Using data from a government health database, the researchers discovered that 9.7 percent of people with incomes above $60,000 were obese in the 1970s. That figure leaped to 26.8 percent in 2002.
"This is a very surprising finding," said Dr. Jennifer Robinson of the University of Iowa, the authori of the study that was presented at the meeting of the American Heart Association.
In the 1970s, 22.5 percent of people with incomes below $25,000 were obese.
By 2002, 32.5 percent of the poor were obese. For purposes of comparison, all the income figures were adjusted to reflect year 2000 dollars.
Fresh produce and other healthy foods can be expensive as well as less accessible than fast food and other high-fat options in low-income neighborhoods.
