Information Sheets

June 2009

 

NCHS Data on Obesity

 

PDF version (87 KB)

 

About NCHS

The CDC's National Center for Health Statistics (NCHS) is the nation's principal health statistics agency, providing data to identify and address health issues. NCHS compiles statistical information to help guide public health and health policy decisions.  

Collaborating with other public and private health partners, NCHS employs a variety of data collection mechanisms to obtain accurate information from multiple sources. This process provides a broad perspective to help us understand the population's health, influences on health, and health outcomes.

 

Overview

The prevalence of obesity continues to be an important public health issue in the U.S. The primary data source for monitoring the national prevalence of obesity is NCHS’ National Health and Nutrition Examination Survey (NHANES). This survey obtains measured (as opposed to self-reported) data on height and weight. Obesity is defined using body mass index (BMI) or weight in kilograms divided by height in meters squared, although definitions are different for adults and children.  

Obesity is associated with increased risk of a number of conditions, including diabetes, cardiovascular disease, hypertension, and certain cancers, and with an increased risk of disability.  

Obesity is a consequence of increased caloric intake and decreased physical activity. The prevalence of obesity is also influenced by environmental factors such as the availability of healthy food options and opportunities for physical activity.

 

Obesity among Adults

More than one-third of adults, or over 72 million people, were obese in 2005-2006. This includes 33.3 percent of men and 35.3 percent of women. 

Obesity data from 2003-2006 show racial and ethnic disparities for women but not for men. Among women aged 60 and older, 61 percent of non-Hispanic black women were obese compared with 32 percent of non-Hispanic white women and 37 percent of Mexican American women.

(1) significantly different from the non-Hispanic white population
(2) significantly different from the non-Hispanic white and Mexican American  population 
NOTE:  obesity is defined as body mass index ≥ 30
Source:  National Health and Nutrition Examination Survey, 2003-2006

 

Obesity among Adolescents

Obesity or high body mass index among adolescents in the U.S. continues to be a public health concern. In 2003-2006, 17.6 percent of adolescents had high BMI-for-age.

 Data for 2003-2006 show:

• Among boys aged 12-19, Mexican Americans were more likely to have high BMI-for-age than non-Hispanic whites.
• Non-Hispanic black and Mexican American teen girls were more likely to have high BMI-for-age when compared with non-Hispanic white teens.

 

Source:  National Health and Nutrition Examination Survey, 2003–2006.

 

Health Education

Health education on weight reduction and exercise are services ordered or provided at many visits to health care providers. Data from the 2006 National Ambulatory Medical Survey and the National Hospital Ambulatory Medical Care Survey show:

• Health education on weight reduction was ordered or provided at 3.3 percent of all hospital outpatient department visits and at 3.7 percent of all physician office visits.
• Health education on exercise was ordered or provided at 7.5 percent of all hospital outpatient department visits and at nearly 10 percent of all physician office visits.

 

Obesity Data Sources

NCHS employs a variety of data collection mechanisms to obtain accurate information from multiple sources. They include:

• National Health and Nutrition Examination Survey (NHANES) – collects information about the health and diet of people in the U.S. NHANES is unique in that it combines a home interview with physical examinations and laboratory tests conducted in a Mobile Examination Center. NHANES can directly measure conditions and provide reliable information on health conditions regardless of whether the survey respondent is aware of them. (NHANES Website)
• National Health Care Surveys – a family of provider surveys, obtaining information about the facilities that supply health care, the services rendered, and the characteristics of the patients served. NCHS surveys hospitals, office-based physician practices, emergency and outpatient departments, ambulatory surgery centers, nursing homes, and home health and hospice agencies.

For further information about NCHS and its programs, visit the NCHS Website, or call the Office of Planning, Budget and Legislation at 301-458-4100.