NCHS Data Brief

Cynthia L. Ogden, Ph.D.; Margaret D. Carroll, M.S.P.H.; Margaret A. McDowell, M.P.H., RD; and 

Katherine M. Flegal, Ph.D., Division of Health and Nutrition Examination Surveys

Obesity Among Adults in the United States— 

No Statistically Significant Change Since 2003-2004

No. 1 November 2007

Highlights

Data from the National 

Health and Nutrition 

Examination Survey

► More than one-third of 

U.S. adults were obese in 

2005–2006. This includes 

33.3% of men and 35.3% 

of women.

► Obesity rates have 

increased since the 

1976–1980 survey period. 

There was no signifi cant 

change in obesity

prevalence, however,

between 2003–2004 and 

2005–2006 for either men

or women.

► Recent data show

racial and ethnic obesity

disparities for women but

not for men. Non-Hispanic 

black and MexicanAmerican women were

more likely to be obese

than non-Hispanic white 

women.

► Among obese adults, 

approximately two-thirds 

have been told by a health 

care provider that they are 

overweight.

Importance

Obesity continues to be a public health concern in the United States and throughout the world 

(1–4). In the United States, obesity prevalence doubled among adults between 1980 and 2004 

(5,6). Obesity is associated with increased risk of a number of conditions, including diabetes 

mellitus, cardiovascular disease, hypertension, and certain cancers, and with increased risk of 

disability and a modestly elevated risk of all-cause mortality. Although obesity is a consequence 

of complex factors including an increase in the consumption of calories and a decrease in 

physical activity, the prevalence of obesity is infl uenced by environmental factors. In the 

United States, foods are inexpensive and widely available. In addition, food portion 

sizes have increased and individuals are eating out of the home more often. On the other hand, 

opportunities for physical activity may have decreased.

Keywords: obesity ● prevalence ● trends

Findings

How many adults in the United States are obese?

● More than one-third of adults, or over 72 million people, were obese in 2005–2006.

Men Women

Percent

Figure 1. Obesity prevalence, by age and sex, and the Healthy People (HP) 2010 

obesity target, adults aged 20 years and older: United States, 2005–2006

0

10

20

30

40

50

60 and

over

Total 20–39 40–59

HP 2010

target

Age in years

Obesity rates have increased dramatically in the last 25 years and among men, there 

was an increase in obesity prevalence between 1999 and 2006. There was no signifi cant 

change in obesity prevalence, however, between 2003-2004 and 2005-2006 for men or 

women.

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Center for Health Statistics
 

 

 

No. 1 November 2007

NCHS Data Brief 

 No significant difference in obesity existed between men and women. Adults 40–59 years of age 

were more likely to be obese compared with younger and older individuals. Approximately 40%

 of men 40–59 years of age were obese compared with 28.1% of 20–39 year-olds and 32.2% of

 those aged 60 years and older. Among women, 41.1% of those 40–59 years of age were obese,

 whereas 30.5% of younger women 20–39 years of age were obese. No significant difference

 existed between the oldest women (60 years and older) and younger women. 

● The Healthy People (HP) 2010 objective of an obesity prevalence less than 15% has not been

 met for men nor women of any age. 

The HP 2010 target prevalence for obesity is 15% or about one-half the actual level of obesity. 

This target level was last achieved in 1980. In 2005–2006, 34.3% of adults were obese. 

Has obesity among adults increased since 2004? 

● There was no significant increase in the prevalence of obesity between 2003–2004 and 

2005–2006 in the United States. 

0 

10 

20 

30 

40 

1999–2000 2001–2002 2003–2004 2005–2006

Percent 

Figure 2. Trends in obesity by sex, adults aged 20 years and older: 

United States, 1999–2000 through 2005–2006. 

Women 

Men 

Among men, the prevalence was 31.1% in 2003–2004 and 33.3% in 2005–2006. There was no 

statistically significant change. Among women, the prevalence in 2003–2004 was 33.2% and in 

2005–2006 it was 35.3%. Again, these estimates were not statistically different from each other.

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No. 1 November 2007

NCHS Data Brief 

● Changes in the prevalence of obesity do not present a complete picture of the trends in 

 weight (measured by body mass index (BMI)) among U.S. adults. 

A more complete picture can be seen by comparing the distribution of BMI in 1976–1980 with 

the distribution in 2005–2006 for adults 20–74 years of age. Between 1976–1980 and 2005– 

2006 the distribution of BMI shifted to the right but the shift was greatest at the upper percentiles 

 of the distribution. This indicates that the entire adult population is heavier, and the heaviest have 

become much heavier since 1980. 

NHANES 2005–2006 

NHANES 1976–1980 

0 

5 

10 

15 

20 

10 15 20 25 30 35 40 45 50

Percent 

Figure 3. Changes in the distribution of body mass index (BMI) between 1976–1980 

and 2005–2006, adults aged 20–74 years: United States 

SOURCE: CDC/NCHS, National Health and Nutrition Examination Survey (NHANES). 

BMI 

Are some groups more likely to be obese compared with others? 

●		 There were large disparities in obesity prevalence by race-ethnic group among 

women. Non-Hispanic black and Mexican-American women were more likely 

to be obese than white women. Race/ethnic disparities in obesity were not observed 

in men. 

Approximately 53% of non-Hispanic black women and 51% of Mexican-American 

women 40–59 years of age were obese compared with about 39% of non-Hispanic white 

women of the same age. 

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No. 1 November 2007

NCHS Data Brief 

Among women 60 years and older, 61% of non-Hispanic black women were obese compared with 

32% of non-Hispanic white women and 37% of Mexican-American women. Among men, however, 

the prevalence of obesity did not differ significantly by race/ethnic group. 

Non-Hispanic 

black 

Non-Hispanic Mexican American

white 

Percent 

Figure 4. Prevalence of obesity, by age, race/ethnicity, and sex, adults aged 20 years 

and older: United States, 2005–2006 

0 

10 

20 

30 

40 

50 

60 

70 

60 and 

over 

60 and 20–39 40–59

over 

20–39 40–59

Men Women 

Age in years 

(1) 

(1) 

(2) 

Are obese adults told by their health providers that they are overweight? 

●		Among obese adults, just over 65% were ever told by a health care provider that they 

were “overweight.” Obese women were more likely to be told they were “overweight” 

than were men. 

3 

Percent 

Figure 5. Obese adults aged 20 years and older ever told they were overweight by a 

health care provider: United States, 2005–2006 

Men Women 

(1) 

(1) 

0 

20 

40 

60 

80 

100 

Mexican 

American 

non-Hispanic 

black 

non-Hispanic 

white 

Total 
 

No. 1 November 2007

NCHS Data Brief 

Summary 

Over 34% of adults aged 20 years and older are obese, but there has been no significant change 

in the prevalence since 2003–2004. The increasing trend in obesity over the last 25 years is a result 

of a shift in the entire BMI distribution and an increase in the prevalence of those who are extremely 

obese. In addition, disparities continue to exist. 

Non-Hispanic black and Mexican-American women continue to experience a higher prevalence of 

obesity than their non-Hispanic white counterparts. Although approximately two-thirds of obese 

individuals have been told by a health care provider that they are “overweight,” obesity is extremely 

difficult to treat and the prevalence of obesity is not declining. Nonetheless, even without reaching 

ideal weight, research has shown that a moderate amount of weight loss can be beneficial in terms 

of reducing risk factors, such as high blood pressure. Maintenance of weight loss, however, remains 

difficult (7). 

Definitions

Body mass index (BMI) is calculated as weight in kilograms divided by height in meters squared, 

rounded to one decimal place. For adults 20 years or older, obesity is defined as a BMI of 30.0 or 

higher (8). See the table below for examples of obesity at different heights. The Healthy People 2010 

target is 15% obesity. 

Height Weight Range 

5’0” 153 lbs or more 

5’6” 186 lbs or more 

5’9” 203 lbs or more 

Data source 

The National Health and Nutrition Examination Survey (NHANES) data were used for these 

analyses (9). NHANES is designed to monitor the health and nutritional status of the United States 

civilian, noninstitutionalized population. The survey consists of interviews conducted in 

participants’ homes, standardized physical examinations conducted in mobile examination centers, 

and laboratory tests utilizing blood and urine specimens provided by participants during the physical 

examination. 

The NHANES sample is selected through a complex, multistage design that includes selection of 

primary sampling units (counties), household segments within the counties, and finally sample 

persons from selected households. The sample design includes oversampling in order to obtain 

reliable estimates of health and nutritional measures for population subgroups. In 2005–2006, 

African Americans, Mexican Americans, persons with low income, adolescents 12–19 years of age, 

and adults 60 years and older were oversampled. In 1999, NHANES became a continuous survey, 

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No. 1 November 2007

NCHS Data Brief 

fielded on an ongoing basis. Each year of data collection is based on a representative sample 

covering all ages of the civilian, noninstitutionalized population. Public-use data files are released in 

2-year cycles. 

Sample weights, which account for the differential probabilities of selection, nonresponse and 

noncoverage, are incorporated into the estimation process. The race/ethnic estimates were age 

adjusted to the 2000 U.S. standard population using three age groups, 20–39, 40–59, and 60 years 

and older, in order to compare prevalence estimates between race/ethnic population subgroups that 

differ with respect to their age distributions. Statistical tests on differences between 2005–2006 and 

2003–2004 or between subgroups of the population were done using t-tests at the p < 0.05 level. 

All data analyses were performed using the statistical packages SAS version 9.1 

(SAS Institute, Cary, N.C.) and SUDAAN version 9.0 (RTI, Research Triangle Park, N.C.).
 

Acknowledgments 

Data for this report were prepared by the Division of Health and Nutrition Examination 

Surveys, Informatics Branch. This report was edited by Demarius V. Miller, CDC/CCHIS/NCHM/ 

Division of Creative Services, Writer-Editor Services Branch; and layout and graphic production by 

Zorica Tomic-Whalen, CDC/CCHIS/NCHM/Division of Creative Services, NOVA contractor. 

Suggested citation 

Ogden CL, Carroll MD, McDowell MA, Flegal KM. Obesity among adults in the United States— 

no change since 2003–2004. NCHS data brief no 1. Hyattsville, MD: National Center for Health 

Statistics. 2007. 

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3. Flegal KM, Graubard BI, Williamson DF, Gail MH. Excess deaths associated with underweight, 

overweight, and obesity. JAMA. 2005 Apr 20;293(15):1861–7. 

4. Ogden CL, Yanovski SZ, Carroll MD, Flegal KM. The epidemiology of obesity. Gastroenterology. 

2007 May;132(6):2087–102. Review. 

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NCHS Data Brief 

5. Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among U.S. 

adults, 1999–2000. JAMA. 2002 Oct 9;288(14):1723–7. 

6. Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of 

overweight and obesity in the United States, 1999–2004. JAMA. 2006 Apr 5;295(13):1549–55. 

7. Heo M, Faith MS, Pietrobelli A. Resistance to change of adulthood body mass index. 

Int J Obes Relat Metab Disord. 2002 Oct;26(10):1404–5. 

8. Clinical Guidelines on the identification, evaluation, and treatment of overweight and obesity 

in adults—the evidence report. National Institutes of Health. Obes Res. 1998 Sep;6 Suppl 2:51S– 

209S. Erratum in: Obes Res 1998 Nov;6(6):464. Available from: http://www.nhlbi.nih.gov/guidelines/obesity/ob_gdlns.htm (Accessed August 5, 2005). 

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