Researchers say the prevalence of obesity has more than doubled since 1980 while just being overweight has remained stable over the same period.
The latest figures come from a 2005/2006 survey and are the most current available.
Report: Obese Americans outnumber overweight
January 12, 2009
The study shows more than 34 percent of Americans are obese compared to 32.7 percent who are overweight.
It said just under 6 percent are extremely obese.
