Obesity in the U.S. may have leveled off, at around 34% overall (32% for men and 35% for women), according to data published in the Journal of the American Medical Association.

The prevalence of obesity increased in the United States between 1976-1980 and 1988-1994 and again between 1988-1994 and 1999-2000.

The objective of this study was to examine trends in obesity from 1999 through 2008 and the current prevalence of obesity and overweight for 2007-2008.

Researchers analyzed height and weight measurements from 5555 adult men and women aged 20 years or older obtained in 2007-2008 as part of the National Health and Nutrition Examination Survey (NHANES), a nationally representative sample of the U,S. population. Data from the NHANES obtained in 2007-2008 were compared with results obtained from 1999 through 2006.

According to study findings, in 2007-2008, the age-adjusted prevalence of obesity was 33.8% overall, 32.2% among men, and 35.5% among women. The corresponding prevalence estimates for overweight and obesity combined (BMI 25) were 68%, 72.3%, and 64.1%. Obesity prevalence varied by age group and by racial and ethnic group for both men and women.

Over the 10-year period, obesity showed no significant trend among women. For men, there was a significant linear trend, however, the three most recent data points did not differ significantly from each other.

Researchers concluded that in 2007-2008, the prevalence of obesity was 32.2% among adult men and 35.5% among adult women. The increases in the prevalence of obesity previously observed do not appear to be continuing at the same rate over the past 10 years, particularly for women and possibly for men.