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Waist circumference is another widely used measurement to determine abdominal fat content.
An excess of abdominal fat, when out of proportion to total body fat, is considered a predictor
of risk factors related to obesity. Men with a waist measurement exceeding 40 inches are
considered at risk. Women are at risk with a waist measurement of 35 inches or greater.
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Other methods of estimating body fat and body fat distribution include measurements of
skinfold thickness and waist circumference, calculation of waist-to-hip circumference ratios, and
techniques such as ultrasound, computed tomography, and magnetic resonance imaging (MRI).
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Rates and Trends in Obesity
Figure 1 shows that as of 1962, about 46% of U.S. adults fell into the categories of
overweight, obesity, and extreme obesity. About 32% of adults were overweight, about 13%
were obese, and about 1% had extreme obesity.
Percentages of adults within all of these categories increased gradually until the late 1970s,
at which point they began to climb more quickly, leveling off somewhat around 2000. At this
point, about 70% of adults were considered overweight, obese, or extremely obese. Of this
group, 34% were considered overweight, about 31% were considered obese, and about 5%
were considered to have extreme obesity.
By 2010, the percentage of adults considered overweight, obese, or extremely obese had
climbed to about 75%, of whom about 33% were considered overweight, about 36% were
considered obese, and about 6% were considered extremely obese.
Figure 1 – Trends in Overweight and Obesity among Adults, United States, 1962-2010
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Source: Ogden & Carroll, 2010; Flegal et al., 2012
Data for 1960–1980 are for adults ages 20 to 74; data for 1988–2010 are for adults age 20 and older.
The prevalence of BMI-defined obesity in adults in the United States continues to exceed 30%
in most sex-age groups. The burden of obesity, however, is disproportionately borne by some
racial and ethnic groups. For women, within race/ethnicity groups, data over a 12-year period
from 1999 through 2010 show that obesity increased significantly for non-Hispanic/Latino
Black and Mexican American women but
not
for women overall. Considering men and women
together, non-Hispanic/Latino Blacks have the highest age-adjusted rates of obesity (49.5%)
compared with Mexican Americans (40.4%), all Hispanics/Latinos (39.1%), and non-Hispanic/
Latino Whites (34.3%).
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