The second reason obesity is a big problem in the U.S. is that it is growing at an alarming rate. A quick look at these maps is all it takes to realize the scope of the obesity problem. Between 1991 and 2004, there was a dramatic increase in the number of people who were obese, and in many American states in 2004, more than a quarter of residents were obese. In fact, the problem may be even worse than it appears in these maps. Data published in 2006 indicate that 32 percent of adults are obese, and, ominously, 17 percent of children are overweight.

Source: Behavioral Risk Factor Surveillance System, CDC.

Ogden et al, JAMA 295:1549-1555, 2006.