A person's partner has a greater impact on their chances of becoming obese than their upbringing, findings of a new study show.
Researchers at the University of Edinburgh have analyzed data provided by 20,000 Scottish families.
They found that by middle age, the routine a couple shares—including their diet and exercise habits—has a greater impact than the lifestyle they shared with their siblings and parents when growing up.
Professor Chris Haley of the Medical Research Council's Human Genetics Unit led the research and said that the study will help scientists better understand the links between obesity, genetics, and lifestyle.
He added that the study findings support the message that lifestyle changes in adulthood may mean that people from families with a history of obesity can still reduce their risk by changing their habits.
"Although genetics accounts for a significant proportion of the variation between people, our study has shown the environment you share with your partner in adulthood also influences whether you become obese and this is more important than your upbringing," said Professor Haley.
The information was gathered as part of the Generation Scotland project, a resource of health data that helps researchers to investigate genetic links to health conditions.
Scientists compared people's genetics and home environments in childhood and adulthood and related those to measures linked to health and obesity.
A total of 16 measures were considered including waist to hip ratio, blood pressure, body fat content, and body mass index.
The study is published in the journal PLoS Genetics.