they don’t like this type of food as much as others… but they just don’t feel the same need to eat it,” he points out. . This research therefore opens the way to new avenues for treating obesity which could make it possible, for example, to modify people’s food desires.

Small appetite

Nutritionist at the Montreal Children’s Hospital, Abigail Brodovitch thinks of another physiological factor, determining in children who refuse to eat: simply poor appetite. “Basically, there are certain children who, since birth, are really not very hungry,” she summarizes. Other factors can play a role, she says, such as reflux, constipation, hyposensitivity or hypersensitivity, autism spectrum disorder… “If we have a negative association with the activity of eating, little no matter the cause, it’s more difficult to want to continue,” summarizes Abigail Brodovitch. Vicious circles can then set in at home. “There are so many factors that come into play – genetics, biology, psychology… It’s not just the environment. And so, ultimately, it’s not the parents’ fault. »