Special articleThe Inadmissibility of What We Eat in America and NHANES Dietary Data in Nutrition and Obesity Research and the Scientific Formulation of National Dietary Guidelines
Section snippets
Success, Failure, and Confusion in Nutrition Research
During the past century, our nation’s food supply and the nutritional status of Americans have improved to a level unparalleled in human history.2, 3 Although this reality may be contrary to the popular belief that our modern diet is inherently inadequate, the data are clear. In the early 20th century, nutritional diseases such as pellagra, beriberi, rickets, and goiter were substantial public health challenges. In the United States alone, pellagra (a disease of niacin deficiency) claimed more
A Failed Research Paradigm
Epidemiologic studies suggest that almost any nutrient can be associated with a myriad of outcomes,11, 22 as observed in Schoenfeld and Ioannidis’ article, “Is Everything We Eat Associated With Cancer?”22,p117 With persistent cycles of specious nutrition claims in the media, it is not surprising that the public is confused and incredulous.23 Insofar as the provision of clear and consistent dietary guidelines for the consuming public is a goal of nutrition epidemiology, it has failed in
Purpose of this Review
Memory-based dietary assessment methods (M-BMs) (eg, interviews, questionnaires, and surveys31, 32) are the dominant data collection protocols in national nutrition surveillance33 and government-funded epidemiologic nutrition34 and obesity33 research. Importantly, M-BM data are used to inform national nutritional policy and dietary guidelines.30 The recent Scientific Report of the 2015 Dietary Guidelines Advisory Committee (DGAC) stated explicitly that most of the DGAC data analyses used the
Self-reported Dietary Intake
The primary methods of data collection for nutrition epidemiologic research (eg, the WWEIA-NHANES) are M-BMs (eg, 24-hour dietary recalls [24HRs] and food frequency questionnaires [FFQs]31, 32, 33). For clarity, these methods do not directly or objectively measure EI or nutrient intake, and neither do they directly or objectively measure food and beverage consumption. The actual data derived from M-BMs are the a priori numeric values from nutrient databases that are assigned by researchers to
Overview
The use of M-BMs requires faith in the belief that human perception, memory, and recall are accurate and reliable instruments for the generation of scientific data. Nevertheless, more than 80 years of research demonstrates that this belief is patently false.50, 58, 70, 90 The discrepancy between objective reality and human memory is well established,48, 91 and the limitations of recall are widely acknowledged in disciplines outside of nutrition and obesity.47, 48, 49, 69, 70, 92 In fact, the
False Reporting and FFQs
False reports are the recollection of an event, or details of an event, that did not actually occur.69 False memories and recalls may be produced in multiple contexts (eg, during research,55, 103 psychotherapy, and criminal investigatory interviews60). Although research has demonstrated that false memories of ingestive behavior and subsequent false reporting of foods occur in laboratory settings,55, 61, 103 there is a larger literature base outside of nutrition. The Deese-Roediger and McDermott
Criteria for Scientific Research: Observable, Measurable, and Falsifiable
Although the terms science and research are used interchangeably, they are not synonymous. Science is more than mere data collection; it is an attempt to discover order, a potentially self-correcting, explanatory, and predictive process that demonstrates lawful relations (eg, diets high in vitamin C prevent scurvy). In contrast, research is simply the process of collecting information, and many forms of research do not meet the rigor necessary for the results to be scientific. There is a long
National Nutrition Surveillance: M-BM Data and USDA Food Availability Economic Data
If the 2 major components of US national nutritional surveillance are valid (ie, NHANES M-BM data and USDA Food Availability economic data), estimates from these surveillance tools should track together and independently provide population-level approximations of trends in food consumption or use. Nevertheless, history demonstrates that this is not the case. Trends in estimates of macronutrient consumption from population-level epidemiologic surveys (ie, M-BMs) exhibited statistically
PA and CRF: Essential Elements in Nutrition, Obesity, and Health Research
The lack of explanatory and predictive power of epidemiologic nutrition research may also be explained by the limited acknowledgement of nonnutritional determinants of health and disease, such as nongenetic evolution,6, 7, 8 PA,121, 122 CRF,123 and other components of nutrient partitioning and energy balance.124, 125, 126, 127, 128, 129, 130 For example, more than 50 years ago the Food and Agriculture Organization of the United Nations and the World Health Organization determined that human
Summary and Future Directions
A wise man proportions his belief to the evidence.
David Hume142,p87
This critical review provides empirical and analytic evidence to support the position that (1) M-BM estimates of EI and nutrient intake have trivial relationships with actual EI and nutrient intake; (2) the assumption that human memory and recall provide literal, accurate, or precise reproductions of past ingestive behavior is indisputably false; (3) M-BMs require participants to submit to protocols that mimic procedures known
Conclusion
In this critical review, we argued that the essence of science is the ability to discern fact from fiction, and we presented evidence from multiple fields to support the position that the data generated by nutrition epidemiologic surveys and questionnaires are not falsifiable. As such, these data are pseudoscientific and inadmissible in scientific research. Therefore, these protocols and the resultant data should not be used to inform national dietary guidelines or public health policy, and the
Acknowledgments
The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
References (147)
- et al.
The CDC's Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population is a valuable tool for researchers and policy makers
J Nutr
(2013) The childhood obesity epidemic as a result of nongenetic evolution: the maternal resources hypothesis
Mayo Clin Proc
(2015)The mother of all problems
New Sci
(2015)In reply—Maternal, paternal, and societal efforts are needed to “cure” childhood obesity
Mayo Clin Proc
(2015)- et al.
Self-report-based estimates of energy intake offer an inadequate basis for scientific conclusions
Am J Clin Nutr
(2013) Clinical trials and observational studies to assess the chronic disease benefits and risks of multivitamin-multimineral supplements
Am J Clin Nutr
(2007)- et al.
Dietary fiber and whole-grain consumption in relation to colorectal cancer in the NIH-AARP Diet and Health Study
Am J Clin Nutr
(2007) - et al.
Is everything we eat associated with cancer? a systematic cookbook review
Am J Clin Nutr
(2013) The questionable role of saturated and polyunsaturated fatty acids in cardiovascular disease
J Clin Epidemiol
(1998)- et al.
Is fructose a story of mice but not men?
J Am Diet Assoc
(2011)
Effect of fructose on postprandial triglycerides: a systematic review and meta-analysis of controlled feeding trials
Atherosclerosis
Estimation of usual intakes: What We Eat in America-NHANES
J Nutr
Limitations in the assessment of dietary energy intake by self-report
Metabolism
Undereating and underrecording of habitual food intake in obese men: selective underreporting of fat intake
Am J Clin Nutr
Selective underreporting of energy intake in women: magnitude, determinants, and effect of training
J Am Diet Assoc
Considering the value of dietary assessment data in informing nutrition-related health policy
Adv Nutr
The cognitive neuroscience of memory distortion
Neuron
The distinctions of false and fuzzy memories
J Exp Child Psychol
Understanding nutritional epidemiology and its role in policy
Adv Nutr
Implausible data, false memories, and the status quo in dietary assessment
Adv Nutr
Food intakes of obese and non-obese women
J Am Diet Assoc
Energy adjustment does not control for differential recall bias in nutritional epidemiology
J Clin Epidemiol
Markers of the validity of reported energy intake
J Nutr
The Keynes centenary
The Economist
Nutrient Content of the U.S. Food Supply, 1909-2000
Pellagra in the United States: a historical perspective
South Med J
National Report on Biochemical Indicators of Diet and Nutrition in the US Population 1999–2002
Estimates of Funding for Various Research, Condition, and Disease Categories
Implausible results in human nutrition research
BMJ
Epidemiology faces its limits
Science
Vitamin E consumption and the risk of coronary disease in women
N Engl J Med
Vitamin E consumption and the risk of coronary heart disease in men
N Engl J Med
Persistence of contradicted claims in the literature
JAMA
Deming, data and observational studies
Significance
Concordance Between the Findings of Epidemiological Studies and Randomized Trials in Nutrition: An Empirical Evaluation and Citation Analysis
Beta-carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials
Int J Cancer
Are nutrtion scientists communicating worse or has the situation just gotten more complicated?
Nutr Today
Low sodium intake: cardiovascular health benefit or risk?
N Engl J Med
Epidemiological studies related to coronary heart disease: characteristics of men aged 40-59 in seven countries
Acta Med Scand Suppl
Scientific Report of the 2015 Dietary Guidelines Advisory Committee
Dietary assessment methodology
Nutritional Epidemiology
Validity of U.S. nutritional surveillance: National Health and Nutrition Examination Survey caloric energy intake data, 1971-2010
PLoS One
OPEN about obesity: recovery biomarkers, dietary reporting errors and BMI
Int J Obes (Lond)
Pooled results from 5 validation studies of dietary self-report instruments using recovery biomarkers for energy and protein intake
Am J Epidemiol
Using intake biomarkers to evaluate the extent of dietary misreporting in a large sample of adults: the OPEN study
Am J Epidemiol
Can adverse effects of dietary fat intake be overestimated as a consequence of dietary fat underreporting?
Public Health Nutr
Do we eat less fat, or just report so?
Int J Obes Relat Metab Disord
Cited by (0)
For editorial comment, see page 845
Grant Support: This work was supported by grant T32DK062710 (E.A., G.P.) from the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.
Potential Competing Interests: Dr Archer has received honoraria from the International Life Sciences Institute and The Coca Cola Company. Dr Lavie reports receiving consulting fees and speaking fees from The Coca-Cola Company and writing a book on the obesity paradox with potential royalties.