Classification of individuals as overweight or obese is improved by employing the adjusted BMI score, predicted from the regression model shown in Table 3. The adjusted BMI score improves the sensitivity of being classified as overweight or more (BMI 25+) to 94.6% (from 91.4%) and the sensitivity of being classified as obese (BMI of 30+) to 91.5% (from 83.3%). Population estimates are also improved, as shown in Table 4. The three NHANES estimates of the percentages of overweight and obese individuals in the population show that the adjusted self-reported measure mirrors the BMI categories based on measured height and weight more closely than the unadjusted self-reported measure. The NHIS, which exclusively relies on interview data, yields a very low estimate of the percentage of obese U.S. residents, even when compared to the interview data from the NHANES. However, after applying the NHANES prediction model to the NHIS to adjust for systematic biases in self-reporting height and weight, population estimates of overweight and obesity among U.S. adults using data from the NHIS more closely approximate the NHANES (measured) estimates, although significant differences remain for the obesity category.
