De-attenuated Correlation Research Articles

Development and short evaluation of the Dutch healthy diet index for pregnant women; DHD-P.

Diet quality indices provide a quick indicator of overall diet and are commonly used in research and surveillance. We developed a Dutch Healthy Diet for pregnant women (DHD-P) index, comprising 22 components aligned with the 2021 Dutch food-based dietary guidelines for pregnant women. Our evaluation focused on assessing its performance and sensitivity to change. The DHD-P index was quantified by using a validated Food Frequency Questionnaire (FFQ) and two 24-h recalls at 12 and 24 weeks gestation completed by 24-to-41 year old pregnant women participating in the GLIMP-II study. Strength and direction of associations were evaluated based on de-attenuated correlation coefficients between FFQ and 24-h recall data at 24 weeks gestation (n = 47). Sensitivity to change was evaluated by comparing DHD-P index data assessed by both FFQ and recalls at 12 and 24 weeks gestation using paired t-tests or Wilcoxon Signed Rank Test (n = 27). De-attenuated correlation coefficients between FFQ and 24-recall data showed a good correlation for the total DHD-P score (rho = 0.57) and moderate to good correlations for component scores. FFQ as well as recall data showed comparable dietary intake at 12 and 24 weeks, suggesting minimal changes during pregnancy. Correlations over time were moderate-to-good for scores based on FFQ and low to moderate for scores based on 24hRs, indicating better reproducibility of scores based on FFQ data. Considering the moderate to good correlations, the DHD-P index appears to be an appropriate index to assess diet quality among pregnant women, and could serve as a foundation to provide dietary feedback toward healthier food choices. Studies including dietary data for all relevant food groups and nutrients are needed to substantiate our findings and further explore the DHD-P sensitivity to change.

Validating a semi-quantitative food frequency questionnaire to assess regional diet in a study of cancer in South West Nigeria.

Cancer burden is rising rapidly in Nigeria, the most populous country in sub-Saharan Africa; this trend may in part be attributable to diet. We developed and validated a semi-quantitative food frequency questionnaire (FFQ) to assess regional diet in Nigeria. We recruited 68 adult participants from rural and urban settings in South West Nigeria. We developed an FFQ administered at baseline and assessed its validity using 3 dietary recalls (baseline, 7days post baseline, 3months post baseline). We calculated Spearman's rank correlation coefficients and energy-adjusted de-attenuated correlation coefficients for food items and macronutrients. We evaluated cross-classification using quartilesof macronutrient intake. Energy-adjusted de-attenuated food item correlations between the FFQ and dietary recalls ranged from -0.08 (smoked beef/goat) to 0.73 (fried snacks) for the average intake from the first 2 recalls (2DR) and from -0.05 (smoked beef/goat) to 0.75 (smoked fish) for the average of all 3 recalls (3DR). Macronutrient correlations ranged from 0.15 (fat) to 0.37 (fiber) for the 2DR and from 0.08 (fat) to 0.41 (carbohydrates) for the 3DR. The percent of participants classified in the same quartile ranged from 16.4% (fat) to 32.8% (fiber, protein) for the 2DR and from 25.6% (fat) to 34.9% (carbohydrates) for the 3DR. Agreement improved when including adjacent quartiles, from 65.5% (carbohydrates) to 70.5% (fat, fiber) for the 2DR and from 62.8% (protein) to 76.8% (carbohydrate) for the 3DR. Our semi-quantitative FFQ was reasonably valid for ranking intake of certain foods and macronutrients in adults in South West Nigeria.

Validity and reproducibility of the intake of trans-fatty acids estimated using a FFQ and characteristics of trans-fatty acid intake of the Japanese population: the JPHC FFQ Validation Study.

We aimed to validate a method for assessing trans-fatty acid (TFA) intake in the Japanese population using the FFQ developed in the 1990s from a prospective study that was based on the Japan Public Health Center-based Prospective Cohort Study. For FFQ validation, we included 565 participants (Cohort I: n 215, Cohort II: n 350) aged 40-69 years. We used a 28-d dietary record (DR) over 1 year and two FFQ administered before and after DR assessment. We calculated total TFA intake, TFA from industrial oils (i-TFA) and TFA from ruminants (r-TFA) considering a database of measurements obtained mainly from Japan. Spearman's rank correlation coefficients (CC) were computed for validity and reproducibility. Energy adjustments were applied using two methods considering the TFA measurement: density method for TFA % of total energy and residual method for TFA g/d. The total TFA intake (% of the total energy intake) was 0·08-0·76 % (median, 0·27-0·37 %) in DR of both cohorts and was 0·00-1·13 % (median, 0·30-0·40 %) in FFQ. The i-TFA accounted for approximately 50 % of the total TFA intake in DR and approximately 40 % in FFQ. For total TFA (% of the total energy intake), CC were 0·54-0·69, and weighted κ coefficients were 0·88-0·92 for both cohorts. The de-attenuated CC was 0·46-0·62 for i-TFA (g/d) and 0·57-0·68 for r-TFA (g/d). Our study showed that the validity and reproducibility of TFA intake estimation using the FFQ were reasonable, suggesting its suitability among the Japanese population with low-TFA intake.

Validity and reliability of a semi-quantitative food frequency questionnaire in groups at high risk for cardiovascular diseases

BackgroundDiet is a modifiable risk factor for cardiovascular diseases (CVD), but there is still a lack of tools to assess dietary intakes of this high-risk population in Ningxia, China.ObjectiveWe aim to evaluate the validity and reliability of the semi-quantitative food frequency questionnaire (SFFQ) in the groups in Ningxia using a 24-hour dietary recall method.MethodTwo hundred five participants were included in the analysis. The two FFQs were 6 months apart, and during this time two 24-hour dietary recalls (24HDRs) were completed. Statistical methods were compared using inter-class correlation coefficient, unadjusted, energy-adjusted, de-attenuated correlation coefficient, quartile classification, weighted K values, and 95% limits of agreement (LOA).ResultsThe inter-class correlation coefficients between FFQ1 and FFQ2 ranged from 0.25 to 0.73. The number of subjects classified as identical or adjacent was 72.2 to 85.9%. The crude correlation coefficient between FFQs and 24HDRs was 0.30 ~ 0.81, the energy-adjusted correlation coefficient was 0.16 ~ 0.83, and the de-attenuated correlation coefficient was 0.19 ~ 0.98. Weighted k statistics and Bland-Altman plots showed acceptable agreement between FFQs and 24HDRs.ConclusionThe FFQ developed for the population at high risk of cardiovascular and cerebrovascular diseases in areas of Ningxia can be used to measure the dietary intake of nutrients and food groups reliably and validly.

Relative validity and reproducibility of a semi-quantitative food frequency questionnaire to assess fruit and vegetable consumption in school-aged children.

BackgroundSince the beneficial effects of fruit and vegetable (FV) consumption on health are well known due to the synergy of their nutrients and non-nutrients, it is crucial to have good tools to assess the FV intake. A food frequency questionnaire (FFQ) is an adequate method to estimate FV consumption, but it is necessary to relate this dietary method to the geographic and cultural environment. Therefore, this study presented the development of a semi-quantitative FFQ to estimate the FV intake in school-aged children who usually consume cooked homemade and school meals. It also aimed to evaluate the relative validity and reproducibility of the FFQ.MethodsSchool-aged children (baseline age 8 years) from 14 primary schools in the city of Zagreb participated in the study during the 2019/2020 school year. Parents/caregivers, together with the children, completed the FFQs and 3-day dietary records (3DDRs). The FFQ was designed to assess the consumption of eight food categories. The FFQ was validated using the 3DDR of 141 children (51.4% of boys), whereas the reproducibility test included the FFQ of 161 children (53.4% of boys).ResultsOf the eight food categories, FFQ overestimates the consumption of three and underestimates the consumption of three food categories (p < 0.05; Wilcoxon signed rank test) compared to the 3DDR. De-attenuated correlation coefficients estimated a significant relationship (0.217–0.384) between the FFQ and 3DDR. Cross-classification analysis revealed that overall, 28–41% of children were classified in the same quartile, whereas less than 10% of children were extremely misclassified for all food categories obtained from 3DDR and FFQ1. κw values showed fair agreement for all food categories. The Bland–Altman analysis results showed a relatively small bias for all food categories (median between -11.7 and -54.8 g), with no systematic patterns between the FFQ and 3DDR. No differences were found between food categories estimated with the FFQs on both occasions, and Spearman’s correlation coefficients ranged from 0.664 to 0.712 (p < 0.01). Cronbach’s alpha values (α > 0.700) indicate good internal consistency, and ICCs (range 0.724–0.826; p < 0.01) indicate good reproducibility of the FFQ.ConclusionThe results indicate reasonable relative validity and acceptable reproducibility of the FFQ for estimating FV consumption among school-aged children.

Reproducibility and Validity of a Food Frequency Questionnaire to Measure the Consumption of β-Carotene, β-Cryptoxanthin, Folate, Vitamin D, EPA, and DHA

ObjectivesThe authors assessed the reproducibility and validity of a 166-item semi-quantitative food frequency questionnaire (SFFQ) for a Japanese population, focusing on carotenoids, vitamin D, folate, and fatty acids. Foods for the questionnaire were chosen with a focus on nutrients associated with lifestyle-related diseases.MethodsNutrient intakes were energy-adjusted using the residual method. De-attenuated correlation coefficients between the energy-adjusted nutrients from the SFFQs and DRs were calculated to account for the within-person variation in replicate DRs or plasma biomarkers. Using the method of triads to calculate validity coefficients (VC) and 95% CIs were calculated with both DR's and plasma biomarkers as comparison methods.ResultsThe median of the deattenuated correlations between the second SFFQ and DRs was 0.56 (range, 0.34, 0.74) for 43 energy-adjusted nutrients. The correlations and 95% confidence intervals (CI) for beta-carotene, beta-cryptoxanthin, folate, vitamin D, EPA, and DHA were 0.43 (0.23, 0.60), 0.68 (0.45, 0.82), 0.69 (0.34, 0.87),0.55 (0.37, 0.68), 0.62 (0.37, 0.79), and 0.62 (0.37, 0.79), respectively. The median of intraclass correlation coefficients between the first six and second six days of DR was 0.59, and that between the first and the second SFFQ was 0.49. The VCs and 95% CIs were 0.47 (0.30, 0.73) for β-carotene, 0.59 (0.42, 0.81) for β-cryptoxanthin, 0.85 (0.51, 1.43) for folate, 0.55 (0.36, 0.87) for vitamin D, 0.61 (0.46, 0.82) for EPA, and 0.61 (0.44, 0.86) for DHA.ConclusionsThese findings suggest that a carefully designed food frequency questionnaire can reasonably estimate the intake of important nutrients in a Japanese population.Funding SourcesThe University of Nagasaki President Education Research Grants 2013, 2014, and 2016.

Reproducibility and Validity of a Food Frequency Questionnaire (FFQ) Developed for Middle-Aged and Older Adults in Semarang, Indonesia.

We assessed the reproducibility and validity of a food frequency questionnaire (FFQ) among middle-aged and older adults in Semarang, Indonesia. A total of 259 subjects aged 40–80 years completed two FFQs (nine-month apart) and nine 24 h dietary recalls (24HDRs, as a reference method). The reproducibility of the FFQ was analyzed using correlation coefficient, intra-class correlation coefficient (ICC), weighted kappa statistics and misclassification analysis. The validity was estimated by comparing the data acquired from FFQ1 and 24HDRs. The crude Pearson’s correlation coefficients and ICC for total energy and nutrients between FFQ1 and FFQ2 ranged from 0.50 to 0.81 and 0.44 to 0.78, respectively. Energy adjustment decreased the correlation coefficients for most nutrients. The crude, energy-adjusted and de-attenuated correlation coefficients for FFQ1 and 24HDRs ranged from 0.41 to 0.70, 0.31 to 0.89 and 0.54 to 0.82, respectively. The agreement rates for the same or adjacent quartile classifications were 81.1–94.6% for two FFQs and 80.7–89.6% for FFQ1 and 24HDRs. The weighted kappa values were 0.21 to 0.42 for two FFQs and 0.20 to 0.34 for FFQ1 and 24HDRs. A positive mean difference was found in the Bland–Altman analyses for energy and macronutrients. The FFQ could be acceptable for nutritional epidemiology study among Indonesians.

Validity of a food frequency questionnaire for the estimation of total polyphenol intake estimates and its major food sources in the Japanese population: the JPHC FFQ Validation Study.

We examine the validity and reproducibility of a food frequency questionnaire (FFQ) in a subsample of participants in the Japan Public Health Center-based Prospective Cohort Study using a database of polyphenol-containing foods commonly consumed in the Japanese population. Participants of the validation study were recruited from two different cohorts. In Cohort I, 215 participants completed a 28-d dietary record (DR) and the FFQ, and in Cohort II, 350 participants completed DRs and the FFQ. The total polyphenol intake estimated from the 28-d DR and FFQ were log-transformed and adjusted for energy intake by the residual method. Spearman correlation coefficients (CCs) between estimates from the FFQ and 28-d DR as well as two FFQs administered at a 1-year interval were computed. Median intakes of dietary polyphenols calculated from the DRs were 1172 mg/d for men and 1024 mg/d for women in Cohort I, and 1061 mg/d for men and 942 mg/d for women in Cohort II. The de-attenuated CCs for polyphenol intake between the DR and FFQ were 0⋅47 for men and 0⋅37 for women in Cohort I and 0⋅44 for men and 0⋅50 for women in Cohort II. Non-alcoholic beverages were the main contributor to total polyphenol intake in both men and women, accounting for 50% of total polyphenol intake regardless of cohort and gender, followed by alcoholic beverages and seasoning and spices in men, and seasoning and spices, fruits and other vegetables in women. The present study showed that this FFQ had moderate validity and reproducibility and is suitable for use in future epidemiological studies.

Development and validation of food frequency questionnaire for food and nutrient intakes of adults in Butajira, Southern Ethiopia.

We developed a culturally-specific Food Frequency Questionnaire (FFQ) to the Ethiopian context and evaluate its validity in comparison to two 24-h dietary recalls (24-HRs) of food and nutrient intake. To evaluate the validity of a culturally-specific FFQ against two 24-HRs, we used a paired t-test, Wilcoxon-signed-rank test, Correlation coefficients, cross-classification, κ and Bland-Altman analysis. The FFQ was obtained 15 d after the second 24-HR was completed. A total of 105 adults, of which 43 (41 %) were men and 62 (59 %) women, aged 20-65 years participated in this present study. Mean energy and macronutrient intake obtained from the FFQ were significantly higher than those obtained from the mean of two 24-HRs. For energy and nutrient intakes, the crude correlation ranged from 0⋅05 (total fat) to 0⋅49 (vitamin B1). The de-attenuated correlation ranged from to 0⋅10 (total fat) to 0⋅80 (vitamin A). For the majority of food groups, no significant difference was observed in the median intake of food and nutrients. Crude correlation for food groups ranged from 0⋅12 (egg) to 0⋅78 (legumes). The de-attenuated correlation ranged from 0⋅24 (egg) to 1⋅00 (meat/poultry/fish and dairy). The FFQ is valid to assess and rank individuals in terms of intake of most food groups according to high and low intake categories.

Validation of a new software eAT24 used to assess dietary intake in the adult Portuguese population.

The aim of the current study was to evaluate the accuracy of the new software eAT24 used to assess dietary intake in the National Food, Nutrition and Physical Activity Survey (IAN-AF) against urinary biomarkers: N (nitrogen), K (potassium) and Na (sodium). We conducted a cross-sectional study. Two non-consecutive 24-h dietary recalls (24-HDR) were applied, and a 24-h urine sample was collected. We examined differences between estimates from dietary and urine measures, Pearson correlation coefficients were calculated and the Bland-Altman plots were drawn. Multiple linear regression was used to evaluate the factors associated with the difference between estimates. Sub-sample from the Portuguese IAN-AF sampling frame. Ninety-five adults (men and women) aged 18-84 years. The estimated intake calculated using the dietary recall data was lower than that estimated from urinary excretion for the three biomarkers studied (protein 94·3 v. 100·4 g/d, K 3212 v. 3416 mg/d and Na 3489 v. 4003 mg/d). Considering 2 d of recall, the deattenuated correlation coefficients were 0·33, 0·64 and 0·26 for protein, K and Na, respectively. For protein, differences between dietary and urinary estimates varied according to BMI (β = -1·96, P = 0·017). The energy intake and 24-h urine volume were significantly associated with the difference between estimates for protein (β = 0·03, P < 0·001 and β = -0·02, P = 0·002, respectively), K (β = 0·71, P < 0·001 and β = -0·42, P = 0·040, respectively) and Na (β = 1·55, P < 0·001 and β = -0·81, P = 0·011, respectively). The new software eAT24 performed well in estimating protein and K intakes, but lesser so in estimating Na intake, using two non-consecutive 24-HDR.

Dietary Intake and Plasma Levels of Isoflavones Among Breast Cancer Survivors

Abstract Objectives Isoflavones, rich in soybeans, are phytoestrogens with a similar chemical structure to estrogen and their roles in breast cancer prognosis remains equivocal. We aimed to estimate dietary intake of isoflavones and soy and examine their correlations with plasma levels of isoflavones among Korean breast cancer survivors. Methods A total of 974 female breast cancer survivors (mean age, 52 years) were included in the cross-sectional study. We estimated dietary intake of soy and isoflavones using either a 3-day food record (3DR; n = 645) or a food frequency questionnaire (FFQ; n = 329). Plasma isoflavone levels were measured by liquid chromatography methods in 439 participants. We calculated total isoflavones by summing daidzein, genistein, and glycitein. We estimated % contribution of food sources to dietary isoflavone intake and Pearson correlation coefficients with plasma isoflavone levels. We calculated de-attenuated correlations among those who reported dietary intake using 3DRs to reduce within-person variation (n = 233). Results The mean daily intake of total isoflavones among Korean breast cancer survivors was 21.91 mg/d. The major sources were tofu (% contribution = 30.6%), soybean (14.2%), and soybean sprouts (12.8%). The correlation coefficients with plasma isoflavone levels were 0.19 for dietary isoflavone intake and 0.18 for soy and its products intake. The de-attenuated correlation coefficients with plasma isoflavone levels were 0.25 for dietary isoflavone intake and 0.35 for soy and its products intake. When we examined the correlation between specific type of isoflavone and circulating level of each isoflavone, the de-attenuated correlation coefficients were 0.18 for daidzein, 0.28 for genistein, and 0.25 for glycitein. Conclusions We found the highest contribution from tofu and soybean to dietary isoflavone intake and moderate correlations of dietary intakes of soy and isoflavones with plasma levels of isoflavones among Korean breast cancer survivors. Our study warrants further investigation on the roles of isoflavones in breast cancer prognosis. Funding Sources This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT, MSIT) (No. 2019R1F1A1061017).

Validation of a food frequency questionnaire as a tool for assessing dietary intake in cardiovascular disease research and surveillance in Bangladesh

BackgroundCardiovascular disease (CVD) has emerged as a major public health concern in Bangladesh. Diet is an established risk factor for CVD but a tool to assess dietary intake in Bangladesh is lacking. This study aimed to validate a food frequency questionnaire (FFQ) using the 24-h dietary recall method and corresponding nutritional biological markers among rural and urban populations of Bangladesh.MethodParticipants of both genders aged 18–60 years were included in the analysis (total n = 146, rural n = 94 and urban n = 52). Two FFQs of 166 items were administered three-months apart, during which time three 24-h dietary recalls were also completed. Participants were asked to recall their frequency of consumption over the preceding 3 months. Urine and blood samples were collected for comparison between FFQ-estimates of nutrients and their corresponding biomarkers. Methods were compared using unadjusted, energy-adjusted, de-attenuated correlation coefficients, 95% limits of agreement (LOA) and quartile classification.ResultsFair to moderate agreement for ranking energy, macro and micronutrients into quartiles was observed (weighted k value ranged from 0.22 to 0.58; p < 0.001 for unadjusted data) except for vitamin D (weighted k − 0.05) and zinc (weighted k 0.09). Correlation coefficients of crude energy, macronutrients and common micronutrients including vitamin E, thiamine, riboflavin, niacin, pyridoxine, folate, iron, magnesium, phosphorus, potassium, and sodium were moderately good, ranging from 0.42 to 0.78; p < 0.001 but only fair for vitamin A, β carotene and calcium (0.31 to 0.38; p < 0.001) and poor for vitamin D and zinc (0.02 and 0.16; p = ns, respectively). Energy-adjusted correlations were generally lower except for fat and vitamin E, and in range of − 0.017 (for calcium) to 0.686 (for fat). De-attenuated correlations were higher than unadjusted and energy- adjusted, and significant for all nutrients except for vitamin D (0.017) to 0.801 (for carbohydrate). The Bland Altman tests demonstrated that most of the coefficients were positive which indicated that FFQ provided a greater overestimation at higher intakes. More than one in three participants appeared to overestimate their food consumption based on the ratio of energy intake to basal metabolic rate cut points suggested by Goldberg. Absolute intake of macronutrients was 1.5 times higher and for micronutrients it ranged from 1.07 (sodium) to 26 times (Zinc). FFQ estimates correlated well for sodium (0.32; p < 0.001), and vitamin D (0.20; p = 0.017) with their corresponding biomarkers and iron (0.25; p = 0.003) with serum ferritin for unadjusted data. Folate, iron (with haemoglobin) and total protein showed inverse association; and fat and potassium showed poor correlation with their corresponding biomarkers for unadjusted data. However, folate showed significant positive correlation (0.189; p = 0.025) with biomarker after energy adjustment.ConclusionAlthough FFQ showed overestimation for absolute intake in comparison with 24-h recalls, the validation study demonstrated acceptable agreement for ranking dietary intakes from FFQ with 24-h recall methods and some biomarkers and therefore could be considered as a tool to measure dietary intake for research and CVD risk factors surveillance in Bangladesh. The instrument may not be appropriate for monitoring population adherence to recommended intakes because of the overestimation.

Validity of a dish composition database for estimating protein, sodium and potassium intakes against 24 h urinary excretion: comparison with a standard food composition database.

We assessed the validity of a recently developed dish composition database (DCD) against urinary biomarkers compared with a standard food composition database (FCD). Intakes of protein, Na and K were estimated by 2 × 24 h urine collections and by 4 d dietary record data based on the DCD (including 128 dishes) or FCD (including 1878 foods). Japan. A total of 161 men and 163 women aged 20-69 years. Compared with the 24 h urine-based estimates, the median intakes estimated using the DCD and FCD differed significantly for protein and Na in men and for Na and K in women. Deattenuated Spearman correlation coefficients using 24 h urine-based estimates for the intakes of protein, Na and K were lower in the DCD (respectively: 0·26, 0·15 and 0·44 in men; 0·22, 0·27 and 0·22 in women) than those in the FCD (respectively: 0·43, 0·40 and 0·59 in men; 0·33, 0·45 and 0·42 in women). When data on dish portion size reported by participants were used for estimation instead of standard portion-size data based on the DCD, the accuracy of the estimated median intakes did not change notably, whereas the deattenuated correlation coefficients improved (for protein, Na and K respectively: 0·32, 0·31 and 0·56 in men; 0·31, 0·41 and 0·39 in women). The DCD supported by individual-level information on dish portion size showed fair to moderate validity in ranking individuals according to their intakes of protein, Na and K, similar to the FCD.

Reproducibility and Validity of a Short Food Frequency Questionnaire for Dietary Assessment in Children Aged 7⁻9 Years in Spain.

The purpose of this study was to examine if the short semi-quantitative food frequency questionnaire (FFQ) is a reliable and valid tool to assess the diet of Spanish children aged 7–9 years. We collected data from 156 children of the birth cohort INMA (Infancia y Medio Ambiente (Environment and Childhood)). Children’s parents or care-givers completed a 46-item FFQ on two occasions over a 9–12-month period about the children’s diet. To explore the reproducibility of the FFQ, the nutrient and food group intake collected from the both FFQs were compared, while validity was examined by contrasting the nutrient values from the FFQs and the average of three 24-hour dietary recalls (24hDRs) taken in this period, and also with the concentration of several vitamins in the blood (carotenoids, vitamin D and α-tocopherol). Pearson and de-attenuated correlation coefficients were calculated. The average correlation coefficients for nutrient intake’s reproducibility was 0.41, ranging from 0.25 (calcium) to 0.65 (β-carotene), and for food group intake was 0.45, ranging from 0.18 (cereals) to 0.68 (sweetened beverages). Correlation coefficients slightly improved when we compared energy-adjusted intakes. The average correlation coefficients for validity against 24hDRs was 0.34 for energy-adjusted intakes, and 0.39 when de-attenuation coefficients were used. The validity coefficients against the blood concentrations of vitamins were 0.38 for β-cryptoxanthin, 0.26 for lycopene, 0,23 for α-carotene and 0.15 for β-carotene, all of them statistically significant (p < 0.05). This study suggests that our brief FFQ is a suitable tool for the dietary assessment of a wide range of nutrients and food groups in children 7–9 years, despite the low to moderate reproducibility and validity observed for some nutrients.

Validity of a Self-administered Food Frequency Questionnaire for the Estimation of Acrylamide Intake in the Japanese Population: The JPHC FFQ Validation Study.

BackgroundAcrylamide, a probable carcinogen to humans, forms during high temperature cooking. Dietary exposure to acrylamide among the Japanese population is unknown. We aimed to establish and validate a method to assess acrylamide exposure among the Japanese population using a food frequency questionnaire (FFQ) from the Japan Public Health Center-based prospective study.MethodsValidation studies for the FFQ were conducted in 1994 (Cohort I, n = 215) and 1996 (Cohort II, n = 350). The 28-day dietary records (DRs) were collected over 1 year. The FFQ was distributed before and after DR collection. Data for acrylamide exposure were based on reported measurements in Japan, and calculations considered the cooking process for specific vegetables in a home setting. Spearman’s rank correlation and weighted kappa coefficients were calculated from energy-adjusted data.ResultsMean acrylamide intake levels estimated from DRs for Cohorts I and II were 6.78 (standard deviation [SD], 3.89) µg/day and 7.25 (SD, 3.33) µg/day, and corresponding levels estimated from the FFQ were 7.03 (SD, 4.30) µg/day and 7.14 (SD, 3.38) µg/day, respectively. Deattenuated correlation coefficients for men and women were 0.54 and 0.48 in Cohort I and 0.40 and 0.37 in Cohort II, respectively. Weighted kappa coefficients were over 0.80 in all cases. The main contributing food groups from DRs were beverages, confectioneries, vegetables, potatoes and starches, and cereals.ConclusionsHigh kappa values validate the use of FFQ in epidemiological studies. The marked contribution of cooked vegetables indicates the importance of considering household cooking methods in assessing acrylamide intake levels in the Japanese population.

Comparison of the NHANES dietary screener questionnaire to the Automated Self-Administered 24-Hour Recall for Children in the Healthy Communities Study

BackgroundA dietary screener questionnaire (DSQ) was used to assess dietary outcomes among children in the Healthy Communities Study (HCS), a study of the relationships between programs and policies to prevent child obesity and child diet, physical activity and weight outcomes.MethodsTo compare dietary intake estimates derived from the DSQ against those from the Automated Self-Administered 24-Hour Recalls for Children (ASA24-Kids) among children, a measurement error model, using structural equation modelling, was utilized to estimate slopes, deattenuated correlation coefficients, and attenuation factors by age and sex, ethnicity, and BMI status.Participants/settingA randomly selected sub-sample of HCS participants aged 4–15 years in 130 communities throughout the U.S. who completed the DSQ and up to two ASA24-Kids recalls (n = 656;13% of HCS participants).ResultsFor most nutrient/foods examined, the DSQ yielded larger mean intake estimates than the ASA24-Kids, and agreement between the two measures varied by food/nutrient, age and sex, ethnicity, and BMI category. Deattenuated correlation coefficients of 0.4 or greater were observed for added sugars from SSBs (0.54), fruits and vegetables (0.40), and dairy foods (0.50). Lower deattenuated correlation coefficients were seen for total added sugars (0.37), whole grains (0.34), and fiber (0.34). Attenuation factors were most severe for total added sugars intake among overweight children, and for several other dietary outcomes among children aged 9–11 years.ConclusionsThe DSQ was found to be a tool with acceptable agreement with the ASA24-Kids for measuring multiple dietary outcomes of interest in the HCS, although there may be potential due to measurement error to underestimate results (bias towards the null). In future studies, measurement error modelling and regression calibration may be possible solutions to correct for bias due to measurement error in most food/nutrient intake estimates from the DSQ when used among children.

The Maastricht FFQ: Development and validation of a comprehensive food frequency questionnaire for the Maastricht study.

The aim of this study was to develop and validate a comprehensive food frequency questionnaire (FFQ) for The Maastricht Study, a population-based prospective cohort study in Maastricht, The Netherlands. Item selection for the FFQ was based on explained variation and contribution to intake of energy and 24 nutrients. For validation, the FFQ was completed by 135 participants (25-70 y of age) of the Nutrition Questionnaires plus study. Per person, on average 2.8 (range 1-5) telephone-based 24-h dietary recalls (24HRs), two 24-h urinary samples, and one blood sample were available. Validity of 54 nutrients and 22 food groups was assessed by ranking agreement, correlation coefficients, attenuation factors, and ultimately deattenuated correlation coefficients (validity coefficients). Median correlation coefficients for energy and macronutrients, micronutrients, and food groups were 0.45, 0.36, and 0.38, respectively. Median deattenuated correlation coefficients were 0.53 for energy and macronutrients, 0.45 for micronutrients, and 0.64 for food groups, being >0.50 for 18 of 22 macronutrients, 16 of 30 micronutrients and >0.50 for 17 of 22 food groups. The FFQ underestimated protein and potassium intake compared with 24-h urinary nitrogen and potassium excretion by -18% and -2%, respectively. Correlation coefficients ranged from 0.50 and 0.55 for (fatty) fish intake and plasma eicosapentaenoic acid and docosahexaenoic acid, and from 0.26 to 0.42 between fruit and vegetable intake and plasma carotenoids. Overall, the validity of the 253-item Maastricht FFQ was satisfactory. The comprehensiveness of this FFQ make it well suited for use in The Maastricht Study and similar populations.

Relative validity of a web-based, self-administered, 24-h dietary recall to evaluate adherence to Canadian dietary guidelines.

A new, web-based, 24-h recall (R24 W) was developed and programmed to assess adherence to Canadian dietary guidelines by automatically generating the Canadian Healthy Eating Index 2007 (C-HEI 2007). The aim of the present study was to determine the relative validity of the R24 W in terms of its ability to generate C-HEI 2007 scores that match those derived from a food record (FR). A total of 57 women and 50 men filled a 3-d FR and three 24-h food recalls with the R24 W. C-HEI 2007 was calculated with both dietary assessment tools and compared using de-attenuated correlations and kappa scores. Internal validity (correlations between total score and components) and external validity (comparison of the C-HEI 2007 by sex and age groups) were compared between the two dietary assessment methods. The average C-HEI 2007 score obtained with the R24 W (59.4 ± 11.8) was significantly lower than the one obtained with the FR (62.6 ± 11.1). However, the de-attenuated correlation coefficient between C-HEI 2007 obtained either with R24 W or FR was 0.80 (P < 0.01) and 91.6% of participants were classified in the same or adjacent quartile of C-HEI 2007 with both tools. Women obtained a higher C-HEI 2007 mean score (P < 0.01) with both methods and older adults (age: >51 y) received a higher score than younger adults (age: 18-30 y; P < 0.01) with the R24 W but not with the FR (P = 0.22). Although the R24 W yields lower C-HEI 2007 scores compared with data from FR, the classification of individuals was highly consistent between the two measurements.

Validity of a semi-quantitative food frequency questionnaire based on food groups and cooking with a protein supplement in Japanese collegiate athletes

A semi-quantitative food frequency questionnaire (FFQ) comprising a small number of food items may allow for more accurate assessment of habitual dietary intake in Japanese collegiate athletes. This study aimed to evaluate the validity and reproducibility of a commercially available FFQ (FFQg) with a newly added protein supplement item for assessing habitual dietary intake compared to the 24-hour dietary recall (24hDR) method using multiple statistical tests. A total of 108 participants (46 males) completed the FFQg on two separate days (FFQg1 and FFQg2) and 24hDRs on three non-consecutive days (two weekdays and one weekend day). Percentage differences, cross-classification analysis by quintile and Spearman’s rank correlation coefficients (CCs) were calculated to evaluate the validity and reproducibility of the FFQg. Results showed median percentage differences and de-attenuated CCs between the FFQg2 and 24hDRs were -3.4 (range: -46.8 - 25.1) and 0.33 (0.03 - 0.55), respectively, for 34 nutrients, and -16.1 (-51.4 - 45.0) and 0.34 (0.03 -0.64), respectively, for 18 food groups. Cross-classification analysis showed that median proportions of the “completely opposite category” between FFQg2 and 24hDRs for energy-adjusted intakes of nutrients and food groups were both within 5%. Median CCs for energy-adjusted intake between the FFQ1 and FFQ2 were 0.61 (0.40 - 0.82) for nutrients and 0.52 (0.40 - 0.87) for food groups. In conclusion, although estimating habitual dietary intake requires careful consideration, the FFQg offers reasonably valid measurements of ranking individuals to assess intakes of macronutrients and food groups in collegiate athletes, with a relatively good reproducibility.

The validity of a web-based FFQ assessed by doubly labelled water and multiple 24-h recalls

The aim of this study was to validate the estimated habitual dietary intake from a newly developed web-based FFQ (WebFFQ), for use in an adult population in Norway. In total, ninety-two individuals were recruited. Total energy expenditure (TEE) measured by doubly labelled water was used as the reference method for energy intake (EI) in a subsample of twenty-nine women, and multiple 24-h recalls (24HR) were used as the reference method for the relative validation of macronutrients and food groups in the entire sample. Absolute differences, ratios, crude and deattenuated correlations, cross-classifications, Bland-Altman plot and plots between misreporting of EI (EI-TEE) and the relative misreporting of food groups (WebFFQ-24HR) were used to assess the validity. Results showed that EI on group level was not significantly different from TEE measured by doubly labelled water (0·7 MJ/d), but ranking abilities were poor (r -0·18). The relative validation showed an overestimation for the majority of the variables using absolute intakes, especially for the food groups 'vegetables' and 'fish and shellfish', but an improved agreement between the test and reference tool was observed for energy adjusted intakes. Deattenuated correlation coefficients were between 0·22 and 0·89, and low levels of grossly misclassified individuals (0-3 %) were observed for the majority of the energy adjusted variables for macronutrients and food groups. In conclusion, energy estimates from the WebFFQ should be used with caution, but the estimated absolute intakes on group level and ranking abilities seem acceptable for macronutrients and most food groups.