Washington:  Immigrant children in the US are more likely to be sedentary than US-born white kids, which may put them at a higher risk of obesity, a new study suggests.

The researchers at Rice University said their findings should remind pediatricians and parents of children in immigrant families to encourage physical activity.

The research shows that children of immigrants from all racial and ethnic backgrounds have lower levels of physical activity than US-born white children, even when adjustments are made for socio-demographic and neighbourhood characteristics.

A low level of physical activity is zero days in a typical week of exercise that causes rapid breathing, perspiration and a rapid heartbeat for 20 continuous minutes or more.

Children of Asian immigrants are nearly three times as likely to have lower levels of physical activity than US-born white children, and children of Hispanic immigrants and immigrants of unspecified ethnicity are nearly two times as likely.

The study included data from the Early Childhood Longitudinal Study, which surveyed 17,510 participants with kindergartners on issues affecting child development between 1998 and 1999.

The study also found that US-born white children have higher rates of physical activity than minority children born in the US, although the gap is smaller than the one that exists with children of immigrants.

US-born black children are 1.35 times as likely to have lower levels of physical activity, US-born Hispanic children are 1.23 times as likely and US-born children of unspecified ethnicity are 1.52 times as likely.

“Children in immigrant families are at particular risk for low levels of physical activity, which we were unable to explain with a host of factors relating to family and neighbourhood characteristics,” said Rachel Kimbro, an associate professor of sociology at Rice and the study’s co-author.

Mackenzie Brewer, a doctoral student in sociology at Rice University and the study’s lead author, said that in terms of health status in the US, it is important to understand the health behaviours of children in immigrant families.

“These children comprise a growing population of American youth, and failing to address the low levels of physical activity among this group could have important long-term health consequences as this population transitions into adolescence and adulthood,” Brewer said.

The study appears in the journal Social Science and Medicine.