'Genes are not destiny' when it comes to weight

October 9, 2018, University College London
Credit: Pixabay 

A healthy home environment could help offset children's genetic susceptibilities to obesity, according to new research led by UCL.

The study, published this week in JAMA Pediatrics, found that the impact of genetic factors on is roughly halved if a child is bought up in a less 'obesogenic' where healthy eating and exercise is more prevalent.

Researchers collected data on Body Mass Index (BMI) and home environments from 925 twin pairs in the British Gemini cohort. The twins' families were asked in detail about many aspects of their home diet, physical activity, and media environments, such as the amount of healthy food in the home, how about how many media devices there were in the home and family media viewing habits.

This information was used to create a score for each home that indicated if it was a 'high-risk' or 'low-risk' environment for obesity. Of the 925 twin pairs, 508 were living in healthier, 'low-risk' home environments and 417 were living in less healthy 'high-risk' home environments.

"Our study is the first to examine how the early home environment relates to a child's genetic susceptibility to being overweight, even though it is widely believed to be a key influence on weight," said first author Dr. Stephanie Schrempft (UCL Behavioural Science and Health).

"The finding that on weight was stronger among children living in riskier home environments supports a theory, developed by our group, that genetic susceptibility to obesity will be most highly expressed when individuals are living in a obesogenic environment that encourages excess consumption and low physical activity. In other words, 'the genetic background loads the gun, but the environment pulls the trigger'."

The researchers used the twin design to estimate the genetic and environmental influence on the BMI of children in both high- and low-risk obesogenic home environments. A third of the group consisted of who are 100% genetically the same, and two-thirds of fraternal twins who are approximately 50% genetically the same. Comparing the two types of twins allowed researchers to estimate genetic and environmental influence on BMI.

If identical twins are much more similar than fraternal twins for BMI, genes are important in shaping it. If the two types of twins are fairly similar for BMI despite their genetic differences, the home environment is an important factor.

Researchers found a much larger difference in similarity between identical and when children were bought-up in a high-risk home environment, indicating a greater genetic influence on children's BMI in an obesogenic environment. In contrast, in a low-risk home environment, both types of twins were much more similar, highlighting that a healthy home environment can override genetic influence on BMI.

In the high risk environment, genetic differences between children explained 86% of differences in children's BMI. In the low risk environment, between children were less important in explaining differences in their BMI, accounting for only 39% of BMI differences.

Dr. Clare Llewellyn (UCL Behavioural Science and Health) senior author, said: "We have known for decades that genes help to explain why people differ in their weight, but this often leads to the misconception that weight can't be changed. This study shows that genes are not destiny when it comes to weight. In childhood, the home family environment seems to influence the extent to which genetic predisposition to a lower or higher weight is fully expressed."

In particular, for children growing up in a healthy home food environment, genetic influence on weight was fairly modest, and the was just as important. Ironically, this study points more than anything to the importance of the early environment for shaping a child's weight."

Explore further: Editorial praises childhood obesity study that finds 'genes are not destiny'

More information: Stephanie Schrempft et al. Variation in the Heritability of Child Body Mass Index by Obesogenic Home Environment, JAMA Pediatrics (2018). DOI: 10.1001/jamapediatrics.2018.1508

Related Stories

Editorial praises childhood obesity study that finds 'genes are not destiny'

October 2, 2018
University at Buffalo childhood obesity experts are praising a study published Monday in JAMA Pediatrics that rigorously assessed how the home environments of young children who are genetically at high risk for obesity can ...

How nature, nurture shape the sleeping brain

September 24, 2018
Some patterns of electrical activity generated by the brain during sleep are inherited, according to a study of teenage twins published in JNeurosci. Pinpointing the relative contributions of biology and experience to sleep ...

Genes shown to influence how well children do throughout their time at school

September 4, 2018
Children differ widely in how well they do at school. In recent years, researchers have shown that around two-thirds of differences in school achievement can be explained by differences in children's genes.

Emotional eating in childhood is learned at home

June 19, 2018
The tendency for children to eat more or less when stressed and upset is mainly influenced by the home environment and not by genes, according to a new UCL-led study.

Twin study highlights importance of both genetics and environment on gene activity

August 3, 2018
New research highlights the extent to which epigenetic variation is influenced by both inherited and environmental factors.

Looking past peer influence: Genetic contributions to increases in teen substance use?

April 25, 2018
Parents and adults spend a lot of time worrying about the influence of friends and peers when it comes to teen substance use - drinking alcohol, binge drinking, marijuana use and other illicit drugs. Is it all about an adolescent's ...

Recommended for you

Teens get more sleep with later school start time, researchers find

December 12, 2018
When Seattle Public Schools announced that it would reorganize school start times across the district for the fall of 2016, the massive undertaking took more than a year to deploy. Elementary schools started earlier, while ...

Large restaurant portions a global problem, study finds

December 12, 2018
A new multi-country study finds that large, high-calorie portion sizes in fast food and full service restaurants is not a problem unique to the United States. An international team of researchers found that 94 percent of ...

Study highlights potential benefits of continuous EEG monitoring for infant patients

December 12, 2018
A recent retrospective study evaluating continuous electroencephalography (cEEG) of children in intensive care units (ICUs) found a higher than anticipated number of seizures. The work also identified several conditions closely ...

Scientists have identified and modelled a distinct biology for paediatric AML

December 11, 2018
Scientists have identified and modelled a distinct biology for paediatric acute myeloid leukaemia, one of the major causes of death in children.

BMI is a good measure of health after all, new study finds

December 11, 2018
A new study from the University of Bristol supports body mass index (BMI) as a useful tool for assessing obesity and health.

A correlation between obesity and income has only developed in the past 30 years

December 11, 2018
It is well known that poorer Americans are more likely to be obese or suffer from diabetes; there is a strong negative correlation between household income and both obesity and diabetes. This negative correlation, however, ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

pntaylor
not rated yet Oct 09, 2018
"Genes are not destiny' when it comes to weight"

And, once again, we have a No Sht study.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.