The prevalence of obesity in 2013- 2014 was 35 percent among men and 40 percent among women, and between 2005 and 2014, there was an increase in prevalence among women, but not men, according to a study appearing in the June 7 issue of JAMA.
Between 1980 and 2000, the prevalence of obesity increased significantly among adult men and women in the United States; further significant increases were observed through 2003-2004 for men but not women. Subsequent comparisons of data from 2003-2004 with data through 2011-2012 showed no significant increases for men or women. To get a more comprehensive understanding of the trends in obesity, Katherine M. Flegal, Ph.D., of the National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Md., and colleagues examined obesity prevalence for 2013-2014 and trends over the decade from 2005 through 2014, adjusting for sex, age, race/Hispanic origin, smoking status, and education. The researchers analyzed data obtained from the National Health and Nutrition Examination Survey (NHANES), a cross-sectional, nationally representative health examination survey of the U.S. civilian population that includes measured weight and height.
The analysis included data from 2,638 adult men (average age, 47 years) and 2,817 women (average age, 48 years) from the most recent 2 years (2013-2014) of NHANES and data from 21,013 participants in previous NHANES surveys from 2005 through 2012. For the years 2013-2014, the overall age-adjusted prevalence of obesity (body mass index [BMI] 30 or greater) was 38 percent; among men, it was 35 percent; and among women, it was 40 percent. The corresponding prevalence of class 3 (BMI 40 or greater) obesity overall was 7.7 percent; among men, it was 5.5 percent; and among women, it was 9.9 percent. Analyses of changes over the decade from 2005 through 2014, adjusted for age, race/Hispanic origin, smoking status, and education, showed significant increasing linear trends among women for overall obesity and for class 3 obesity but not among men.
Analyses of the data from 2013-2014 found that for men, obesity prevalence varied by smoking status, with the prevalence of obesity significantly lower among current smokers than among never smokers. For women, there were no significant differences by smoking status, but those with education beyond high school were significantly less likely to be obese.
The authors write that although there has been considerable speculation about the causes of the increases in obesity prevalence, data are lacking to show the causes of these trends, and there are few data to indicate reasons that these trends might accelerate, stop, or slow. "Other studies are needed to determine the reasons for these trends."
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