Obesity appears influenced more by choices made by a person and his or her partner, rather than a person’s family experience or upbringing.
By middle age, choices made by couples — including those linked to diet and exercise — have a much greater impact than the lifestyle each shared with siblings and parents growing up, say researchers.
Although by middle age siblings have a shared risk of being obese, investigators believe this is mostly attributable to their shared genetic inheritance rather than any habits instilled during their shared upbringing.
University of Edinburgh researchers believe the study will help scientists better understand links between obesity, genetics, and lifestyle habits.
Investigators say the study reinforces the message that lifestyle changes in adulthood can have a significant impact in tackling obesity, regardless of a person’s genetic profile.
For the study, investigators analyzed data provided by 20,000 people from Scottish families. They compared people’s family genetics and home environments in childhood and adulthood as related to adult 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 information was originally gathered as part of the Generation Scotland project — a national resource of health data that helps researchers to investigate genetic links to health conditions.
The study appears in the journal PLOS Genetics.
Professor Chris Haley of the Medical Research Council’s Human Genetics Unit at the University of Edinburgh led the study.
“Although genetics accounts for a significant proportion of the variation between people, our study has shown that the environment you share with your partner in adulthood also influences whether you become obese and this is more important than your upbringing,” Haley said.
“The findings also show that even people who come from families with a history of obesity can reduce their risk by changing their lifestyle habits.”