Prevalence and Trends in Obesity Among US Adults, 1999-2000

Abstract

Data from the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994) showed that the prevalence of obesity, defined as a body mass index (BMI) of 30 or higher, had increased by approximately 8 percentage points in the United States after being relatively stable from 1960 to 1980.^1,2 Since those data were published, additional reports from other sources have suggested that these trends are continuing.^3-6 However, those reports from the Behavioral Risk Factor Surveillance System (BRFSS) and the Harris Poll have limitations because they are based on self-reported weight and height. Obesity prevalence estimates based on self-reported data tend to be lower than those based on measured data.⁴ For example, the BRFSS showed a prevalence of obesity of 12% to 14.4% during 1991 to 1994⁴; the corresponding NHANES estimate of 22.5% for 1988 to 1994² was more than 50% higher than the BRFSS estimates. National examination survey data based on measured weight and height data provide the best opportunity to track trends in weight in the United States. In this article we report the results from the latest NHANES data from 1999-2000 regarding population trends in obesity and in the frequency distribution of BMI.