Frances E. Thompson

Need for Technological Innovation in Dietary Assessment

In 2007, the National Institutes of Health developed the Genes, Environment and Health Initiative (GEI) (www.gei.nih.gov) to promote research to better understand the genetic and environmental contributions to health and disease. GEI funded technology-driven methodology to improve measures of diet, physical activity, chemical exposures, psychosocial measures, and biological response indicators for use in future large-scale population studies. Similarly, since 2004, the National Cancer Institute (NCI) has internally funded the development of another technology advance in dietary assessment: an automated self-administered 24-hour dietary recall (ASA). The purpose of this paper is to briefly overview issues related to the uses of technology in dietary assessment, as a backdrop for advances in the field.

Cognitive research enhances accuracy of food frequency questionnaire reports: results of an experimental validation study

OBJECTIVE To test whether changing a food frequency questionnaire (FFQ) on the basis of cognitive theory and testing results in greater accuracy. Accuracy was examined for 4 design issues: a) Grouping: asking about foods in a single vs multiple separate questions; b) different forms of a food: asking consumption frequency of each form of a food (eg, skim, 2%, whole milk) vs a nesting approach--asking frequency of the main food (eg, milk) and proportion of times each form was consumed; c) additions (eg, sugar to coffee): asking independent of the main food vs nested under the main foods; d) units: asking frequency and portion size vs frequency of units (eg, cups of coffee). DESIGN Participants in two randomly assigned groups completed 30 consecutive daily food reports (DFRs), followed by 1 of 2 FFQs that asked about foods consumed in the past month. One was a new, cognitively-based National Cancer Institute (NCI) Diet History Questionnaire; the other was the 1992 NCI-Block Health Habits and History Questionnaire. SUBJECTS/SETTING 623 participants, age range 25 to 70 years, from metropolitan Washington, DC. Statistical analyses performed Accuracy was assessed by comparing DFR and FFQ responses using categorical (percent agreement) and continuous (rank order correlation, discrepancy scores) agreement statistics. RESULTS Grouping: accuracy was greater using separate questions. Different forms of food: accuracy was greater using nesting. Additions: neither approach was consistently superior; accuracy of the addition report was affected by accuracy of the main food report. Units: both approaches were similarly accurate. CONCLUSIONS Accuracy of FFQ reporting can be improved by restructuring questions based on cognitive theory and testing.

The Automated Self-Administered 24-Hour Dietary Recall (ASA24): A Resource for Researchers, Clinicians, and Educators from the National Cancer Institute

Extensive evidence has demonstrated that 24-hour dietary recalls (24HDRs) provide high-quality dietary intake data with minimal bias, making them the preferred tool for monitoring the diets of populations and, increasingly, for studying diet and disease associations (1-3). Traditional 24HDRs, however, are expensive and impractical for large-scale research because they rely on trained interviewers, and multiple administrations are needed to estimate usual intakes. To address these challenges, the National Cancer Institute (NCI), in collaboration with the research firm Westat (Rockville, MD), and with the support of other institutes and offices at the National Institutes of Health, developed the Automated Self-Administered 24-hour dietary recall (ASA24) (4-6). ASA24 is a public-access, freely available, web-based tool for researchers, clinicians and educators, modeled on the Automated Multiple Pass Method (AMPM) (7). Development of an automated self-administered 24HDR for adults began in 2006 and was informed by input from stakeholders participating in an External Working Group and small-scale cognitive and usability testing (4,5). A Beta version released in August 2009 has been used by over 175 researchers to collect over 40,000 recalls; Version 1, which offers improved usability and new features, was released in September 2011 (8). A modified version intended for self-administration by children is under development by researchers at the Baylor College of Medicine (Houston, TX) and is expected to be available mid-2012 (9,10). This paper describes the features of ASA24 and planned evaluations.

Addressing Current Criticism Regarding the Value of Self-Report Dietary Data

Recent reports have asserted that, because of energy underreporting, dietary self-report data suffer from measurement error so great that findings that rely on them are of no value. This commentary considers the amassed evidence that shows that self-report dietary intake data can successfully be used to inform dietary guidance and public health policy. Topics discussed include what is known and what can be done about the measurement error inherent in data collected by using self-report dietary assessment instruments and the extent and magnitude of underreporting energy compared with other nutrients and food groups. Also discussed is the overall impact of energy underreporting on dietary surveillance and nutritional epidemiology. In conclusion, 7 specific recommendations for collecting, analyzing, and interpreting self-report dietary data are provided: (1) continue to collect self-report dietary intake data because they contain valuable, rich, and critical information about foods and beverages consumed by populations that can be used to inform nutrition policy and assess diet-disease associations; (2) do not use self-reported energy intake as a measure of true energy intake; (3) do use self-reported energy intake for energy adjustment of other self-reported dietary constituents to improve risk estimation in studies of diet-health associations; (4) acknowledge the limitations of self-report dietary data and analyze and interpret them appropriately; (5) design studies and conduct analyses that allow adjustment for measurement error; (6) design new epidemiologic studies to collect dietary data from both short-term (recalls or food records) and long-term (food-frequency questionnaires) instruments on the entire study population to allow for maximizing the strengths of each instrument; and (7) continue to develop, evaluate, and further expand methods of dietary assessment, including dietary biomarkers and methods using new technologies.

Performance of a food-frequency questionnaire in the US NIH–AARP (National Institutes of Health–American Association of Retired Persons) Diet and Health Study

OBJECTIVE We evaluated the performance of the food-frequency questionnaire (FFQ) administered to participants in the US NIH-AARP (National Institutes of Health-American Association of Retired Persons) Diet and Health Study, a cohort of 566 404 persons living in the USA and aged 50-71 years at baseline in 1995. DESIGN The 124-item FFQ was evaluated within a measurement error model using two non-consecutive 24-hour dietary recalls (24HRs) as the reference. SETTING Participants were from six states (California, Florida, Pennsylvania, New Jersey, North Carolina and Louisiana) and two metropolitan areas (Atlanta, Georgia and Detroit, Michigan). SUBJECTS A subgroup of the cohort consisting of 2053 individuals. RESULTS For the 26 nutrient constituents examined, estimated correlations with true intake (not energy-adjusted) ranged from 0.22 to 0.67, and attenuation factors ranged from 0.15 to 0.49. When adjusted for reported energy intake, performance improved; estimated correlations with true intake ranged from 0.36 to 0.76, and attenuation factors ranged from 0.24 to 0.68. These results compare favourably with those from other large prospective studies. However, previous biomarker-based studies suggest that, due to correlation of errors in FFQs and self-report reference instruments such as the 24HR, the correlations and attenuation factors observed in most calibration studies, including ours, tend to overestimate FFQ performance. CONCLUSION The performance of the FFQ in the NIH-AARP Diet and Health Study, in conjunction with the studys large sample size and wide range of dietary intake, is likely to allow detection of moderate (> or =1.8) relative risks between many energy-adjusted nutrients and common cancers.

Assessment of the Accuracy of Portion Size Reports Using Computer-Based Food Photographs Aids in the Development of an Automated Self-Administered 24-Hour Recall

OBJECTIVE To assess the accuracy of portion-size estimates and participant preferences using various presentations of digital images. DESIGN Two observational feeding studies were conducted. In both, each participant selected and consumed foods for breakfast and lunch, buffet style, serving themselves portions of nine foods representing five forms (eg, amorphous, pieces). Serving containers were weighed unobtrusively before and after selection as was plate waste. The next day, participants used a computer software program to select photographs representing portion sizes of foods consumed the previous day. Preference information was also collected. In Study 1 (n=29), participants were presented with four different types of images (aerial photographs, angled photographs, images of mounds, and household measures) and two types of screen presentations (simultaneous images vs an empty plate that filled with images of food portions when clicked). In Study 2 (n=20), images were presented in two ways that varied by size (large vs small) and number (4 vs 8). SUBJECTS/SETTING Convenience sample of volunteers of varying background in an office setting. STATISTICAL ANALYSES PERFORMED Repeated-measures analysis of variance of absolute differences between actual and reported portions sizes by presentation methods. RESULTS Accuracy results were largely not statistically significant, indicating that no one image type was most accurate. Accuracy results indicated the use of eight vs four images was more accurate. Strong participant preferences supported presenting simultaneous vs sequential images. CONCLUSIONS These findings support the use of aerial photographs in the automated self-administered 24-hour recall. For some food forms, images of mounds or household measures are as accurate as images of food and, therefore, are a cost-effective alternative to photographs of foods.

Nonvitamin, nonmineral dietary supplements: issues and findings from NHANES III.

The Commission on Dietary Supplement Labels encourages nutrition professionals to become knowledgeable about all dietary supplements. The Dietary Supplement Health and Education Act of 1995 (DSHEA) expanded the definition of dietary supplements beyond essential nutrients while distinguishing them from drugs or food additives. In order to give practical advice to consumers and policymakers, dietetics professionals need to understand the implications resulting from this less-restrictive regulatory environment for supplements. Dietetics professionals must also become familiar with claims made by manufacturers, retailers, and others regarding popular nonvitamin, nonmineral (NVNM) supplements, as well as usage prevalence and trends. However, NVNM supplements currently are classified inconsistently, and information on the prevalence of use is limited. Sales data suggest that total intake is increasing, and garlic and ginseng are consistently among the most popular supplements. Reported use of NVNM supplements in the third National Health and Nutrition Examination Survey was highest for garlic and lecithin. The data suggest associations of NVNM supplement use with age and more healthful lifestyles; however, there is also a reported link with higher alcohol consumption and obesity. Associations with education, income, region, and urbanization are not evident from the sales data. Standardized survey procedures regarding question phraseology, referent time period, and supplement categorization--along with use of representative samples--will improve our ability to assess supplement use, prevalence, and trends.

Taking Advantage of the Strengths of 2 Different Dietary Assessment Instruments to Improve Intake Estimates for Nutritional Epidemiology

With the advent of Internet-based 24-hour recall (24HR) instruments, it is now possible to envision their use in cohort studies investigating the relation between nutrition and disease. Understanding that all dietary assessment instruments are subject to measurement errors and correcting for them under the assumption that the 24HR is unbiased for usual intake, here the authors simultaneously address precision, power, and sample size under the following 3 conditions: 1) 1-12 24HRs; 2) a single calibrated food frequency questionnaire (FFQ); and 3) a combination of 24HR and FFQ data. Using data from the Eating at Americas Table Study (1997-1998), the authors found that 4-6 administrations of the 24HR is optimal for most nutrients and food groups and that combined use of multiple 24HR and FFQ data sometimes provides data superior to use of either method alone, especially for foods that are not regularly consumed. For all food groups but the most rarely consumed, use of 2-4 recalls alone, with or without additional FFQ data, was superior to use of FFQ data alone. Thus, if self-administered automated 24HRs are to be used in cohort studies, 4-6 administrations of the 24HR should be considered along with administration of an FFQ.

Performance of the Automated Self-Administered 24-hour Recall relative to a measure of true intakes and to an interviewer-administered 24-h recall

BACKGROUND The Automated Self-Administered 24-hour Recall (ASA24), a freely available Web-based tool, was developed to enhance the feasibility of collecting high-quality dietary intake data from large samples. OBJECTIVE The purpose of this study was to assess the criterion validity of ASA24 through a feeding study in which the true intake for 3 meals was known. DESIGN True intake and plate waste from 3 meals were ascertained for 81 adults by inconspicuously weighing foods and beverages offered at a buffet before and after each participant served him- or herself. Participants were randomly assigned to complete an ASA24 or an interviewer-administered Automated Multiple-Pass Method (AMPM) recall the following day. With the use of linear and Poisson regression analysis, we examined the associations between recall mode and 1) the proportions of items consumed for which a match was reported and that were excluded, 2) the number of intrusions (items reported but not consumed), and 3) differences between energy, nutrient, food group, and portion size estimates based on true and reported intakes. RESULTS Respondents completing ASA24 reported 80% of items truly consumed compared with 83% in AMPM (P = 0.07). For both ASA24 and AMPM, additions to or ingredients in multicomponent foods and drinks were more frequently omitted than were main foods or drinks. The number of intrusions was higher in ASA24 (P < 0.01). Little evidence of differences by recall mode was found in the gap between true and reported energy, nutrient, and food group intakes or portion sizes. CONCLUSIONS Although the interviewer-administered AMPM performed somewhat better relative to true intakes for matches, exclusions, and intrusions, ASA24 performed well. Given the substantial cost savings that ASA24 offers, it has the potential to make important contributions to research aimed at describing the diets of populations, assessing the effect of interventions on diet, and elucidating diet and health relations. This trial was registered at clinicaltrials.gov as NCT00978406.

Observational Epidemiologic Studies of Nutrition and Cancer: The Next Generation (with Better Observation)

It would be of enormous public health importance if diet and physical activity, both modifiable behavioral factors, were causally related to cancer. Nevertheless, the nutritional epidemiology of cancer remains problematic, in part because of persistent concerns that standard questionnaires measure diet and physical activity with too much error. We present a new strategy for addressing this measurement error problem. First, as background, we note that food frequency and physical activity questionnaires require respondents to report “typical” diet or activity over the previous year or longer. Multiple 24-hour recalls (24HR), based on reporting only the previous days behavior, offer potential cognitive advantages over the questionnaires, and biomarker evidence suggests the 24-hour dietary recall is more accurate than the food frequency questionnaire. The expense involved in administering multiple 24HRs in large epidemiologic studies, however, has up to now been prohibitive. In that context, we suggest that Internet-based 24HRs, for both diet and physical activity, represent a practical and cost-effective approach for incorporating multiple recalls in large epidemiologic studies. We discuss (1) recent efforts to develop such Internet-based instruments and their accompanying software support systems; (2) ongoing studies to evaluate the feasibility of using these new instruments in cohort studies; (3) additional investigations to gauge the accuracy of the Internet-based recalls vis-à-vis standard instruments and biomarkers; and (4) new statistical approaches for combining the new instruments with standard assessment tools and biomarkers The incorporation of Internet-based 24HRs into large epidemiologic studies may help advance our understanding of the nutritional determinants of cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1026–32)