CONTEXT:

Between 1980 and 1999, the prevalence of adult obesity (body mass index [BMI] ≥30) increased in the United States and the distribution of BMI changed. More recent data suggested a slowing or leveling off of these trends.

OBJECTIVE:

To estimate the prevalence of adult obesity from the 2009-2010 National Health and Nutrition Examination Survey (NHANES) and compare adult obesity and the distribution of BMI with data from 1999-2008.

DESIGN, SETTING, AND PARTICIPANTS:

NHANES includes measured heights and weights for 5926 adult men and women from a nationally representative sample of the civilian noninstitutionalized US population in 2009-2010 and for 22,847 men and women in 1999-2008.

MAIN OUTCOME MEASURES:

The prevalence of obesity and mean BMI.

RESULTS:

In 2009-2010 the age-adjusted mean BMI was 28.7 (95% CI, 28.3-29.1) for men and also 28.7 (95% CI, 28.4-29.0) for women. Median BMI was 27.8 (interquartile range [IQR], 24.7-31.7) for men and 27.3 (IQR, 23.3-32.7) for women. The age-adjusted prevalence of obesity was 35.5% (95% CI, 31.9%-39.2%) among adult men and 35.8% (95% CI, 34.0%-37.7%) among adult women. Over the 12-year period from 1999 through 2010, obesity showed no significant increase among women overall (age- and race-adjusted annual change in odds ratio [AOR], 1.01; 95% CI, 1.00-1.03; P = .07), but increases were statistically significant for non-Hispanic black women (P = .04) and Mexican American women (P = .046). For men, there was a significant linear trend (AOR, 1.04; 95% CI, 1.02-1.06; P < .001) over the 12-year period. For both men and women, the most recent 2 years (2009-2010) did not differ significantly (P = .08 for men and P = .24 for women) from the previous 6 years (2003-2008). Trends in BMI were similar to obesity trends.

CONCLUSION:

In 2009-2010, the prevalence of obesity was 35.5% among adult men and 35.8% among adult women, with no significant change compared with 2003-2008.