Best Practices for Conducting and Interpreting Studies to Validate Self-Report Dietary Assessment Methods

Abstract

Careful consideration of the validity and reliability of methods intended to assess dietary intake is central to the robustness of nutrition research. A dietary assessment method with high validity is capable of providing useful measurement for a given purpose and context. More specifically, a method with high validity is well grounded in theory; its performance is consistent with that theory; and it is precise, dependable, and accurate within specified performance standards. Assessing the extent to which dietary assessment methods possess these characteristics can be difficult due to the complexity of dietary intake, as well as difficulties capturing true intake. We identified challenges and best practices related to the validation of self-report dietary assessment methods. The term validation is used to encompass various dimensions that must be assessed and considered to determine whether a given method is suitable for a specific purpose. Evidence on the varied concepts of validity and reliability should be interpreted in combination to inform judgments about the suitability of a method for a specified purpose. Self-report methods are the focus because they are used in most studies seeking to measure dietary intake. Biomarkers are important reference measures to validate self-report methods and are also discussed. A checklist is proposed to contribute to strengthening the literature on the validation of dietary assessment methods and ultimately, the nutrition literature more broadly.

Food Liking-Based Diet Quality Indexes (DQI) Generated by Conceptual and Machine Learning Explained Variability in Cardiometabolic Risk Factors in Young Adults

“…Another important consideration of diet quality indexes is the scoring and weighting of the individual components, particularly in the examining of associations with cardiovascular disease risk [15]. The Healthy Eating Index scoring is complex, with significant dietary analysis to derive food group scores representing the whole diet, determining portion equivalents adjusted for total energy intakes, and weighting according to the Dietary Guidelines as the relevant standard [18]. In comparison, the scoring of the theoretical, liking-based diet quality index is analytically simple-averaging within the food and beverage groups, weighting, and averaging into the index, while the hybrid, liking-based diet quality index requires a more sophisticated analysis to derive food and beverage group weights based on the associations with the cardiometabolic risk factor scores.…”

“…Usually, diet quality indexes are derived from self-reported measures such as 24-h recalls, food records/diaries, or food frequency questionnaires (FFQ). It is difficult to accurately measure usual intake, including total energy intake [18]. The measures may only capture intake on the short-term (e.g., 24-h recall), missing day-to-day variation in food and energy intakes.…”

Validation of Vitamin D-Specific Food Frequency Questionnaire against Food Records for Qatari Women

“…Before a specific dietary assessment tool for collecting the habitual intake of population is used, it must be validated against a reference standard. Validation is a process of verifying whether a certain type of assessment method would be useful as a measure or indicator for providing useful analytical measurements for a specific purpose and context [21]. FFQs are commonly validated against food records (FR) [19,20,22].…”

Food frequency questionnaire assessing traditional food consumption in Dene/Métis communities, Northwest Territories, Canada

“…The survey was not validated by retesting the same group of participants. However, it is worth noting that Kirkpatrick et al [41] suggested that "inferences should be nuanced, recognizing that constructs such as validity and reliability operate on continuums from low to high, and degrees in between maybe appropriate depending on the research objective." The main purpose of the larger project is to assess contaminant exposure.…”