Millions of poor children in the United States may be getting fat before age 10 because their mothers are stressed out and the youngsters seek escape in unhealthy comfort food, researchers said on Tuesday.

The stress is rooted in poverty and can be brought on by money woes, work loads, insufficient health insurance and other factors, said Craig Gundersen of the University of Illinois, who led the study.

"People will eat in response to feeling stress," he said in a telephone interview, and in this case children may be eating more in response to stress-related trouble at home.

The findings show there is a need for a firm social safety net for poor families with protections such as food stamps; better financial education to help people better manage money; and adequate health insurance coverage, he said.

Gundersen and colleagues at Iowa State University and Michigan State University looked at data on 841 children in families living below the poverty line who were part of a government nutrition survey conducted from 1999 to 2002.

"We found that the cumulative stress experienced by the child's mother is an important determinant of child overweight," the research team reported in a study published in the September issue of Pediatrics.

Children in stressed homes where there was plentiful food were more likely to be overweight or obese than those living in stressed situations where food was scarce, they added, because while both were reacting to stress, the former group had food available in which to find refuge.

"Children in food-secure households may have a greater ability to consume more 'comfort foods,' which are often unhealthy, in response to the (stress) they experience," they wrote.