Increasing awareness of diabetes—and not an actual increase in prevalence—helps account for the CDC's bloated numbers. CDC researchers writing in Diabetes Care found:
"…increasing attention to obesity and diabetes in both the lay and professional media may have conditioned health care providers to associate extreme obesity with a high risk of undiagnosed diabetes, making them more likely to question obese patients about symptoms and then to perform more testing … A third implication of our findings is that because much diabetes surveillance is based on self-report of diabetes, a simultaneous increase in obesity prevalence and the detection of diabetes among the most obese could complicate our interpretation of historical trend data. In light of these observations, it is possible that the observed increases in self-reported diagnosed diabetes have slightly overestimated the true increase in total diabetes prevalence."A separate team of CDC researchers writes: "The change in prevalence demonstrated by [the BRFSS and NHIS] might reflect other factors such as enhanced detection rather than true increases." The data help substantiate this point. The number of undiagnosed cases of diabetes among obese individuals has decreased from 12.5% in 1980 to just 3.2% in 1999. Writing in Morbidity and Mortality Weekly Report, a group of CDC researchers note:
"Data from the National Health Interview Survey (NHIS) and the Behavioral Risk Factor Surveillance System (BRFSS) have documented steady increases in the prevalence of diabetes. However, these surveys rely only on self-reports of previously diagnosed diabetes and cannot measure the prevalence of undiagnosed diabetes."Fewer undiagnosed cases means that more people in the BRFSS study will report they have diabetes. But the shift from undiagnosed cases to diagnosed cases doesn't indicate any actual increase in the prevalence of the disease. Only the NHANES data—which show a much lower increase—can control for this problem.