Determinants of consumption-day amounts applicable for the estimation of usual dietary intake with a short 24-h food list

Dietary Intake of Adolescents and Alignment with Recommendations for Healthy and Sustainable Diets: Results of the SI.Menu Study

BACKGROUND

The SI.Menu study offers the latest data on the dietary intake of Slovenian adolescents aged 10 to 17. The purpose of this study is to comprehensively assess their dietary intake (energy and nutrients) and compare their food intakes with dietary recommendations for healthy and sustainable diets.

METHODS

The cross-sectional epidemiological dietary study SI.Menu (March 2017-April 2018) was conducted on a representative sample of Slovenian adolescents aged 10 to 17 years (n = 468) (230 males and 238 females). Data on dietary intake were gathered through two non-consecutive 24 h recalls, in line with the European Food Safety Authority (EFSA) EU Menu methodology. The repeated 24 h Dietary Recall (HDR) and Food Propensity Questionnaire (FPQ) data were combined to determine the usual intakes of nutrients and food groups, using the Multiple Source Method (MSM) program.

RESULTS

Adolescents' diets significantly deviate from dietary recommendations, lacking vegetables, milk and dairy products, nuts and seeds, legumes, and water, while containing excessive meat (especially red meat) and high-sugar foods. This results in insufficient intake of dietary fibre, and nutrients such as vitamin D, folate, and calcium.

CONCLUSIONS

The dietary intake of Slovenian adolescents does not meet healthy and sustainable diet recommendations. This study provides an important insight into the dietary habits of Slovenian adolescents that could be useful for future public health strategies.

A Preliminary Study on a Form of the 24-h Recall That Balances Survey Cost and Accuracy, Based on the NCI Method

The 24-h recall (24HR) is a short-term dietary assessment instrument that is widely used in large-scale nutrition surveys. The number of survey days is critical in the accuracy of estimates. The multiple, repeated collection of 24HRs can yield reliable dietary intakes, whereas that is not always feasible due to staffing, equipment, financial, and temporal constraints. The NCI (National Cancer Institute) method was developed to address this limitation by using only within-person variance to calculate usual dietary intake. However, the performance of different forms of 24HRs based on the NCI method remains unclear. The aim of this study was to explore a form of 24HR based on the NCI method that can balance accuracy and survey cost. A total of 595 subjects completed 7 consecutive 24HRs in each season, for a total of 28 24HRs. The averages of the 28 collection days were defined as the reference value to compare the performance of 24HRs for two consecutive days (C2), three consecutive days (C3), two non-consecutive days (NC2), and three non-consecutive days (NC3) for estimating the dietary intakes of Chinese adults. The equivalence test was used to evaluate whether the estimates of scenarios NC2 and NC3 were equivalent. Additionally, the accuracy of a scenario of NC2 which included a weekend was compared to that of a scenario of NC2 which included two weekdays. All results of the 24HRs in each scenario were corrected by the NCI method. Bias/relative bias and mean bias/mean relative bias were used as measures of precision and accuracy, respectively. The results showed that the precision was similar among the four scenarios, while the accuracy relationship varied among the different dietary components. In general, scenario NC3 was the most accurate, followed by scenario NC2, which was close to the former. The form using non-consecutive days was more accurate than that using consecutive days, and the main factor affecting the accuracy of the 24HRs was the continuity between multiple survey days rather than the number of days. The means and major percentiles of energy, nutrients, and frequently consumed food in scenarios NC2 and NC3 were functionally identical. The accuracy of the scenario of NC2 which included a weekend was higher than that of scenario NC2, which consisted of only weekdays. The above results indicated that the adoption of two, non-consecutive 24HRs consisting of a weekend and a weekday to collect dietary data prior to correction by the NCI method, is a feasible approach to balancing survey costs and accuracy in large-scale nutrition surveys.

Comparison of the 24 h Dietary Recall of Two Consecutive Days, Two Non-Consecutive Days, Three Consecutive Days, and Three Non-Consecutive Days for Estimating Dietary Intake of Chinese Adult

The specific forms of 24 h dietary recall used by national nutrition surveys differ, such as two non-consecutive days and three consecutive days. However, it is unclear which form of 24 h dietary recall is more accurate in the Chinese population. The purpose of this study was to compare the performance of 24 h recalls on two consecutive days (C2), three consecutive days (C3), two non-consecutive days (NC2), and three non-consecutive days (NC3) in estimating Chinese adult dietary intake. A total of 595 participants completed more than twenty-three 24 h recalls. The average of all completed 24 h recalls of each subject was defined as the individual’s true dietary intake. The dietary intake in the four scenarios of 24 h recalls was calculated using the within-person mean (WPM) method and National Cancer Institute (NCI) method and compared with the true values. Equivalent testing was used to evaluate whether scenarios NC2 and C3 were equivalent. Bias and mean bias were used as a measure of precision and accuracy, respectively. For the WPM method, the precision between the four scenarios was similar. For mean, the accuracy between the four scenarios was similar, yielding estimates that were close to the true intakes. However, for percentiles, the accuracy in descending order was scenario NC3, C3, NC2, and C2. Furthermore, the difference between two and three days was greater than that between consecutive and non-consecutive days. In most case, the distribution of dietary intakes calculated from scenarios NC2 and C3 was equivalent with equivalence margins of 5% (p < 0.05). Usually, the NCI method was significantly more accurate than the WPM method. We concluded that three non-consecutive 24 h recalls relative to three consecutive days increases accuracy. Two non-consecutive days can be substituted to some extent for three consecutive days. The new form of 24 h recall needs to be used with caution when applied practically in the China nutrition surveys. Furthermore, using the NCI method to calculate dietary intake from 24 h recall may be a way to reduce costs and increase accuracy.

Validation of the MSM and NCI Method for Estimating the Usual Intake of Nutrients and Food According to Four Seasons of Seven Consecutive Daily 24 Hour Dietary Recalls in Chinese Adults

The Multiple Source Method (MSM) and the National Cancer Institute (NCI) method are used to estimate usual dietary intake from short-term dietary assessment instruments, such as 24 hour dietary recall (24-HRs). However, their performance has not been validated in the Chinese population via nutrition surveys. To validate the accuracy of the MSM and NCI method in estimating usual dietary intake in the Chinese population, 752 individuals from northern and southern China answered four seasons of seven consecutive 24-HRs (one for each season). The true usual dietary intake was considered as the average of the 28 collection days of dietary component intake. Using data sets with consecutive 3 collection days, the usual intakes of the selected dietary components were estimated by MSM, NCI and the within-person mean of three 24-HRs (3 day method). These estimates were compared with the true usual intake at the group and individual level. At the group level, the MSM and NCI method performed similarly, yielding estimates closer to the true usual intake than 3 day method. The percentage differences of the estimates for dietary components not consumed daily from the MSM and NCI method were larger than for the dietary components consumed daily. However, the larger percentage differences were observed in the tail of the usual intake distribution. In general, dietary components with larger variance ratios had greater percentage differences. At the individual level, for overall seasons and dietary components, the biases of individual usual intake did agree for MSM and NCI method, whereas NCI method estimates were closer to true intakes than for the MSM and 3 day method. Similar results were observed in the relative biases of dietary components consumed daily. As with the group level, there was less percentage difference in dietary components consumed daily. Both the MSM and NCI method can be used to estimate usual intake in Chinese populations and are closer to the true usual intake than the traditional mean method, at both group and individual levels.

Usual Dietary Intake Estimation Based on a Combination of Repeated 24-H Food Lists and a Food Frequency Questionnaire in the KORA FF4 Cross-Sectional Study

Background: Estimation of usual dietary intake poses a challenge in epidemiological studies. We applied a blended approach that combines the strengths provided by repeated 24-h food lists (24HFLs) and a food frequency questionnaire (FFQ). Methods: At least two web-based 24HFLs and one FFQ were completed by 821 participants in the KORA FF4 study. Consumption probabilities were estimated using logistic mixed models, adjusting for covariates and the FFQ data on consumption frequency. Intake amount of a consumed food item was predicted for each participant based on the results of the second Bavarian Food Consumption Survey (BVS II). By combining consumption probability and estimated consumption amount, the usual food intake for each participant was estimated. These results were compared to results obtained without considering FFQ information for consumption probability estimation, as well as to conventional FFQ data. Results: The results of the blended approach for food group intake were often higher than the FFQ-based results. Intraclass correlation coefficients between both methods ranged between 0.21 and 0.86. Comparison of both methods resulted in weighted kappa values based on quintiles ranging from fair (0.34) to excellent agreement (0.84). Omission of FFQ information in the consumption probability models distinctly affected the results at the group level, though individual intake data were slightly affected, for the most part. Conclusions: Usual dietary intake data based on the blended approach differs from the FFQ-based results both in absolute terms and in classification according to quintiles. The application of the blended approach has been demonstrated as a possible tool in nutritional epidemiology, as a comparison with published studies showed that the blended approach yields reasonable estimates. The inclusion of the FFQ information is valuable especially with regard to irregularly consumed foods. A validation study including biomarkers of dietary intake is warranted.

Design and characterization of dietary assessment in the German National Cohort

BACKGROUND/OBJECTIVES

The aim of the study was to describe a novel dietary assessment strategy based on two instruments complemented by information from an external population applied to estimate usual food intake in the large-scale multicenter German National Cohort (GNC). As proof of concept, we applied the assessment strategy to data from a pretest study (2012-2013) to assess the feasibility of the novel assessment strategy.

SUBJECTS/METHODS

First, the consumption probability for each individual was modeled using three 24 h food lists (24h-FLs) and frequencies from one food frequency questionnaire (FFQ). Second, daily consumed food amounts were estimated from the representative German National Nutrition Survey II (NVS II) taking the characteristics of the participants into account. Usual food intake was estimated using the product of consumption probability and amounts.

RESULTS

We estimated usual intake of 41 food groups in 318 men and 377 women. The participation proportion was 100, 84.4, and 68.5% for the first, second, and third 24h-FL, respectively. We observed no associations between the probability of participating and lifestyle factors. The estimated distributions of usual food intakes were plausible and total energy was estimated to be 2707 kcal/day for men and 2103 kcal/day for women. The estimated consumption frequencies did not differ substantially between men and women with only few exceptions. The differences in energy intake between men and women were mostly due to differences in estimated daily amounts.

CONCLUSIONS

The combination of repeated 24h-FLs, a FFQ, and consumption-day amounts from a reference population represents a user-friendly dietary assessment approach having generated plausible, but not yet validated, food intake values in the pretest study.

New approaches in assessing food intake in epidemiology

PURPOSE OF REVIEW

A promising direction for improving dietary intake measurement in epidemiologic studies is the combination of short-term and long-term dietary assessment methods using statistical methods. Thereby, web-based instruments are particularly interesting as their application offers several potential advantages such as self-administration and a shorter completion time. The objective of this review is to provide an overview of new web-based short-term instruments and to describe their features.

RECENT FINDINGS

A number of web-based short-term dietary assessment tools for application in different countries and age-groups have been developed so far. Particular attention should be paid to the underlying database and the search function of the tool. Moreover, web-based instruments can improve the estimation of portion sizes by offering several options to the user.

SUMMARY

Web-based dietary assessment methods are associated with lower costs and reduced burden for participants and researchers, and show a comparable validity with traditional instruments. When there is a need for a web-based tool researcher should consider the adaptation of existing tools rather than developing new instruments. The combination of short-term and long-term instruments seems more feasible with the use of new technology.

Estimating Usual Intake in the 2nd Bavarian Food Consumption Survey: Comparison of the Results Derived by the National Cancer Institute Method and a Basic Individual Means Approach

BACKGROUND

The valid estimation of the usual dietary intake remains a challenge till date. We applied the method suggested by the National Cancer Institute (NCI) to data from the 2nd Bavarian Food Consumption Survey (BVS II) and compared it to an individual means approach.

METHODS

Within the cross-sectional BVS II, 1,050 Bavarian residents aged 13-80 years participated in a personal interview and completed three 24-h dietary recalls by telephone interview. For the 13 main food groups and 23 subgroups the usual intake was calculated by (1) an individual means approach and (2) by the NCI method.

RESULTS

The distributions derived by the individual means approach are wider than those derived from the NCI approach. For a majority of food groups and subgroups, the proportion of participants who meet the dietary recommendations published by the German Nutrition Society is higher when the NCI approach is applied. The proportions of participants above or below recommended amounts differ greatly for "meat and meat products" and "cheese."

CONCLUSION

The mean intake at the groups level can easily be derived from the individual means approach. Since only the NCI method accounts for intra-personal variation, this method provides more valid intake estimates at the individual level and should be applied when, for example, individual intakes are compared with dietary recommendations.

Innovative approaches to estimate individual usual dietary intake in large-scale epidemiological studies

Valid estimation of usual dietary intake in epidemiological studies is a topic of present interest. The aim of the present paper is to review recent literature on innovative approaches focussing on: (1) the requirements to assess usual intake and (2) the application in large-scale settings. Recently, a number of technology-based self-administered tools have been developed, including short-term instruments such as web-based 24-h recalls, mobile food records or simple closed-ended questionnaires that assess the food intake of the previous 24 h. Due to their advantages in terms of feasibility and cost-effectiveness these tools may be superior to conventional assessment methods in large-scale settings. New statistical methods have been developed to combine dietary information from repeated 24-h dietary recalls and FFQ. Conceptually, these statistical methods presume that the usual food intake of a subject equals the probability of consuming a food on a given day, multiplied by the average amount of intake of that food on a typical consumption day. Repeated 24-h recalls from the same individual provide information on consumption probability and amount. In addition, the FFQ can add information on intake frequency of rarely consumed foods. It has been suggested that this combined approach may provide high-quality dietary information. A promising direction for estimation of usual intake in large-scale settings is the integration of both statistical methods and new technologies. Studies are warranted to assess the validity of estimated usual intake in comparison with biomarkers.