Academy Comments to CDC re Revisions to NHANES Survey

July 22, 2016

Leroy A. Richardson
Chief, Information Collection Review Office
Centers for Disease Control and Prevention
1600 Clifton Road NE., MS-D74
Atlanta, Georgia 30329

Re: National Health and Nutrition Examination Survey (NHANES) Revision of Interview Questions and Measurement Parameters (Docket No. CDC-2015-0044)

Dear Mr. Richardson,

The Academy of Nutrition and Dietetics (the "Academy") appreciates the opportunity to submit comments to the Centers for Disease Control and Prevention (CDC) regarding its May 23, 2016 proposed data collection for the National Health and Nutrition Examination Survey (NHANES) Revision of Interview Questions and Measurement Parameters (Docket No. CDC-2015-0044). Representing over 100,000 registered dietitian nutritionists (RDNs),1 nutrition dietetic technicians, registered (NDTRs), and advanced-degree nutritionists, the Academy is the largest association of food and nutrition professionals in the United States and is committed to improving the nation’s health through food and nutrition across the lifecycle. Every day we work with Americans in all walks of life — from prenatal care through end of life care — providing nutrition care services and conducting nutrition research.

The Academy supports the use of dietary surveillance data such as the National Health and Nutrition Examination Survey (NHANES) to contribute to the body of evidence used in forming conclusions about the determinants of public health. Observational data provides a unique perspective on the daily lives of thousands of Americans that would simply not be available in a timely or cost-effective manner from traditional clinical trials. We note that many of the same methods applied to dietary surveillance today were applied in the past to successfully identify smoking as a cause of lung cancer and, thus, a significant public health hazard. The success of public health initiatives, informed by observational research, in reducing smoking strongly supports the rationale for inclusion of similar techniques in developing future dietary guidelines.

Although there are limitations to observational data, many of the specific criticisms leveled against NHANES — particularly that underreporting in dietary assessments undermines the validity of the data — have been muted when the criticisms are analyzed in detail. Criticisms of NHANES have been found to be exaggerated, based on flawed methodologies, and awash in conflicts of interest. Furthermore, we have recently demonstrated that the methods for estimating energy needs upon which the criticism levied by Archer, Hand, and Blair3 depend, are far too imprecise to provide any credible support for their conclusions.4 Underreporting is also unlikely to interfere with the use of findings from NHANES data to support the Dietary Guidelines Advisory Committee's conclusions. In fact, underreporting would most likely serve the bias findings towards the null hypothesis and smaller effect sizes, thereby causing estimates and conclusions to be more conservative.5

The Academy appreciates the opportunity to comment on the proposed data collection regarding the NHANES revision. We would be grateful for the opportunity to discuss these recommendations in greater detail in the near future with you. Please contact either Jeanne Blankenship at 312/899-1730 or by email at or Pepin Tuma at 202/775-8277, ext. 6001 or by email at with any questions or requests for additional information.


Jeanne Blankenship, MS, RDN
Vice President
Policy Initiatives and Advocacy
Academy of Nutrition and Dietetics

Pepin Andrew Tuma, Esq.
Senior Director
Government & Regulatory Affairs
Academy of Nutrition and Dietetics

1 The Academy approved the optional use of the credential "registered dietitian nutritionist (RDN)" by "registered dietitians (RDs)" to more accurately convey who they are and what they do as the nation’s food and nutrition experts. The RD and RDN credentials have identical meanings and legal trademark definitions.

2 Proctor RN. The history of the discovery of the cigarette-lung cancer link: evidentiary traditions, corporate denial, global toll. Tob Control [Internet]. BMJ Publishing Group Ltd; 2012 Mar [cited 2016 Jul 5];21(2):87–91.

3 Archer E, Hand G a, Blair SN. Validity of U.S. Nutritional Surveillance: National Health and Nutrition Examination Survey Caloric Energy Intake Data, 1971-2010. PLoS One [Internet]. 2013 Jan [cited 2013 Nov 6];8(10):e76632.

4 Murphy WJ. The Imprecision of Predictive Equations for Energy Needs: Statistical Inference of the Margin of Error for Individuals. FASEB J. Federation of American Societies for Experimental Biology; 2016;30(1 Supplement):lb382–lb382.

5 Jepsen P, Johnsen SP, Gillman MW, Sørensen HT. Interpretation of observational studies. Heart [Internet]. 2004 Aug [cited 2016 Jul 5];90(8):956–60.