As the Centers for Disease Control (CDC) found in analyzing data culled from its Behavioral Risk Factor Surveillance System, obesity rates have spread throughout the country. “In 1991,” the CDC notes, “four states had obesity prevalence rates of 15% to 19%, and no states had rates at or above 20%. In 2004, seven states had obesity prevalence rates of 15% to 19%; 33 states had rates of 20% to 24%; and nine states had rates more than 25% (no data for one state).” According to results from the 2003-2004 National Health and Nutrition Examination Survey (NHANES), an estimated 66% of U.S. adults are either overweight or obese. Making matters even worse, a study published in Britain's Journal of the Royal Society of Medicine by Harvard School of Public Health specialists finds these numbers may be significantly lower than reality. Conventional estimates in 2002 pegged 21.9% of men and 21.2% of women as clinically obese; however, the study published in Britain found 28.7% of adult American men and 34.5% of American women actually fell under that banner. Why was there a discrepancy? The study put the blame on low-cost data collection and human nature (that is, the tendency to underestimate one's weight).
Nevertheless, the NHANES study does indicate some positive news on the obesity front. While overweight levels increased among girls and boys, as did obesity levels in men, (by 3% to 4% among each group) between 1999 and 2004, women actually registered a slight decline in obesity (dropping from 33.4% in 1999 to 33.2% in 2004).