1 in 3 US Adults, 1 in 6 US Children Obese

Laura Newman, MA

January 17, 2012

January 17, 2012 — The US prevalence of obesity continues to be high, with one third of US adults and 1 in 6 US children and adolescents affected, according to 2009 to 2010 data from the National Health and Nutrition Examination Survey (NHANES). The data were presented in 2 papers published online January 17 in JAMA. As alarming as these rates are, the data suggest that they may be topping out, according to the researchers.

"[Obesity prevalence] increased significantly over the 12-year period from 1999 through 2010 for men and for non-Hispanic black and Mexican American women, but did not change between 2003-2009 and 2010 for men or women," write Katherine M. Flegal, PhD, distinguished consultant from the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention, Hyattsville, Maryland, and colleagues in the first article.

In addition, trends in US children and teenagers followed a similar pattern — unchanged, but at 17% — since the last review of 2007-2008, explain Cynthia L. Ogden, PhD, MRP, NCHS epidemiologist, and colleagues in the second article, on children and teenagers. Noting the linear increase in obesity prevalence in children, and predictions that obesity prevalence among children and teenagers may reach 30% by 2030, the authors write that "the data presented herein suggest that the rapid increases in obesity prevalence seen in the 1980s and 1990s have not continued in this decade and may be leveling off."

Among US adults, the age-adjusted obesity prevalence was 35.7% (95% confidence interval [CI], 33.8% - 37.7%). Non-Hispanic black men and women had the highest obesity prevalence rates, at 38.8% (95% CI, 33.9% - 43.9%) for men and 58.5% (95% CI, 52.4% - 64.3%) for women. When age-adjusted prevalence of overweight and obesity were combined (body mass index [BMI] of at least 25 kg/m2), it was 68.8% overall (95% CI, 65.9% - 71.5%), 73.9% for men (95% CI, 70.0% - 77.8%), and 63.7% among women (95% CI, 60.9% - 66.4%. Grade 2 obesity, defined as a BMI of 35 kg/m2 or more, and grade 3 obesity (BMI, 40 kg/m2 or more) again show the highest rates for non-Hispanic blacks, at 20.0% (95% CI, 16.4% - 24.3%) for non-Hispanic black men and 30.7% (95% CI, 26.4% - 35.2%) for non-Hispanic black women.

In the study of children and teenagers, investigators used high weight for recumbent length (BMI 95th percentile or higher of the BMI-for-age growth charts). Between 2009 and 2010, 16.9% of US children and adolescents were obese (95% CI, 15.4% - 18.4%), with 31.8% either overweight or obese (95% CI, 29.8% - 33.7%). Boys were consistently more likely to be obese than girls, at 18.6% vs 15.0%. =Racial differences were also striking, with black children and adolescents having an obesity of prevalence of 24.3% (95 CI, 20.5% - 28.6%) compared with 21.2% (95 CI, 19.5% - 23.0%) for Hispanics and 14.0% (95% CI, 11.7% - 16.7%) for non-Hispanic whites. Older children had higher prevalence rates than each successive younger age group.

NHANES analyses are based on at-home interviews and physical examinations collected continuously since 1999 in children, and since 1960 in adults, and released in 2-year cycles. NHANES is designed as a cross-sectional survey nationally representative of the US noninstitutionalized population. Data from other industrialized countries also suggest that obesity trends may be leveling off worldwide.

The authors have disclosed no relevant financial relationships.

JAMA. Published online January 17, 2012. Flegal full text, Ogden full text


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