WASHINGTON, D.C. -- In the third quarter of 2011, 11% of Americans reported having ever been diagnosed with diabetes. This measurement and the 10.6% that Gallup and Healthways measured in the second quarter of this year are among the lowest levels recorded since 2009. The diabetes rate was below 11% throughout 2008, but then began to increase in 2009 and 2010.
Gallup and Healthways measure the diabetes rate in the United States by asking Americans: "Have you ever been told by a physician or nurse that you have diabetes?" The question does not discern between Type 1 and Type 2 diabetes.
The obesity rate, which has a well-established relationship with the most common form of diabetes -- Type 2 -- also declined slightly in the second and third quarter of this year, with somewhat lower levels in 2011 compared with 2010. Gallup currently measures the obesity rate based on respondents' self-reported height and weight.
The slight downward trend in obesity levels could be related to similar trends in diabetes rates over the same time period. Gallup has found that obese Americans are nearly three times as likely to report having been diagnosed with diabetes as those who are not obese, and that states with the highest obesity rates have much higher diabetes levels than those with the lowest obesity rates.
Diabetes, whether it is Type 1 or Type 2, does not have a cure. So any decline in the percentage of the population reporting diabetes over time is dependent on fewer new cases and a reduction in old cases through mortality. Individuals who have diabetes or prediabetes and lose a significant amount of weight may see a reduction in their symptoms, and therefore may be less likely to report that they have the condition. If this were to happen on a large scale, it could also contribute to a decline in the nation's overall rate of the disease.
By far the most common form of diabetes is Type 2, which is preventable because of its link to controllable behaviors such as eating and exercise habits. Thus, a decline in America's obesity level will likely result in a slow but detectable decrease in the diabetes rate over time. Gallup recently found that more Americans are now normal weight than overweight, and that the obesity level is slightly trending down in 2011. These results are encouraging, but Gallup will continue to monitor diabetes and obesity rates to track whether current trends will continue.
About the Gallup-Healthways Well-Being Index
The Gallup-Healthways Well-Being Index tracks wellbeing in the U.S., U.K., and Germany and provides best-in-class solutions for a healthier world. To learn more, please visit well-beingindex.com.
Results are based on telephone interviews conducted as part of the Gallup-Healthways Well-Being Index surveys each day, with a random sample of at least 1,000 adults, or approximately 84,000 adults per quarter, aged 18 and older, living in all 50 U.S. states and the District of Columbia, selected using random-digit-dial sampling.
For quarterly results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error for diabetes reporting is ±0.3 percentage points.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each sample includes a minimum quota of 400 cell phone respondents and 600 landline respondents per 1,000 national adults, with additional minimum quotas among landline respondents by region. Landline telephone numbers are chosen at random among listed telephone numbers. Cell phone numbers are selected using random-digit-dial methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted by gender, age, race, Hispanic ethnicity, education, region, adults in the household, and phone status (cell phone only/landline only/both, cell phone mostly, and having an unlisted landline number). Demographic weighting targets are based on the March 2010 Current Population Survey figures for the aged 18 and older non-institutionalized population living in U.S. telephone households. All reported margins of sampling error include the computed design effects for weighting and sample design.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
For more details on Gallup's polling methodology, visit http://www.gallup.com/.