Obesity Still a Major Problem
For Immediate Release: Friday, April 14, 2006
Contact: NCHS Press Office (301) 458-4800
The latest estimates of overweight children and adolescents and obesity among adults were published in the April 5, 2006, issue of the Journal of the American Medical Association. The estimates are based on measured values of weight and height from the National Health and Nutrition Examination Survey (NHANES), which is conducted by CDC’s National Center for Health Statistics.
In 2003-04, 17.1% of children and adolescents 2-19 years of age (over 12 and a half million) were overweight, and 32.2% of adults (over 66 million) were obese. Almost 5% of adults were extremely obese.
Significant differences in obesity among race or ethnic groups remain. The prevalence of overweight in Mexican-American and non-Hispanic black girls was higher than among non-Hispanic white girls. Among boys, the prevalence of overweight was significantly higher among Mexican Americans than among either non-Hispanic black or white boys. Among adults, similar differences existed. Approximately 30% of non-Hispanic white adults were obese, and 45.0% of non-Hispanic black adults and 36.8% of Mexican American adults were obese.
There were significant differences by age. Adolescents were more likely to be overweight than younger children, and older adults were more likely to be obese than younger adults. The only exception was among adults 80 years and over who were no different than adults 20-39 years of age.
Between 1999 and 2004, there was a significant increase in the prevalence of overweight among girls (13.8% in 1999 to 16.0% in 2004). Similarly, among boys, the prevalence increased significantly from 14.0% in 1999 to 18.2% in 2004. The prevalence of obesity among men also increased significantly from 27.5% to 31.1%. There was no change in obesity among women (33.4% in 1999 to 33.2% in 2004).
Obesity and overweight are a result of an imbalance between food consumed and physical activity. National data have shown an increase in the calorie consumption of adults and no change in physical activity patterns. But obesity is a complex issue related to lifestyle, environment, and genes. Many underlying factors have been linked to the increase in obesity, such as increasing portion sizes; eating out more often; increased consumption of sugar-sweetened drinks; increasing television, computer, electronic gaming time; changing labor markets; and fear of crime, which prevents outdoor exercise. Obese adults are at increased risk of type II diabetes, hypertension, stroke, certain cancers, and other conditions. Overweight adolescents often become obese adults.
Although the United States has the highest prevalence of obesity among the developed nations, it is not alone in terms of trends. Increases in the prevalence of overweight and obesity among children and adults have been observed throughout the world.
The definitions of overweight and obesity are based on body mass index (BMI, weight in kilograms divided by the square of height in meters). Among children and adolescents, overweight is defined as at or above the 95th percentile of the sex-specific BMI for age growth charts. Among adults, obesity is defined as a BMI over 30 and extreme obesity is defined as a BMI over 40.
More information on the study is available on the CDC/NCHS website.
NOTE: BMI is a single number that evaluates an individual's weight status in relation to height. BMI is generally used as the first indicator in assessing body fat and has been the most common method of tracking weight problems and obesity among adults. It is a mathematical formula in which a person's body weight in kilograms is divided by the square of his or her height in meters (i.e., wt/(ht)2. BMI is highly correlated with body fat. The criteria for obesity is the same for both men and women. Someone who is 5'7" is obese at 192 pounds and a person who is 5'11" is obese at 215 pounds. More information is available at: http://www.cdc.gov/nccdphp/dnpa/bmi/index.htm