Misclassification of cardiometabolic health when using body mass index categories in NHANES 2005-2012.
Level 4 - case-series / case-control
Cross-sectional observational study of national survey data
PubMed 26841729 · doi:10.1038/ijo.2016.17
What was done
Analyzed data from 40,420 US adults aged 18 and older from the nationally representative 2005–2012 National Health and Nutrition Examination Survey (NHANES). Cardiometabolic health status—defined using blood pressure, triglycerides, cholesterol, glucose, insulin resistance, and C-reactive protein—was stratified across standard body mass index (BMI) categories.
What was found
Nearly half of overweight individuals, 29% of obese individuals, and 16% of those with class 2/3 obesity were cardiometabolically healthy. In contrast, over 30% of normal-weight individuals were cardiometabolically unhealthy. There was a significant gender-by-BMI interaction (F(4,64) = 3.812, P = 0.008) and no significant race-by-BMI interaction. Relying solely on BMI categories misclassified the cardiometabolic health status of an estimated 74,936,678 US adults.
Why it matters
Using BMI as a primary indicator of health misidentifies metabolic risk in millions of both normal-weight and higher-weight individuals. This demonstrates the flaws of tying health insurance costs or workplace penalties strictly to BMI thresholds.
Limits
The cross-sectional design prevents evaluation of longitudinal disease progression, cardiovascular events, or mortality. Specific diagnostic threshold cutoffs used to define cardiometabolic health were not detailed in the abstract.
Cited by
- contradicts There are more metabolically unhealthy normal-weight individuals in the United States than metabolically unhealthy obese individuals.