Obesity in the United States

Two reports published in the Journal of the American Medical Association by Flegal et al and Ogden et al find that 35% of men and 40% of women and 17% of children and teens were obese as of 2014. The corresponding values for class 3-obesity (morbid) were 5.5% for men, 9.9% for women and 6% for children and teens.

The authors obtained their data from the National Health and Nutrition Examination Survey (NHANES), a cross-sectional, nationally representative health examination survey of the US population that includes measured weight and height.

Obesity in adults was defined when the BMI (body mass index) was ≥30 and class 3 obesity when the BMI was ≥40.

This report is based on data from 2638 adult men (mean age, 46.8 years) and 2817 women (mean age, 48.4 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.

Measurements from 40 780 children and adolescents (mean age, 11.0 years; 48.8% female) between 1988-1994 and 2013-2014 were also analyzed.

Obesity in children was defined as a body mass index (BMI) at or above the sex-specific 95th percentile on the US Centers for Disease Control and Prevention (CDC) BMI-for-age growth charts. Extreme obesity was defined as a BMI at or above 120% of the sex-specific 95th percentile on the CDC BMI-for-age growth charts. Detailed estimates were presented for 2011-2014. Trend analyses between 2005-2006 and 2013-2014 also were conducted.

For women, the prevalence of overall obesity and of class 3 obesity showed significant linear trends for increase between 2005 and 2014; there were no significant trends for men.

The odds of being obese fluctuated with age. The researchers found that 41% of adults in their 40s and 50s were obese, compared with 34% of adults in their 20s and 30s and 39% of adults ages 60 and older.

There were also differences based on race and ethnicity. At one end of the spectrum were Asian Americans, 13% of who were obese. At the other end were African Americans, 48% of whom were obese. In between were Latinos (43%) and whites (36%).,

The two reports suggest that the U.S. obesity epidemic continues to worsen and that efforts to encourage Americans to lose or stop putting on more weight are having little effect.