Obesity is known to run in some families.

New study suggests this link is strongest in siblings - siblings.

The results of the work were recently published online in the American Journal of Preventive Medicine..

American scientists say that the oldest child in a house where there are two children and at least one obese parent has a 2 times greater risk of obesity. But if you have an older brother or sister who is obese, then your personal risk of obesity increases 5 times, regardless of the physique of the parents.. At least that's what scientists at Duke University in Durham (North Carolina) say..

“Siblings have a big impact. Children often copy the behavior of their older brothers or sisters.. Older siblings can have a significant impact on both the eating behavior and physical activity of younger children in the family,” says study lead author Matthew Harding, professor at the Sanford School of Public Policy..

While parents play an important role in shaping a child's health, siblings can be even more important.. For example, a boy with an obese older brother will himself have a risk of obesity of 11 (! ) times more than in the general population.

“We need to understand that children form strong bonds with their siblings, and as we develop strategies for the prevention and treatment of obesity, we need to think carefully about these connections,” Harding said..

For their study, Professor Harding's team collected data on 10,000 American families.. During the analysis, scientists found that the risk of obesity depends on the number of children in the family and their gender..

In particular, in families with one child, where one of the parents is obese, the child's risk of obesity increases by 2.2 times.. Girls in such families have a lower risk of obesity than boys, researchers say.

In families with two children, younger siblings were very much influenced by older ones, especially those of the same sex.. In such families, the risk of obesity in the youngest boy increases by 11.4 times in the presence of an older brother with obesity.. In a similar situation, younger girls have an 8.6-fold increased risk.

Exercise and diet continue to play a key role in preventing obesity in these children.. Harding's team found that an only child is more active and eats less fast food than children with an older sibling..

medbe. en.