Overeating by children who are stressed or upset is mainly influenced by their home environment and not by their genes, according to new research led by UCL.

The researchers found that genetics play a surprisingly small role in young children's emotional overeating, unlike other eating behaviours seen in early childhood, such as food fussiness. Their study 'Home environment shapes emotional eating' is published today in the journal Child Development.

Previous research had focussed on how adults use food to cope with stress, sadness and other negative emotions. However, little was known about the development of emotional overeating in childhood and this study is the first to examine the roles of genetic and environmental factors.

The researchers collected data from over 4,800 British twins born in 2007 and taking part in the Gemini twin study.

Parents described their twins' tendencies to eat more than usual when experiencing emotions, such as feeling upset or anxious. They answered questions on two occasions; when their twins were 16 months old, and again when they were 5 years old. The researchers compared how similar identical and non-identical twin pairs were for emotional eating.

"We showed that children's emotional overeating is mostly influenced by environmental factors completely shared by twin pairs. Future research should look towards home environmental factors that might play a role, such as certain parental feeding practices or stress around the dinner table. Genes are largely unimportant for emotional overeating in childhood," said Moritz Herle, (UCL Behavioural Science and Health), who co-led the research.

"The results were surprising because previous studies have shown that other eating behaviours are strongly influenced by genes in early childhood; such as being fussy about food. Findings also contrasted with studies of adults that have shown that the tendency to eat emotionally is partly shaped by genes, while the home family environment we grew up in plays no role at all when we're older."

The researchers found that genes contributed just 10% and 4% to the trait of emotional overeating, at the ages of 16 months and five years respectively.

"People who have a tendency to eat for comfort when they are stressed or upset have been found to be more likely to gain weight and develop other mental health problems, such as binge eating disorder. Understanding when and how these tendencies develop is useful, because it helps researchers to give advice about how to prevent or change it," said Dr Clare Llewellyn, (UCL Behavioural Science and Health), senior lead researcher for the paper.

"The findings from this study suggest that if we want to stop children becoming emotional eaters, we should focus on influences within the family. Using food as a reward or to sooth a child who is upset might be one of the ways that children learn to overeat in response to negative emotions."

Article: The home environment shapes emotional eating, Herle M, Fildes A, Rijsdijk F, Steinsbekk S and Llewellyn CH, Child Development, published 25 April 2017.