US obesity rates: astronomical but leveling

The latest National Health and Nutrition Examination Survey (NHANES) data for 2009-2010 reveal that more than 1 in 3 adult men and women in the United States are obese, as are more than 1 in 6 children and adolescents. The good news is that the figures for both adults and children are largely unchanged from previous periods, suggesting a slowing or leveling off of obesity prevalence.

For the period 2009-2010, the age-adjusted mean body mass index (BMI) for men and women was 28.7 (95% Confidence Interval [CI], 28.3-29.1 for men and 28.4-29.0 for women). The age-adjusted prevalence of obesity was 35.7% among adult men and 35.8% among adult women. No significant increase occurred in the prevalence of obesity for women overall during the 12-year period from 1999 to 2010 (adjusted odds ratio [AOR], 1.01; 95% CI, 1.00-1.03; P=.07); however, a statistically significant increase did occur among non-Hispanic black women (P=.04) and among Mexican American women (P=.046). Men demonstrated a significant linear increase over the 12 years (AOR, 1.04; 95% CI, 1.02-1.06; P<.001). For both genders, figures from 2009-2010 did not differ significantly from the previous 6 years (2003-2008).

For the 2009-2010 period, 9.7% (95% CI, 7.6%-12.3%) of infants and toddlers had a high weight for their recumbent length, and 16.9% (95% CI, 15.4%-18.4%) of children between the ages of 2 and 19 years qualified as obese. Although no difference in the prevalence of obesity occurred among males or females between the periods 2007-2008 and 2009-2010, a significant increase occurred between the period 1999-2000 and the period 2009-2010 in males 2 to 19 years of age (OR, 1.05; 95% CI, 1.01-1.10), but not in females (OR, 1.02; 95% CI, 0.98-1.07). Similarly, a significant increase occurred in BMI among adolescent males 12 to 19 years of age (P=.04), but not among males of any other age group or among females.

Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of obesity and trends in body mass index among US children and adolescents, 1999-2010. JAMA. 2012. Epub ahead of print.