The researchers, from the Centre for Economic Performance at the School of Economics and Political Science, concluded that policies to influence parents’ lifestyles could help tackle overweight in children.
For the study the researchers compiled data from 13 years of the Health Survey for England from 1997 to 2009, which measures health related behaviours in adults and children including weight and height.
The overall sample included 13,536 observations of children in which both parents were biological and 300 observations in which both parents were adoptive.
The researchers found that, when both adoptive parents were overweight, the likelihood of an adopted child being overweight was as much as 21% higher than when the parents were not overweight.
Because these children were adopted, their weight problems could be largely attributed to their parents’ lifestyles rather than to their genes, the researchers wrote.
The added that, in comparison, children with two biological overweight parents were 27% more likely to be overweight, showing the relatively small influence of genetics.