National Nutrition Surveys Applying Dietary Records or 24-h Dietary Recalls with Questionnaires: A Scoping Review

Development of an accurate and efficient dietary method is required for national nutrition surveys. Some countries conduct dietary surveys and combine 24-h dietary records or 24-h dietary recalls with dietary questionnaires. This scoping review aimed to summarize studies that used results from national surveys that combined detailed dietary surveys (dietary records or 24-h dietary recall) and dietary questionnaires and identify the purpose of combining the two methods. The PubMed database and manual searches were used for the literature review. We extracted 58 articles from 16 national nutrition surveys from 14 countries. Most studies used 24-h dietary recall for detailed dietary surveys and the food frequency questionnaire (FFQ) or food propensity questionnaire (FPQ) for questionnaire surveys. Among 37 studies from eight countries, the purpose of combining the two dietary survey methods was to estimate energy and nutrient intakes from detailed dietary surveys and habitual food intake from questionnaires. These findings are useful as a reference when introducing new dietary survey methods in future national nutrition surveys.


Introduction
National nutrition surveys are conducted worldwide to assess people's health status and nutritional intake [1,2].Results from many national dietary surveys are used to monitor the population's health and nutritional status.Furthermore, they are utilized to develop national nutritional policies and formulate dietary guidelines [3][4][5][6][7].
Dietary survey methods applied in national surveys are similar to those used in various epidemiological studies, such as dietary records, 24-h dietary recalls, food frequency questionnaires (FFQs), and dietary history methods [8].Some national surveys that conduct dietary surveys combine 24-h dietary recall and FFQs or the food propensity questionnaire (FPQ) (the National Health and Nutrition Examination Survey (NHEANS) from 1999 to 2006 in the United States [9], the Korea National Health and Nutrition Examination Survey (KNHANES) from 2007 to 2018 [10], and the Slovenian national dietary survey (SI.Menu 2017/18) [11]).Detailed dietary surveys, such as dietary records and 24-h dietary recall, can estimate participants' nutrient intake.However, these methods impose a heavy burden on the participants and investigators [8].Conversely, although it is more difficult to estimate the absolute value of nutrient intake via FFQs than through detailed surveys, it can be First, the titles and abstracts of the identified articles underwent screening in accordance with the eligibility criteria (E.O., M.N., and F.H.).Second, full texts were assessed for eligibility, and articles for review were extracted (E.O., M.N., and F.H.).Additionally, potentially relevant articles were manually searched and additional articles were identified.All of the articles were screened or independently reviewed by at least two researchers.Any discrepancies were discussed and resolved through consensus or with the involvement of another reviewer, if necessary (H.T. and S.S.).

Data Extraction
Data were extracted and summarized into a standardized tabular format (Excel sheet) by two independent reviewers.The extracted information included (1) authors, (2) publication year, (3) country, (4) survey name, (5) study year, (6) population and sample size, (7) aims, (8) detailed dietary survey method (dietary record or 24-h dietary recall), (9) dietary questionnaire, (10) how to use the dietary survey results from the detailed dietary method and dietary questionnaire, and (11) limitations of the dietary survey methods (if applicable).

Study Selection
A total of 469 articles were extracted.Figure 1 shows the flowchart of the literature selection process.After 391 articles that did not meet the inclusion criteria were excluded during the initial title and abstract screening, 78 articles underwent full screening.In the full-text screening, 21 articles were excluded, including studies that did not combine detailed dietary survey methods and questionnaires, studies that did not conduct the two dietary survey methods for the same individuals, studies that did not use the data from national surveys, and studies employing a survey methodology (FFQ development not examining the validation of the FFQ), based on the exclusion criteria.Furthermore, one article was identified via a manual search [14].A total of 58 articles were included.

Study Selection
A total of 469 articles were extracted.Figure 1 shows the flowchart of the literature selection process.After 391 articles that did not meet the inclusion criteria were excluded during the initial title and abstract screening, 78 articles underwent full screening.In the full-text screening, 21 articles were excluded, including studies that did not combine detailed dietary survey methods and questionnaires, studies that did not conduct the two dietary survey methods for the same individuals, studies that did not use the data from national surveys, and studies employing a survey methodology (FFQ development not examining the validation of the FFQ), based on the exclusion criteria.Furthermore, one article was identified via a manual search [14].A total of 58 articles were included.
Misreporting in dietary intake and energy and macronutrient intakes was possible due to the use of a single 24-h recall that may not represent usual intake.

FFQ
The distribution of habitual food consumption was estimated to combine 24-h recall and FFQ data based on statistical models accounting for within-subject variation.
The difference between habitual consumption and recommendations may be due to under-reporting of food intake.

Discussion
This scoping review summarized 58 studies that used results from national surveys that combined detailed dietary surveys, such as dietary records or 24-h dietary recall, and questionnaires.We found 16 nutritional surveys in 14 countries that used a detailed dietary survey combined with a questionnaire.Most studies used the 24-h dietary recall and the FFQ or FPQ as a detailed dietary survey and questionnaire survey, respectively.More  (3) to compare the results of the detailed dietary survey to verify the validity of the questionnaire survey [51,62,64,70,71]; (4) to evaluate the intake status of infrequently consumed foods from the questionnaire survey [25,52,53,60,68]; and (5) to compare intakes of energy, nutrients, and foods estimated from the detailed dietary survey and questionnaire survey [16,39,59,61].

Discussion
This scoping review summarized 58 studies that used results from national surveys that combined detailed dietary surveys, such as dietary records or 24-h dietary recall, and questionnaires.We found 16 nutritional surveys in 14 countries that used a detailed dietary survey combined with a questionnaire.Most studies used the 24-h dietary recall and the FFQ or FPQ as a detailed dietary survey and questionnaire survey, respectively.More than half estimated energy and nutrient intakes from the detailed dietary surveys and evaluated habitual food intake from the questionnaire.
Although dietary records or 24-h dietary recall could estimate food, energy, and nutrient intake from information regarding the foods consumed on the survey day, their use in long-term surveys was difficult owing to the heavy burden on the participants and investigators [8].The included studies reporting that a single day of dietary recall could not assess habitual intake, which was a limitation of the dietary survey [14, 21,23,28,30,31,35,45,47,63].Conversely, surveys that used questionnaires, such as the FFQ, were limited in the number of foods to be investigated; however, it was possible to evaluate participants' habitual food intake [8].In addition, in some studies, questionnaires captured the frequency of consumption of foods that were not frequently consumed and that did not emerge in detailed dietary surveys over a short period of time [25,52,53,60,68].The FFQ is also useful for assessing food safety and exposure to chemical substances and environmental pollutants, which are important for food sanitation administration.The KiESEL study, eligible for young children in Germany, was conducted to estimate the exposure to substances in food, such as contaminants, pesticides, or microbial risks, as required for health assessment [60].Since detailed dietary and questionnaire surveys had different strengths and weaknesses, many included studies were used to compensate for the disadvantages of each dietary survey method and take advantage of their benefits.
To use both dietary methods, it may be necessary to devise ways to reduce the burden on the participants and survey staff.The introduction of a 24-h dietary recall system (such as Intake24 in the United Kingdom [72] or the GloboDiet software adapted to each country in European countries and Korea [73]) that allows participants to enter their dietary intake on a web-based basis and automatically calculate nutrient and food intakes based on the input results could be beneficial.Among the included studies, Riksmaten assessed dietary intake in Sweden via a web-based food record where participants entered their own dietary information [52,53].Another method to reduce the burden was to determine the calibration coefficients from a regression model and compare the nutrient intake estimated from the FFQ with the intake calculated more accurately from a 24-h dietary recall [74].Bassett et al. [74] conducted a study using data from a follow-up of the Melbourne Collaborative Cohort Study in Australia.A method to assess population nutrient intake via calibration coefficients would reduce the number of participants for the 24-h dietary recall.Furthermore, many participants may only need to answer the FFQ.However, our review did not include articles that determined the calibration factors from two dietary survey methods.Examining ways to determine the correction coefficients from the two dietary survey methods in national surveys worldwide is necessary.
National nutrition surveys are important to conduct without interruption, as they monitor the health and nutritional status of the population [1,2] and serve as the basis for national nutrition policy and dietary guidelines [3][4][5][6][7].Although the same dietary survey methods should be used for continuous assessment, new survey methods should also be considered in light of current trends and global conditions, such as the COVID-19 pandemic.In countries that use only one survey method, conducting the FFQ or FPQ, including web-based versions, could be considered for participants with a largeenough sample size, and then the 24-h dietary recall could be implemented for some of the participants.As our results show, the values estimated from the 24-h dietary survey can be used to adjust energy, nutrient, and food intakes obtained from the FFQ by using the two survey methods together [24,33,50,54,55,66].However, the skills of the investigators are critical to conducting a face-to-face survey, such as the 24-h dietary recall or dietary record.There is a need to train skilled nutritionists and provide a certain training period at the implementing agency or other institutions in a systematic manner to improve the accuracy and standardization of the survey methodology, as is carried out in several countries [75][76][77].Moreover, considering that the 24-h recall method may have difficulty estimating seasoning intake, one might contemplate using the dietary record method to assess seasoning intake [78].In addition, to accurately assess nutrient intake, the questionnaire survey should include items related to the use of dietary supplements as well as the frequency of food intake [47,55].If a more accurate measurement of nutrient intake is desired, it may be worth considering the introduction of bioindicators that do not rely on participants' memory.Dietary survey methods in national surveys need to be consider based on the national characteristics, dietary habits, dietary culture, and the feasibility of the survey.
The main strength of this scoping review was that we extracted the purposes of conducting a dietary record or 24-h dietary recall combined with a questionnaire survey via results from national surveys, following scoping review guidelines.We suggested improvements that are needed when employing both 24-h dietary recalls and questionnaires, taking advantage of the strengths and compensating for the weaknesses of each survey method.The results will be useful for national nutrition surveys in countries worldwide and for examining new dietary survey methods consistent with the changing times.However, this scoping review has several limitations.First, there may have been other national surveys that combined the two dietary survey methods that were not included.Some national surveys combined 24-h dietary recall or dietary records and the FFQ; however, they were not extracted from the search.These include the Chinese National Nutrition and Health Surveillance (CNNHS) from 2010 to 2013 [79], the Third Individual and National Food Consumption Survey (INCA3) from 2014 to 2015 in France [80], and the National FinHealth Study in 2017 in Finland [6].Regarding these three national surveys [6,79,80], we searched the original articles that used the data from the survey results.However, these studies used the results of only one dietary survey method.Second, articles that used the results of only one of the two dietary survey methods (either dietary record or 24-h dietary recall and questionnaire) conducted simultaneously on the participants were not included.Therefore, the results based on combining the two dietary survey methods may have been biased.Finally, although we used various search terms and manual searches, we may not have captured all relevant articles.In addition, we used only one database and limited the literature search to the English language.

Conclusions
This scoping review identified the purpose of combining a detailed dietary survey of dietary record or 24-h dietary recall with a questionnaire via results from national surveys.Most studies used 24-h dietary recall for detailed dietary surveys and the FFQ or FPQ for questionnaire surveys.More than half of the included studies estimated nutrient intake from the detailed dietary surveys and evaluated habitual food intake from questionnaires.Our results are useful as a reference for introducing new dietary survey methods into future national nutrition surveys.

Figure 1 .
Figure 1.Flowchart of the selection process.

Figure 1 .
Figure 1.Flowchart of the selection process.

Figure 2 .
Figure 2. Breakdown of the detailed dietary surveys.

Figure 3 .
Figure 3. Breakdown of the dietary questionnaire surveys.

3. 4 .
Purpose of Combined Detailed Dietary Survey of Dietary Record or 24-h Dietary Recall and Questionnaire

Figure 4 .
Figure 4.The number of articles covering each main purpose of conducting a dietary record or 24h dietary recall combined with a questionnaire: (1) to estimate the intake of energy, nutrients, and foods or calculate the dietary scores from the results of the detailed dietary survey and evaluate habitual foods intake frequency and intake/non-intake from a questionnaire survey [14,15,17- 23,26-32,34-38,40-49,56-58,63,65,69];(2) to use the results of the questionnaire survey to complement the intake of energy, nutrients, and foods obtained from the results of detailed dietary surveys[24,33,50,54,55,66]; (3) to compare the results of the detailed dietary survey to verify the validity of the questionnaire survey[51,62,64,70,71]; (4) to evaluate the intake status of infrequently consumed foods from the questionnaire survey[25,52,53,60,68]; and (5) to compare intakes of energy, nutrients, and foods estimated from the detailed dietary survey and questionnaire survey[16,39,59,61].

Table 1 .
Characteristics of the included studies.