The prevalence of obesity and overweight increased in the United States between 1978
and 1991. More recent reports have suggested continued increases but are based on
To examine trends and prevalences of overweight (body mass index [BMI] > or = 25)
and obesity (BMI > or = 30), using measured height and weight data.
Survey of 4115 adult men and women conducted in 1999 and 2000 as part of the National
Health and Nutrition Examination Survey (NHANES), a nationally representative sample
of the US population.
Age-adjusted prevalence of overweight, obesity, and extreme obesity compared with
prior surveys, and sex-, age-, and race/ethnicity-specific estimates.
The age-adjusted prevalence of obesity was 30.5% in 1999-2000 compared with 22.9%
in NHANES III (1988-1994; P<.001). The prevalence of overweight also increased during
this period from 55.9% to 64.5% (P<.001). Extreme obesity (BMI > or = 40) also increased
significantly in the population, from 2.9% to 4.7% (P =.002). Although not all changes
were statistically significant, increases occurred for both men and women in all age
groups and for non-Hispanic whites, non-Hispanic blacks, and Mexican Americans. Racial/ethnic
groups did not differ significantly in the prevalence of obesity or overweight for
men. Among women, obesity and overweight prevalences were highest among non-Hispanic
black women. More than half of non-Hispanic black women aged 40 years or older were
obese and more than 80% were overweight.
The increases in the prevalences of obesity and overweight previously observed continued
in 1999-2000. The potential health benefits from reduction in overweight and obesity
are of considerable public health importance.