Prevalence of obesity in the United States

The prevalence of overweight and obesity among children and adolescents and obesity among men increased significantly between 1999 and 2004, according to a study in JAMA: Journal of the American Medical Association.

Obesity continues to be a leading public health concern in the United States. Between 1980 and 2002, obesity prevalence doubled in adults aged 20 years or older and overweight prevalence tripled in children and adolescents aged 6 to 19 years, according to background information in the article.

Cynthia L. Ogden, Ph.D., of the Centers for Disease Control and Prevention, Hyattsville, Md., and colleagues examined data on national measurements of weight and height in 2003-2004 and compared these data with estimates from 1999-2000 and 2001-2002 to determine if the overweight trend is continuing. The data consisted of weight and height measurements from 3,958 children and adolescents aged 2 to 19 years and 4,431 adults aged 20 years or older obtained in 2003-2004 as part of the National Health and Nutrition Examination Survey (NHANES), a nationally representative sample of the U.S. population. Overweight among children and adolescents was defined as at or above the 95th percentile of the sex-specific body mass index (BMI) for age growth charts based on data collected between 1963 and 1994. Body mass index is calculated as weight in kilograms divided by the square of height in meters. Obesity among adults was defined as a BMI of 30 or higher; extreme obesity was defined as a BMI of 40 or higher.

The researchers found that 17.1 percent of children and adolescents aged 2 to 19 years were overweight and 32.2 percent of adults aged 20 years or older were obese in 2003-2004. The prevalence of extreme obesity among adults was 4.8 percent. There was a significant increase in the prevalence of overweight in female children and adolescents from 13.8 percent in 1999-2000 to 16 percent in 2003-2004. There was also an increase in the prevalence of overweight in male children and adolescents from 14.0 percent to 18.2 percent.

Among men, the prevalence of obesity increased significantly between 1999-2000 (27.5 percent) and 2003-2004 (31.1 percent). Among women, no significant increase in obesity was observed between 1999-2000 (33.4 percent) and 2003-2004 (33.2 percent). The prevalence of extreme obesity in 2003-2004 was 2.8 percent in men and 6.9 percent in women.

In 2003-2004, significant differences in obesity prevalence remained by race/ethnicity and by age. Approximately 30 percent of non-Hispanic white adults were obese as were 45 percent of non-Hispanic black adults and 36.8 percent of Mexican Americans. Among adults aged 20 to 39 years, 28.5 percent were obese while 36.8 percent of adults aged 40 to 59 years and 31.0 percent of those aged 60 years or older were obese in 2003-2004.

"There is little indication that the prevalence is decreasing in any subgroup of the population. These prevalence estimates, based on a 6-year period (1999-2004), suggest that the increases in body weight may be leveling off in women," the authors write.