Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM
JAMA. 2006;296(13):1549-1555.
Background:
Obesity continues to be a leading public health concern in the United States. Between 1980 and 2002, obesity prevalence doubled in adults aged 20 years or older, and overweight prevalence tripled in children and adolescents aged 6 to 19 years.
Objective:
The purpose of this study was to provide current estimates of the prevalence and trends of overweight in children and adolescents and obesity in adults.
Methods:
Prevalence estimates of overweight and obesity were calculated using data from the National Health and Nutrition Examination Survey (NHANES), a complex multistage probability sample of the US civilian, noninstitutionalized population. Analysis of height and weight measurements from 3,958 children and adolescents aged 2 to 19 years and from 4,431 adults aged 20 years or older were obtained in 2003 to 2004. Among children and adolescents, overweight and at risk for overweight were defined based on the sex-specific body mass index (BMI) for age growth charts from the Centers for Disease Control and Prevention. For adults, overweight was defined as a BMI of 25.0 to 29.9, obesity as a BMI of 30.0 or higher, and extreme obesity as a BMI of 40.0 or higher. Data from the NHANES obtained in 1999 to 2000 and in 2001 to 2002 were compared with data from 2003 to 2004.
Results:
In 2003 to 2004, 17.1% of US children and adolescents were overweight and 32.2% of adults were obese. Tests for trends were significant for male and female children and adolescents, indicating an increase in the prevalence of overweight in female children and adolescents from 13.8% in 1999 to 2000 to 16.0% in 2003 to 2004 and an increase in the prevalence of overweight in male children and adolescents from 14.0% to 18.2%. Among adult men, the prevalence of obesity increased significantly between 1999 to 2000 (27.5%) and 2003 to 2004 (31.1%). Among women, no significant increase in obesity was observed. The prevalence of extreme obesity (BMI = 40) in 2003 to 2004 was 2.8% in men and 6.9% in women. Approximately 30% of non-Hispanic white adults were obese as were 45.0% of non-Hispanic black adults and 36.8% of Mexican Americans. Similar to previous analyses, there continues to be differences in overweight and obesity prevalence by race/ethnicity among women and among children and adolescents. Among men, however, the prevalence of obesity did not differ by race/ethnicity.
Discussion:
The prevalence of overweight among children and adolescents and obesity among men increased significantly during the 6-year period from 1999 to 2004. Among women, there was no overall increase in the prevalence of obesity. There is little indication that the prevalence is decreasing in any subgroup of the population.
Comment:
These estimates from the NHANES conducted in 2003 to 2004 represent the most recent prevalence estimates of overweight and obesity in the United States. It is disheartening to see the continued increase in prevalence estimates among adult men and particularly among children and adolescents. Although the estimates seem to be leveling off for adult women in general, a closer review of the data shows the continued increased risk among specific ethnic groups. Among non-Hispanic black women for instance, the odds ratio for obesity was 2.01 (confidence interval, 1.76-2.29), and almost 58% of non-Hispanic black women aged 40 to 59 years were obese. Aggregate data could mask undesirable trends in specific ethnic groups, and this article underscores the importance of describing differences in risk by ethnicity. We still have a long way to go in the fight against this epidemic. Increased resources and emphasis on obesity prevention are critically necessary if we are to get any headway in this battle.
SL