Once considered primarily a problem of the poor, obesity now is growing most rapidly among those making more than $60,000 a year, according to University of Iowa researchers.

That's not to say that obesity is not a major problem among lower income people. Those earning less than $25,000 a year continue to have the highest obesity rate.

But in a study presented at the American Heart Association's 45th Annual Conference on Cardiovascular Disease Epidemiology and Prevention, the researchers reported that in the income category above $60,000, the prevalence of obesity increased from 9.7 percent in 1971-1974 to 26.8 percent in 2001-2002 -- an increase of 209 percent.

For those earning $25,000-$39,999, the prevalence was 16.1 percent in 1971-1974 and 31.3 per cent in 2001-2002 -- an increase of 194 percent.

And for those making less than $25,000, the prevalence was 22.5 percent in 1971-1974 and was 32.5 percent in 2001-2002 -- n increase of 144 percent.

"There has been a perception that poor people are more likely to be fat," said presenter Nidhi Maheshwari, M.B.B.S., a graduate research assistant in epidemiology in the University of Iowa College of Public Health at Iowa City. "However, obesity is growing at a much faster rate in those with the highest incomes."

"The inverse relationship between income and obesity seen in earlier studies has eroded," added co-author Jennifer G. Robinson, M.D., M.P.H., associate professor of epidemiology in the University of Iowa. "Obesity prevalence now is similar across all income categories, with obesity prevalence in the highest income group rapidly approaching that of the lowest income group."

Different dynamics are associated with the rise in obesity, she said. "The fact is that obesity is increasing in all races, all income categories and at a faster rate with people in higher incomes. While factors are common to both the rich and the poor, there may be certain factors primarily affecting the poor, and a different set of reasons primarily affecting the rich."

Other sources: Medical Week staff