The National Cancer Institute's Dietary Assessment Primer: A Resource for Diet Research.

This monograph describes the National Cancer Institute's Dietary Assessment Primer, a web resource developed to help researchers choose the best available dietary assessment approach to achieve their research objective. All self-report instruments have error, but understanding the nature of that error can lead to better assessment, analysis, and interpretation of results. The Primer includes profiles of the major self-report dietary assessment instruments, including guidance on the best uses of each instrument; discussion of validation and measurement error generally and with respect to each instrument; guidance for choosing a dietary assessment approach for different research questions; and additional resources, such as a glossary, references, and overviews of specific/important issues in the field. This monograph also describes some future research needs in the field of dietary assessment.

Comparison of Interviewer-Administered and Automated Self-Administered 24-Hour Dietary Recalls in 3 Diverse Integrated Health Systems.

Twenty-four-hour dietary recalls provide high-quality intake data but have been prohibitively expensive for large epidemiologic studies. This study's goal was to assess whether the web-based Automated Self-Administered 24-Hour Recall (ASA24) performs similarly enough to the standard interviewer-administered, Automated Multiple-Pass Method (AMPM) 24-hour dietary recall to be considered a viable alternative. In 2010-2011, 1,081 adults from 3 integrated health systems in Detroit, Michigan; Marshfield, Wisconsin; and Kaiser-Permanente Northern California participated in a field trial. A quota design ensured a diverse sample by sex, age, and race/ethnicity. Each participant was asked to complete 2 recalls and was randomly assigned to 1 of 4 protocols differing by type of recall and administration order. For energy, the mean intakes were 2,425 versus 2,374 kcal for men and 1,876 versus 1,906 kcal for women by AMPM and ASA24, respectively. Of 20 nutrients/food groups analyzed and controlling for false discovery rate, 87% were judged equivalent at the 20% bound. ASA24 was preferred over AMPM by 70% of the respondents. Attrition was lower in the ASA24/AMPM study group than in the AMPM/ASA24 group, and it was lower in the ASA24/ASA24 group than in the AMPM/AMPM group. ASA24 offers the potential to collect high-quality dietary intake information at low cost with less attrition.

How willing are adolescents to record their dietary intake? The mobile food record.

BACKGROUND: Accurately assessing the diets of children and adolescents can be problematic. Use of technologies, such as mobile apps designed to capture food and beverages consumed at eating occasions with images taken using device-embedded cameras, may address many of the barriers to gathering accurate dietary intake data from adolescents. OBJECTIVE: The objectives of this study were to assess the willingness of adolescents to take images of food and beverages at their eating occasions using a novel mobile food record (mFR) and to evaluate the usability of the user confirmation component of the mFR app, referred to as the "review process." METHODS: Mixed methods combining quantitative and qualitative protocols were used in this study. Adolescents (11-15-year olds) attending a summer camp were recruited to participate in the study. First, the participants were asked to take images of foods and beverages consumed as meals and snacks for 2 consecutive days using the mFR app running on an iPhone and the number of images taken was noted. This was followed by focus group sessions to evaluate usability, which was analyzed by content and themes. After using the mFR, a think-aloud method was used to evaluate the usability of the mFR method for reviewing system-identified foods (ie, the review process). A usability questionnaire was administered at the end of all activities. RESULTS: The mFR was accepted by the majority of the 24 boys and 17 girls (n=41) but varied according to gender and eating occasion. Girls were significantly more likely than boys to capture images of their eating occasions (Fisher exact test, P=.03). Participants were more likely to take images of their breakfasts (90%, 36/40) and lunches (90%, 72/80) and least likely to capture afternoon and evening snacks, 54% (43/80) and 40% (32/80), respectively. The major themes from the focus groups with regard to using the mFR were games, rewards, and the need to know more about why they were using the app. Results of the usability questionnaire indicated that including a game component would be important to increase willingness to use the mFR, and a high majority of the participants indicated a willingness to use the mFR for 7 days or more. The image review process was found to be easy to use except for some confusion with overlapping markers on the screen. CONCLUSIONS: The adolescents' experiences with and feedback about the mFR highlighted the importance of increased training, reminders, entertainment (eg, games), and training with practice in using the device to capture complete dietary intake as part of their active lifestyles.

The Dietary Patterns Methods Project: synthesis of findings across cohorts and relevance to dietary guidance.

The Dietary Patterns Methods Project (DPMP) was initiated in 2012 to strengthen research evidence on dietary indices, dietary patterns, and health for upcoming revisions of the Dietary Guidelines for Americans, given that the lack of consistent methodology has impeded development of consistent and reliable conclusions. DPMP investigators developed research questions and a standardized approach to index-based dietary analysis. This article presents a synthesis of findings across the cohorts. Standardized analyses were conducted in the NIH-AARP Diet and Health Study, the Multiethnic Cohort, and the Women's Health Initiative Observational Study (WHI-OS). Healthy Eating Index 2010, Alternative Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean Diet, and Dietary Approaches to Stop Hypertension (DASH) scores were examined across cohorts for correlations between pairs of indices; concordant classifications into index score quintiles; associations with all-cause, cardiovascular disease (CVD), and cancer mortality with the use of Cox proportional hazards models; and dietary intake of foods and nutrients corresponding to index quintiles. Across all cohorts in women and men, there was a high degree of correlation and consistent classifications between index pairs. Higher diet quality (top quintile) was significantly and consistently associated with an 11-28% reduced risk of death due to all causes, CVD, and cancer compared with the lowest quintile, independent of known confounders. This was true for all diet index-mortality associations, with the exception of AHEI-2010 and cancer mortality in WHI-OS women. In all cohorts, survival benefit was greater with a higher-quality diet, and relatively small intake differences distinguished the index quintiles. The reductions in mortality risk started at relatively lower levels of diet quality. Higher scores on each of the indices, signifying higher diet quality, were associated with marked reductions in mortality. Thus, the DPMP findings suggest that all 4 indices capture the essential components of a healthy diet.

Comparison of known food weights with image-based portion-size automated estimation and adolescents' self-reported portion size.

BACKGROUND: Diet is a critical element of diabetes self-management. An emerging area of research is the use of images for dietary records using mobile telephones with embedded cameras. These tools are being designed to reduce user burden and to improve accuracy of portion-size estimation through automation. The objectives of this study were to (1) assess the error of automatically determined portion weights compared to known portion weights of foods and (2) to compare the error between automation and human. METHODS: Adolescents (n = 15) captured images of their eating occasions over a 24 h period. All foods and beverages served were weighed. Adolescents self-reported portion sizes for one meal. Image analysis was used to estimate portion weights. Data analysis compared known weights, automated weights, and self-reported portions. RESULTS: For the 19 foods, the mean ratio of automated weight estimate to known weight ranged from 0.89 to 4.61, and 9 foods were within 0.80 to 1.20. The largest error was for lettuce and the most accurate was strawberry jam. The children were fairly accurate with portion estimates for two foods (sausage links, toast) using one type of estimation aid and two foods (sausage links, scrambled eggs) using another aid. The automated method was fairly accurate for two foods (sausage links, jam); however, the 95% confidence intervals for the automated estimates were consistently narrower than human estimates. CONCLUSIONS: The ability of humans to estimate portion sizes of foods remains a problem and a perceived burden. Errors in automated portion-size estimation can be systematically addressed while minimizing the burden on people. Future applications that take over the burden of these processes may translate to better diabetes self-management.

Novel technologies for assessing dietary intake: evaluating the usability of a mobile telephone food record among adults and adolescents.

BACKGROUND: The development of a mobile telephone food record has the potential to ameliorate much of the burden associated with current methods of dietary assessment. When using the mobile telephone food record, respondents capture an image of their foods and beverages before and after eating. Methods of image analysis and volume estimation allow for automatic identification and volume estimation of foods. To obtain a suitable image, all foods and beverages and a fiducial marker must be included in the image. OBJECTIVE: To evaluate a defined set of skills among adolescents and adults when using the mobile telephone food record to capture images and to compare the perceptions and preferences between adults and adolescents regarding their use of the mobile telephone food record. METHODS: We recruited 135 volunteers (78 adolescents, 57 adults) to use the mobile telephone food record for one or two meals under controlled conditions. Volunteers received instruction for using the mobile telephone food record prior to their first meal, captured images of foods and beverages before and after eating, and participated in a feedback session. We used chi-square for comparisons of the set of skills, preferences, and perceptions between the adults and adolescents, and McNemar test for comparisons within the adolescents and adults. RESULTS: Adults were more likely than adolescents to include all foods and beverages in the before and after images, but both age groups had difficulty including the entire fiducial marker. Compared with adolescents, significantly more adults had to capture more than one image before (38% vs 58%, P = .03) and after (25% vs 50%, P = .008) meal session 1 to obtain a suitable image. Despite being less efficient when using the mobile telephone food record, adults were more likely than adolescents to perceive remembering to capture images as easy (P < .001). CONCLUSIONS: A majority of both age groups were able to follow the defined set of skills; however, adults were less efficient when using the mobile telephone food record. Additional interactive training will likely be necessary for all users to provide extra practice in capturing images before entering a free-living situation. These results will inform age-specific development of the mobile telephone food record that may translate to a more accurate method of dietary assessment.

Adolescents in the United States can identify familiar foods at the time of consumption and when prompted with an image 14 h postprandial, but poorly estimate portions.

OBJECTIVE: To evaluate adolescents' abilities to identify foods and estimate the portion size of foods consumed in order to inform development of the mobile telephone food record (mpFR). DESIGN: Data were collected from two samples of adolescents (11-18 years). Adolescents in sample 1 participated in one lunch (n 63) and fifty-five of the sixty-three adolescents (87 %) returned for breakfast the next morning. Sample 2 volunteers received all meals and snacks for a 24 h period. At mealtime, sample 1 participants were asked to write down the names of the foods. Sample 2 participants identified foods in an image of their meal 10-14 h postprandial. Adolescents in sample 2 also estimated portion sizes of their breakfast foods and snacks. RESULTS: Sample 1 identified thirty of the thirty-eight food items correctly, and of the misidentified foods all were identified within the correct major food group. For sample 2, eleven of the thirteen food items were identified correctly 100 % of the time. Half of the breakfast and snack foods had at least one portion size estimate within 10 % of the true amount using a variety of measurement descriptors. CONCLUSIONS: The results provide evidence that adolescents can correctly identify familiar foods and they can look at an image of their meal and identify the foods in the image up to 14·5 h postprandial. The results of the present study not only inform the development of the mpFR but also provide strong evidence of the use of digital images of eating occasions in research and clinical settings.

Evaluation of the Food and Nutrient Database for Dietary Studies for use with a mobile telephone food record.

The development of a mobile telephone food record (mpFR) in which image analysis and volume estimation data can be indexed with the Food and Nutrient Database for Dietary Studies (FNDDS) has the potential to improve the accuracy of dietary assessment. To validate the mpFR for use with adolescents, a convenience sample of adolescents, aged 11-18 years, was recruited to eat all meals and snacks in a controlled feeding environment over a 24-hour period. Each food item matched a food code in the FNDDS 3.0. The objective of this analysis was to compare the measured energy and protein content of foods to the published values in the FNDDS. Duplicate plates of all meals and snacks were prepared, and samples of 20 foods were individually weighed, homogenized, freeze dried, and analyzed for energy with a bomb calorimeter and for protein with a Dumas nitrogen analyzer. Eleven of the twenty food items had energy values in the FNDDS within ±10% of the measured energy value. The measured energy and protein values from all foods correlated significantly with the energy (r=0.981, P<0.01) and protein (r= 0.911, P<0.01) values in the FNDDS. These results support the use of the FNDDS with the mpFR.

Evidence-based development of a mobile telephone food record.

Mobile telephones with an integrated camera can provide a unique mechanism for collecting dietary information that reduces burden on record-keepers. Objectives for this study were to test whether participant's proficiency with the mobile telephone food record improved after training and repeated use and to measure changes in perceptions regarding use of the mobile telephone food record after training and repeated use. Seventy-eight adolescents (26 males, 52 females) ages 11 to 18 years were recruited to use the mobile telephone food record for one or two meals. Proficiency with the mobile telephone food record was defined as capturing a useful image for image analysis and self-reported ease of use. Positive changes in perceptions regarding use of the mobile telephone food record were assumed to equate to potentially improved proficiency with the mobile telephone food record. Participants received instruction for using the mobile telephone food record prior to their first meal, and captured an image of their meals before and after eating. Following the first meal, participants took part in an interactive session where they received additional training on capturing images in various snacking situations and responded to questions about user preferences. Changes in the participants' abilities to capture useful images and perceptions about the usability of the mobile telephone food record were examined using McNemar, Wilcoxon rank-sum test, and paired t test. After using the mobile telephone food record, the majority of participants (79%) agreed that the software was easy to use. Eleven percent of participants agreed taking images before snacking would be easy. After additional training, the percent increased significantly to 32% (P<0.0001). For taking images after snacking, there was also improvement (21% before training and 43% after; P<0.0001). Adolescents readily adopt new technologies; however, the mobile telephone food record design needs to accommodate the lifestyles of its users to ensure useful images and continuous use. Further, these results suggest that additional training in using a new technology may improve the accuracy among users.