The study, which was published Monday in the American Medical Association's Archives of Pediatric and Adolescent Medicine, is based on an analysis of a 32-year study of some 4,800 US households.

It concluded that American children face the highest levels of poverty and social deprivation of any children growing up in Western developed nations, and they have the flimsiest social safety net to fall back on.

"It's always been weak, particularly compared with European countries or Canada or other industrialized countries," said Rank, a professor at the school of social work at Washington University in St. Louis, Missouri.

"One of the reasons why our rates of poverty are so high is because we do so little in terms of trying to protect families from getting into poverty. We have to cast our safety net wider," he said.

Poverty and food insecurity are "two of the most detrimental economic conditions affecting a child's health" and tag 22 billion dollars a year onto US health care costs, the study said.

"Children in poverty are significantly more likely to experience a range of health problems, including low birth weight, lead poisoning, asthma, mental health disorders, delayed immunization, dental problems and accidental death," it said.

"There's a strong connection between poverty, health and mental health," said Rank and the detrimental effects of growing up poor, even if just for a short period, often carry over into adulthood, he said.

An earlier study conducted by Rank and Hirschl showed that half of American adults resort to food stamps to put a meal in their stomachs.