Trends in Waist Circumference among U.S. Adults

OBJECTIVE: Waist circumference has been proposed as a measure of obesity or as an adjunct to other anthropometric measures to determine obesity. Our objective was to examine temporal trends in waist circumference among adults in the U.S. RESEARCH METHODS AND PROCEDURES: We used data from 15,454 participants >/=20 years old in National Health and Nutrition Examination Survey (NHANES) III (1988 to 1994) and 4024 participants >/=20 years old from National Health and Nutrition Examination Survey 1999 to 2000. RESULTS: The unadjusted waist circumference increased from 95.3 (age-adjusted, 96.0 cm) to 98.6 (age-adjusted, 98.9 cm) cm among men and from 88.7 (age-adjusted 88.9 cm) to 92.2 (age-adjusted 92.1 cm) cm among women. The percentiles from the two surveys suggest that much of the waist circumference distribution has shifted. Statistically significant increases occurred among all age groups and racial or ethnic groups except men 30 to 59 years old, women 40 to 59 and >/=70 years old, and women who were Mexican American or of "other" race or ethnicity. DISCUSSION: These results demonstrate the rapid increase in obesity, especially abdominal obesity, among U.S. adults. Unless measures are taken to slow the increase in or reverse the course of the obesity epidemic, the burden of obesity-associated morbidity and mortality in the U.S. can be expected to increase substantially in future years.