Comparison of weighed food record procedures for the reference methods in two validation studies of food frequency questionnaires

Background: Although open-ended dietary assessment methods, such as weighed food records (WFRs), are generally considered to be comparable, differences between procedures may influence outcome when WFRs are conducted independently. In this paper, we assess the procedures of WFRs in two studies to describe their dietary assessment procedures and compare the subsequent outcomes. Methods: WFRs of 12 days (3 days for four seasons) were conducted as reference methods for intake data, in accordance with the study protocol, among a subsample of participants of two large cohort studies. We compared the WFR procedures descriptively. We also compared some dietary intake variables, such as the frequency of foods and dishes and contributing foods, to determine whether there were differences in the portion size distribution and intra- and inter-individual variation in nutrient intakes caused by the difference in procedures. Results: General procedures of the dietary records were conducted in accordance with the National Health and Nutrition Survey and were the same for both studies. Differences were seen in 1) selection of multiple days (non-consecutive days versus consecutive days); and 2) survey sheet recording method (individual versus family participation). However, the foods contributing to intake of energy and selected nutrients, the portion size distribution, and intra- and inter-individual variation in nutrient intakes were similar between the two studies. Conclusion: Our comparison of WFR procedures in two independent studies revealed several differences. Notwithstanding these procedural differences, however, the subsequent outcomes were similar

Online dietary intake estimation : Reproducibility and validity of the Food4Me food frequency questionnaire against a 4-day weighed food record

©Rosalind Fallaize, Hannah Forster, Anna L Macready, Marianne C Walsh, John C Mathers, Lorraine Brennan, Eileen R Gibney, Michael J Gibney, Julie A Lovegrove. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 11.08.2014. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.Background: Advances in nutritional assessment are continuing to embrace developments in computer technology. The online Food4Me food frequency questionnaire (FFQ) was created as an electronic system for the collection of nutrient intake data. To ensure its accuracy in assessing both nutrient and food group intake, further validation against data obtained using a reliable, but independent, instrument and assessment of its reproducibility are required. Objective: The aim was to assess the reproducibility and validity of the Food4Me FFQ against a 4-day weighed food record (WFR). Methods: Reproducibility of the Food4Me FFQ was assessed using test-retest methodology by asking participants to complete the FFQ on 2 occasions 4 weeks apart. To assess the validity of the Food4Me FFQ against the 4-day WFR, half the participants were also asked to complete a 4-day WFR 1 week after the first administration of the Food4Me FFQ. Level of agreement between nutrient and food group intakes estimated by the repeated Food4Me FFQ and the Food4Me FFQ and 4-day WFR were evaluated using Bland-Altman methodology and classification into quartiles of daily intake. Crude unadjusted correlation coefficients were also calculated for nutrient and food group intakes. Results: In total, 100 people participated in the assessment of reproducibility (mean age 32, SD 12 years), and 49 of these (mean age 27, SD 8 years) also took part in the assessment of validity. Crude unadjusted correlations for repeated Food4Me FFQ ranged from .65 (vitamin D) to .90 (alcohol). The mean cross-classification into "exact agreement plus adjacent" was 92% for both nutrient and food group intakes, and Bland-Altman plots showed good agreement for energy-adjusted macronutrient intakes. Agreement between the Food4Me FFQ and 4-day WFR varied, with crude unadjusted correlations ranging from .23 (vitamin D) to .65 (protein, % total energy) for nutrient intakes and .11 (soups, sauces and miscellaneous foods) to .73 (yogurts) for food group intake. The mean cross-classification into "exact agreement plus adjacent" was 80% and 78% for nutrient and food group intake, respectively. There were no significant differences between energy intakes estimated using the Food4Me FFQ and 4-day WFR, and Bland-Altman plots showed good agreement for both energy and energy-controlled nutrient intakes. Conclusions: The results demonstrate that the online Food4Me FFQ is reproducible for assessing nutrient and food group intake and has moderate agreement with the 4-day WFR for assessing energy and energy-adjusted nutrient intakes. The Food4Me FFQ is a suitable online tool for assessing dietary intake in healthy adults.Peer reviewedFinal Published versio

Determining the relative validity and reproducibility of a complementary food frequency questionnaire to assess nutrient intake in New Zealand infants aged 9 to 12 months : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand

Background: Obtaining information on dietary intake in infants is challenging but necessary to help understand the relationship between diet and growth and development. Food frequency questionnaires (FFQ) are commonly used to investigate dietary intake as they are suited for use in large population groups, can determine intake over multiple days and minimise participant and researcher burden, and associated costs. FFQs need to be specific to the population they are to be used in and validated so that their results can be interpreted with greater confidence. There are currently no simple, validated dietary assessment methods that are available to assess nutrient intake for New Zealand infants. Objective: To validate a complementary food frequency questionnaire (CFFQ) against a reference method of a four-day weighed food record (4dWFR) for assessing nutrient intakes of New Zealand infants aged 9 to 12 months. A secondary objective was to assess the reproducibility of the CFFQ by having it completed on two separate occasions, four weeks apart. Methods: A cross-sectional study design was used including ninety-five infants aged 10 ± 1 months and their primary caregiver, who completed the CFFQ twice (CFFQ-1 and CFFQ-2), approximately four weeks apart (to assess reproducibility). Four days of weighed food records (4dWFR) were collected on non-consecutive days between CFFQ administrations (validity). Validity and reproducibility were assessed for intakes of energy, macronutrients and micronutrients using paired t-tests, Pearson’s correlation coefficients, cross-classification and Bland-Altman analysis. Two data sets were created, one that included milk intake (breast milk and formula) and one that excluded milk intake. The data was also adjusted for energy intake, before being reassessed for validity and reproducibility. Results: For validity, most nutrient intakes from the CFFQ were comparable to the 4dWFR (range <1% up to 27% different). The CFFQ produced significantly higher nutrient intakes for fat and saturated fat, but significantly lower nutrient intakes for carbohydrate, fibre, folate, potassium, thiamin, riboflavin, niacin and vitamin C (p<0.01). Correlation coefficients ranged from r=0.18 (saturated fat) to r=0.81 (iron; mean r=0.52). Over half of participants had the same tertile classification by both the 4dWFR and the CFFQ (mean 53.9%, range 39.0% (selenium) to 67.4% (iron)). Between 2.1% (iron and calcium) and 14.7% (saturated fat) of participants (mean 7.1%) were misclassified into opposite tertiles. Most of the nutrients showed acceptable agreement between methods (κ=0.20–0.60). Saturated fat and selenium showed poor agreement (κ<0.20) and iron showed good agreement (κ>0.60). Removing milk intake weakened the correlations (range r=0.21 for vitamin E to r=0.60 for niacin, mean r=0.44) and reduced the agreement between methods (50.3% correctly classified and 9.2% grossly misclassified). Adjustment for energy intake showed comparable correlation coefficients (range r=0.24 for fibre and r=0.78 for calcium and iron, mean r=0.52) and improved the agreement between methods (56.2% correctly classified and 6.8% grossly misclassified). The CFFQ had adequate performance for reproducibility for all nutrients and energy with acceptable correlations (r≥0.20) and good cross-classification (>50% correctly classified and <10% grossly misclassified) apart from fat and saturated fat (40.9% and 47.3% correctly classified, respectively). All nutrients showed acceptable to good agreement between the CFFQ-1 and CFFQ-2 (κ>0.20). When milk intake was excluded and when the data was adjusted for energy intake, there was comparable acceptable to good correlations and cross-classification. Conclusion: Although there were some differences in absolute energy and nutrient intakes between the methods, the CFFQ appears to have acceptable validity for assessing 14 nutrients and good reproducibility for assessing 18 nutrients and energy in infants aged 9-12 months. The CFFQ could be used in future research to investigate infant nutrient intakes where using a simple tool with little participant burden is beneficial

Misreporting of energy and micronutrient intake estimated by food records and 24 hour recalls, control and adjustment methods in practice

In order to assess nutritional adequacy, valid estimates of nutrient intake are required. One of the main errors in dietary assessment is misreporting. The objective was to review the extent, nature and determinants of misreporting in dietary assessment, how this affects reported intakes of micronutrients and how this is identified and measured, and to identify the best ways of dealing with misreporting when interpreting results. A systematic literature search was conducted for studies of misreporting of dietary intake in adults by 24 hour recalls or by estimated or weighed food records, published up to March 2008. Thirty-seven relevant studies were identified. Possible causes of misreporting were identified. Methods most used to identify misreporting were the Goldberg cut-off (46 % studies) and the doubly labelled water technique (24 % studies). The magnitude of misreporting of energy intake was similar in all three dietary assessment methods. The percentage of under-reporters was about 30 % and energy intake was underestimated by approximately 15 %. Seven papers presented usable data for micronutrient intake. Absolute intakes of Fe, Ca and vitamin C (the three micronutrients addressed in all papers) were on average 30 % lower in low-energy reporters (LER) than that in non-LER and, although results were not consistent, there was a tendency for micronutrient density to be higher in LER. Excluding underreporters or using energy adjustment methods for micronutrient intakes is discussed. Residual method of energy adjustment seems to be a good tool for practice to decrease an influence of misreporting when interpreting results of studies based on food records and 24 hour recall

Measuring food provision in Western Australian long day care (LDC) services: A weighed food record method/protocol at a service level

Background There are currently 1.3 million children utilising Early Childhood Education and Care (ECEC) services in Australia. Long day care (LDC), family day care and out of school hours care currently provide this service in different environments. This research reports findings from a LDC perspective. Children can consume 40–67% of their food intake whilst at LDC services, this highlights the importance of monitoring food provision at a service level. There are several methods to measure food provision which typically focus on intake at an individual level. There is limited evidence of measuring food provision accurately at a service level and for young children. Accurate and consistent dietary assessment methods are required to determine compliance with dietary guidelines and to provide rigour for comparison between studies. Methods Convenience sampling was used to recruit 30 LDC services and food provision assessed over two consecutive days. To ensure consistency, trained researchers weighed raw food ingredients used in food preparation at each service. Food and food weights were allocated to food groups to determine average serves of food group provision at morning tea, lunch and afternoon tea per child. All data were entered into Foodworks for dietary analysis and compliance with dietary guidelines was assessed using Wilcoxon signed-rank and one-sample t-tests (SPSS). Discussion This paper outlines the process of data collection for the measurement and auditing of food provision and food waste at a service level. There is an urgent need to ensure that food provision at a service level complies with current dietary guidelines and is accurately assessed. Following a standard method of data collection will allow a more accurate comparison between studies and allow change to be monitored more accurately over time to guide decision makers. Trial registration As this research project is conducted at a service level and not a clinical trial, registration was not required

Reproducibility of Dietary Intake Measurement From Diet Diaries, Photographic Food Records, and a Novel Sensor Method

Objective: No data currently exist on the reproducibility of photographic food records compared to diet diaries, two commonly used methods to measure dietary intake. Our aim was to examine the reproducibility of diet diaries, photographic food records, and a novel electronic sensor, consisting of counts of chews and swallows using wearable sensors and video analysis, for estimating energy intake. Method: This was a retrospective analysis of data from a previous study, in which 30 participants (15 female), aged 29 ± 12 y and having a BMI of 27.9 ± 5.5, consumed three identical meals on different days. Four different methods were used to estimate total mass and energy intake on each day: (1) weighed food record; (2) photographic food record; (3) diet diary; and (4) novel mathematical model based on counts of chews and swallows (CCS models) obtained via the use of electronic sensors and video monitoring system. The study staff conducted weighed food records for all meals, took pre- and post-meal photographs, and ensured that diet diaries were completed by participants at the end of each meal. All methods were compared against the weighed food record, which was used as the reference method. Results: Reproducibility was significantly different between the diet diary and photographic food record for total energy intake (p = 0.004). The photographic record had greater reproducibility vs. the diet diary for all parameters measured. For total energy intake, the novel sensor method exhibited good reproducibility (repeatability coefficient (RC) of 59.9 (45.9, 70.4), which was better than that for the diet diary [RC = 79.6 (55.5, 103.3)] but not as repeatable as the photographic method [RC = 43.4 (32.1, 53.9)]. Conclusion: Photographic food records offer superior precision to the diet diary and, therefore, would be valuable for longitudinal studies with repeated measures of dietary intake. A novel electronic sensor also shows promise for the collection of longitudinal dietary intake data.Fil: Fontana, Juan Manuel. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Pan, Zhaoxing. University of Colorado; Estados UnidosFil: Sazonov, Edward S.. University of Alabama; Estados UnidosFil: McCrory, Megan A.. Boston University; Estados UnidosFil: Thomas, J. Graham. University Brown; Estados UnidosFil: McGrane, Kelli S.. University of Colorado; Estados UnidosFil: Marden, Tyson. University of Colorado; Estados UnidosFil: Higgins, Janine A.. University of Colorado; Estados Unido

Repeatability and validity of a food frequency questionnaire in free-living older people in relation to cognitive function

Objectives: To determine the repeatability and validity of a self-administered, 175-item food frequency questionnaire (FFQ) in free-living older people and to assess whether these are influenced by cognitive function. Participants and setting: 189 free-living people aged 64-80y were recruited from participants in a previous study. Design: To assess repeatability, 102 (52M, 50F) participants completed the FFQ on two occasions three months apart. To assess validity, another 87 participants (44 M, 43 F) completed the FFQ and a four-day weighed diet record three months later. 25 nutrients were studied. Results: For repeatability, Spearman rank correlation coefficients were above 0.35 (p<0.05) for all nutrients. Cohen’s weighted Kappa was above 0.4 for all nutrients except starch, riboflavin, retinol, β-carotene, and calcium. There were no substantial differences in correlation coefficients between sub-groups divided by short-term memory test score. There was no clear pattern for correlation coefficients in sub-groups divided by executive function test score. For validity, the Spearman rank correlation coefficients were above 0.2 (p<0.05) for all nutrients except fat, mono-unsaturated fatty acids, niacin equivalents and vitamin D, and Cohen’s weighted kappa was above 0.4 for alcohol and was above 0.2 for 13 other nutrients. Participants in the lowest-score groups of short-term memory and executive function had the lowest median Spearman correlation coefficient. Conclusions: The FFQ had reasonable repeatability and validity in ranking nutrient intakes in this population though the results varied between nutrients. Poor short-term memory or executive function may affect FFQ validity in ranking nutrient intakes

Minimum dietary diversity for women of reproductive age (MDD-W) data collection : validity of the list-based and open recall methods as compared to weighed food record

Minimum dietary diversity for women of reproductive age (MDD-W) was validated as a population-level proxy of micronutrient adequacy, with indicator data collection proposed as either list-based or open recall. No study has assessed the validity of these two non-quantitative proxy methods against weighed food records (WFR). We assessed the measurement agreement of list-based and open recall methods as compared to WFR (i.e., reference method of individual quantitative dietary assessment) for achieving MDD-W and an ordinal food group diversity score. Applying a non-inferiority design, data were collected from non-pregnant women of reproductive age in Cambodia (n = 430), Ethiopia (n = 431), and Zambia (n = 476). For the pooled sample (n = 1337), proportions achieving MDD-W from both proxy methods were compared to WFR proportion by McNemar’s chi-square tests, Cohen’s kappa, and receiver operating characteristic (ROC) analysis. Ordinal food group diversity (0–10) was compared by Wilcoxon matched-pairs signed-rank tests, intraclass correlation coefficients (ICC), and weighted kappa. MDD-W food groups that were most frequently misreported (i.e., type I and II errors) by the proxy methods were determined. Our findings indicate statistically significant differences in proportions achieving MDD-W, ordinal food group diversity scores, and ROC curves between both proxy methods and WFR (p < 0.001). List-based and open recall methods overreported women achieving MDD-W by 16 and 10 percentage points, respectively, as compared to WFR (proportion achieving MDD-W: 30%). ICC values between list-based or open recall and WFR were 0.50 and 0.55, respectively. Simple and weighted kappa values both indicated moderate agreement between list-based or open recall against WFR. Food groups most likely to be misreported using proxy methods were beans and peas, dark green leafy vegetables, vitamin A-rich fruit and vegetables, and other fruits. Our study provides statistical evidence for overreporting of both list-based and open recall methods for assessing prevalence of MDD-W or ordinal food group diversity score in women of reproductive age in low- and middle-income countries. Operationalizing MDD-W through qualitative recall methods should consider potential trade-offs between accuracy and simplicity

Relative validation of a food frequency questionnaire to estimate food intake in an adult population

Background: Scientifically valid descriptions of dietary intake at population level are crucial for investigating diet effects on health and disease. Food frequency questionnaires (FFQs) are the most common dietary tools used in large epidemiological studies. Objective: To examine the relative validity of a newly developed FFQ to be used as dietary assessment tool in epidemiological studies. Design: Validity was evaluated by comparing the FFQ and a 4-day weighed food record (4-d FR) at nutrient and food group levels, Spearman’s correlations, Bland–Altman analysis and Wilcoxon rank sum tests were used. Fifty-six participants completed a paper format FFQ and a 4-d FR within 4 weeks. Results: Corrected correlations between the two instruments ranged from 0.27 (carbohydrates) to 0.55 (protein), and at food group level from 0.09 (soup) to 0.92 (alcohol). Nine out of 25 food groups showed correlations > 0.5, indicating moderate validity. More than half the food groups were overestimated in the FFQ, especially vegetables (82.8%) and fruits (56.3%). Water, tea and coffee were underestimated (–14.0%). Conclusions: The FFQ showed moderate relative validity for protein and the food groups fruits, egg, meat, sausage, nuts, salty snacks and beverages. This study supports the use of the FFQ as an acceptable tool for assessing nutrition as a health determinant in large epidemiological studies

Evaluation of acceptability, functionality, and validity of a passive image-based dietary intake assessment method in adults and children of Ghanaian and Kenyan origin living in London, UK

BACKGROUND: Accurate estimation of dietary intake is challenging. However, whilst some progress has been made in high-income countries, low- and middle-income countries (LMICs) remain behind, contributing to critical nutritional data gaps. This study aimed to validate an objective, passive image-based dietary intake assessment method against weighed food records in London, UK, for onward deployment to LMICs. METHODS: Wearable camera devices were used to capture food intake on eating occasions in 18 adults and 17 children of Ghanaian and Kenyan origin living in London. Participants were provided pre-weighed meals of Ghanaian and Kenyan cuisine and camera devices to automatically capture images of the eating occasions. Food images were assessed for portion size, energy, nutrient intake, and the relative validity of the method compared to the weighed food records. RESULTS: The Pearson and Intraclass correlation coefficients of estimates of intakes of food, energy, and 19 nutrients ranged from 0.60 to 0.95 and 0.67 to 0.90, respectively. Bland-Altman analysis showed good agreement between the image-based method and the weighed food record. Under-estimation of dietary intake by the image-based method ranged from 4 to 23%. CONCLUSIONS: Passive food image capture and analysis provides an objective assessment of dietary intake comparable to weighed food records