This year, the American Medical Association put out a study including data from the National Health and Nutritional Examination Survey (NHANES). The objective was to analyze obesity trends over the span of a decade (2005-2014), this time adjusting the data to include components of sex, age, race, smoking status and education.
The reason for the study: Previous NHANES data showed little change in obesity among adults in the United states from 1960-1980. However, in the second and third phase of their research (NHANES II and NHANES III) from 1976-1980, and 1988-1994, there was a significant increase in the prevalence of obesity. The reasons for the spike in numbers are unclear. This prompted the study to include other factors.
In addition to the components mentioned above, pregnant women were excluded from analysis. Participants’ ages were also being grouped into categories of 20 to 39 years, 40 to 59 years, and 60 years and older.
Ethnicities were put into the follow categories: Hispanic white, non-Hispanic black, non-Hispanic Asian, Hispanic and other.
The non-Hispanic Asian category included predominantly individuals of Chinese, South Asian, Filipino, Vietnamese and Japanese descent.
Multi-racial participants were put into a separate category.
- Self-reported smoking status was categorized as never-smokers, former smokers and current smokers.
- Never-smokers: Smoked less than 100 cigarettes in their lifetime
- Former smokers: Smoked as many as 100 cigarettes but were not current smokers.
- Current smokers: Those who reported that they smoke every day or some days.
- Less than a high school education
- High school graduate
- Post-secondary education
Findings and Conclusions
- The prevalence of obesity in 2013-2014 among men differed significantly by race/Hispanic origin and by smoking status but not by age group or education.
- The prevalence of obesity among non-Hispanic Asian men was significantly lower than among non-Hispanic white men.
- Among women, the prevalence of obesity in 2013-2014 varied significantly by age group, race/ Hispanic origin, and education but not by smoking status.
- The prevalence of class 3 obesity among men did not differ by age group, race/Hispanic origin, smoking status, or education.
- The prevalence of class 3 obesity among women differed by age and race/Hispanic origin but not by smoking status or education.
The main findings show that there was an overall increased prevalence of obesity (a body mass index of 30), and class 3 obesity (a body mass index of 40).
The conclusions: The age-adjusted prevalence of obesity in 2013-2014 was 35.0% among men and 40.4% among women. The corresponding values for class 3 obesity were 5.5 % for men and 9.9% for women.
Between 2005 and 2014, the prevalence of overall and class 3 obesity showed significant increase for women while there were no significant increase trends for men.