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Background: Diet quality indexes, including the Healthy Eating Index, assess diets based on usual dietary intakes and a scoring function. Nearly all diet quality indexes use scoring functions that have floors and ceilings, thereby truncating the scores and losing information about intakes outside the scoring range. This score truncation has 2 important impacts: 1) the index does not reflect all intakes; and 2) the assumption that measurement error in intake reporting has a neutral impact on the diet quality score cannot be upheld.Objectives: Our main objective was to devise new diet quality scoring functions that eliminate truncation and its attendant problems.Methods: Seven desirable properties of a new scoring function were identified: 1) avoid truncations in component scoring to prevent information loss and to provide scoring sensitivity in the currently truncated regions; 2) reduce dependency on the accuracy of dietary standards; 3) minimize measurement error bias and subsequent misclassification; 4) relate plausibly to biological processes; 5) possess desirable mathematical and statistical properties; 6) have simple representations that are easy to calculate and add minimum artifacts of their own; and 7) otherwise closely mimic existing scoring functions.Results: The recommended replacement for piecewise-linear scoring is a family of scoring functions based on exponentials. For components where higher intakes are better, the function is a single exponential. For components where lower intakes are better, the function is a concave-convex mirrored pair of exponentials. The proposed exponential scoring functions have all 7 desired properties.Conclusions: The proposed exponential scoring functions will improve the usefulness of dietary scoring indexes by eliminating truncations. Compared to existing scoring functions, the use of exponentials makes the scores more inclusive of very high and very low intakes, reduces measurement error bias, and is less sensitive to the exact placement of the scoring standards. [ABSTRACT FROM AUTHOR]

Background: The nitrate content of foods and water is highly variable, which has implications for the compilation of foodcomposition databases and assessment of dietary nitrate intake. Objective: A systematic review was conducted to ascertain the dietary assessment methods used and to provide estimates of daily nitrate intake in humans. Design: Relevant articles were identified by a systematic search of 3 electronic databases (PubMed,Web of Science, and Embase) from inception until February 2018. Observational studies conducted in adult populations and reporting information on dietary assessment methods and daily nitrate intake were included. Ecological analyses were conducted to explore the association of nitrate intake with indexes of economic development [Gross Domestic Product (GDP) and KOF Index of Globalization]. Results: A total of 55 articles were included. Forty-two studies investigated associations between nitrate intake and disease risk; 36 (87%) of these studies examined the association between nitrate intake and cancer risk, whereas only 6 studies explored the association of nitrate intake with the risk of diabetes, glaucoma, kidney failure, hypertension, and atherosclerotic vascular disease. The majority of studies used food-frequency questionnaires to assess nitrate intake (n = 43). The median daily nitrate intakes in healthy and patient populations were 108 and 110 mg/d, respectively. We found a significant inverse correlation of nitrate intake with GDP (r=−0.46, P < 0.001) and KOF index (r=−0.31, P = 0.002). Conclusions: The median estimated daily nitrate intakes by healthy and patient populations were similar, and these values were belowthe safe upper intake of daily intake (3.7 mg nitrate ion/kg body weight). However, there is considerable heterogeneity in the application of food-composition tables, which may have implications for the accuracy of estimated daily nitrate intake. The association between nitrate intake and risk of cardiometabolic diseases needs further investigation. [ABSTRACT FROM AUTHOR]

Background: Underreporting of energy intake is associated with self-reported diet measures and appears to be selective according to personal characteristics. Doubly labeled water is an unbiased reference biomarker for energy intake that may be used to assess under-reporting. Objective: Our objective was to determine which factors are associated with underreporting of energy intake on food-frequency questionnaires (FFQs) and 24-h dietary recalls (24HRs). Design: The study participants were 484 men and women aged 40-69 y who resided in Montgomery County, MD. Using the doubly labeled water method to measure total energy expenditure, we considered numerous psychosocial, lifestyle, and sociodemographic factors in multiple logistic regression models for prediction of the probability of underreporting on the FFQ and 24HR. Results: In the FFQ models, fear of negative evaluation, weight-loss history, and percentage of energy from fat were the best predictors of underreporting in women (R2=0.09); body mass index, comparison of activity level with that of others of the same sex and age, and eating frequency were the best predictors in men (R2=0.10). In the 24HR models, social desirability, fear of negative evaluation, body mass index, percentage of energy from fat, usual activity, and variability in number of meals per day were the best predictors of underreporting in women (R2=0.22); social desirability, dietary restraint, body mass index, eating frequency, dieting history, and education were the best predictors in men (R2 = 0.25). Conclusion: Although the final models were significantly related to underreporting on both the FFQ and the 24HR, the amount of variation explained by these models was relatively low, especially for the FFQ. [ABSTRACT FROM AUTHOR]

A list of research priorities related to dietary assessment methodology is presented. The priorities are based on a consensus of opinion by a multidisciplinary international group of experts who participated in the First International Conference on Dietary Assessment Methods. These experts included researchers in dietary assessment methodology, major users of dietary assessment methods, and policymakers involved in setting food and nutrition policies. The list of priorities may be used as a guide for planning future research in dietary assessment methods, for prioritizing the allocation of available research resources, and for planning subsequent conferences. A list of recommendations related to dietary assessment methodology is also presented. Procedures used by the conference planners to select the experts are described, and the need for developing objective criteria for ranking priorities is discussed. An ongoing function of the conference series will be to continue the process of revising the priorities and recommendations to reflect progress made and newly identified needs in dietary assessment methodology. [ABSTRACT FROM AUTHOR]

When collecting dietary data on children, confidence about responses is required. Children exist in multienvironments in their everyday lives, eg, the personal, school, home, peer, medical cane, media, food industry, and fast-food facility environments. These macroenvironments influence the format and type of data-collection methods used to interview today's youth. Researchers should identify the influence of each environment on the child's eating pattern and nutrient intake, explore the pros and cons of various data-collection methods amid these environments, and determine unresolved methodological issues to stimulate future research. Standardized protocols for interviewing children, exclusion criteria for surrogate responses, and currency of nutrient data for new food products available to children are needed. Redefining our methods by understanding the macroenvironments of youth can create a dietary methodology for the 21st century-an evolutionary method that builds on past research and incorporates current technology and societal changes. [ABSTRACT FROM AUTHOR]

The rationale for establishing an international conference series on dietary assessment methods is based on the needs expressed by numerous national and international organizations for better methods of collecting and analyzing dietary data. Dietary assessment is essential for investigating diet-health relationships, formulating policies to reduce health risks, predicting the adequacy of the food supply, and monitoring trends in food use, exposure to contaminants, and compliance with dietary guidelines. The conference rationale is discussed with respect to 1) the need for improved methods to enhance our understanding of diet-health relationships, 2) the need for better methods to facilitate development and monitoring of nutrition-related health objectives, and 3) the importance of international participation. Improved methods for assessing food intakes will enhance our understanding of the role of diet in the etiology and prevention of disease and will facilitate the development of nutrition policy and programs leading to improved health worldwide. [ABSTRACT FROM AUTHOR]