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) Longitudinal Study—Feasibility Component (Docket No. CDC-2016-0043)
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 National Health and Nutrition Examination Survey (NHANES) Longitudinal Study—Feasibility Component (Docket No. CDC-2016-0043). 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.2 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 DGAC 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 2014 study "Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults,"6 in addition to demonstrating the value that past longitudinal NHANES data collection has contributed chronic disease epidemiology, emphasizes the current need for the data collection proposed by CDC and HHS. This study reports a strong association between added sugar intake and cardiovascular mortality, and we highlighted this evidential trend in our comments to HHS and USDA on the Scientific Report of the 2015 Dietary Guidelines Advisory Committee, noting that "the evidence summarized by the DGAC suggests that the most effective recommendation for the reduction in cardiovascular disease would be a reduction in carbohydrate intake with replacement by polyunsaturated fat."7 A subsequent independent review from DiCicolantonio, Lucan, and O’Keafe supported this finding and concluded, “Dietary guidelines should shift focus away from reducing saturated fat and then replacing saturated fat with carbohydrates, specifically when these carbohydrates are refined. To reduce the burden of CHD, guidelines should focus particularly on reducing intake of foods containing concentrated sugars such as ultra-processed foods and beverages."8 The scientific debate on this topic, however, is not settled, and the 2015-2020 Dietary Guidelines for Americans9 include recommendations to reduce both added sugar and saturated fat intakes without prioritizing either. The currently proposed data collection could provide valuable evidence to clarify which target would maximize the effectiveness of public health recommendations and interventions.
It is imperative that any longitudinal NHANES data collection include dietary interviews at the time of follow-up. An analysis of data from the Nurses' Health Study, Nurses' Healthy Study II and Health Professionals Follow-up Study has demonstrated that changes in dietary intake throughout adulthood play an important role in obesity development.10 As obesity is both a targeted outcome of the proposed data collection and a mitigating factor in chronic diseases, the collection of dietary interviews as a part of the longitudinal NHANES data will be vital to describing the relationship between nutrition and health outcomes. The longitudinal study as currently described in the federal register does not presently appear to include a follow-up dietary examination; thus we urge HHS and CDC to include the dietary component in order to provide the best evidence for the determinants of health of the population of the United States.
The Academy appreciates the opportunity to comment on the proposed data collection regarding the NHANES Longitudinal Study Feasibility Component. 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 firstname.lastname@example.org or Pepin Tuma at 202-775/8277 ext. 6001 or by email at email@example.com with any questions or requests for additional information.
Jeanne Blankenship, MS, RDN
Policy Initiatives and Advocacy
Academy of Nutrition and Dietetics
Pepin Andrew Tuma, Esq.
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.
6 Yang Q, Zhang Z, Gregg EW, Flanders WD, Merritt R, Hu FB, et al. Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults. JAMA Intern Med [Internet]. American Medical Association; 2014 Apr 1 [cited 2016 Jul 5];174(4):516.
7 Academy of Nutrition and Dietetics Comments to the Dietary Guidelines Advisory Committee. May 8, 2015. Accessed July 14, 2016.
8 DiNicolantonio JJ, Lucan SC, O’Keefe JH, Roger VL, Go AS, Lloyd-Jones DM, et al. The Evidence for Saturated Fat and for Sugar Related to Coronary Heart Disease. Prog Cardiovasc Dis [Internet]. Elsevier; 2016 Mar [cited 2016 Jul 5];58(5):464–72.
9 U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans, 8th Edition [Internet]. 2015.
10> Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med [Internet]. 2011 Jun 23 [cited 2016 Jul 5];364(25):2392–404.