Intake In Epidemiological Studies Research Articles

Developing and Validating Quantitative Food Frequency Questionnaire to Assess Dietary Vitamin D Intake among Adults in Indian Population.

The objective of this study is to create and validate a quantitative food frequency questionnaire (FFQ) for the assessment of Vitamin D intake among adults in Indian population. A quantitative FFQ was developed consisting of Vitamin D dietary-rich sources selected from IFCT, 2017. Further, the FFQ was validated against 24-h dietary recall from randomly selected 385 adults, both men and women above 25 years of age. The mean dietary Vitamin D intake estimated using quantitative FFQ was 402.61 ± 101.21 IU/day and that from 24-h dietary recall was 392.83 ± 120.86 IU/day. The coefficient of correlation between these two methods was 0.86 (P < 0.001) suggestive of high correlation between the two dietary assessment tools. This indicates that Vitamin D intake from FFQ and 24-h recall was similar. This efficient FFQ can assess adult Vitamin D intake in epidemiological studies, offering convenience, and ease of evaluation.

Design, development and validation of Food Frequency Questionnaires for the diabetic population: protocol for a systematic review and meta-analysis

IntroductionThe Food Frequency Questionnaire is one of the most widely used tools for estimating nutritional intake in epidemiological studies. No study has been systematically performed to comprehensively explore Food Frequency...

Dietary sodium estimation methods: accuracy and limitations of old and new methods in individuals at high cardiovascular risk.

Accurate and easy to use methods for dietary Na intake estimation in population level are lacking. We aimed at (i) estimating the mean Na intake in the group level using a variety of dietary methods (DM) and urinary methods (UM) and correlating them with 24-h urine collection (24UCol) and (ii) improving the accuracy of the existing DM. The most common DM (three 24-h dietary recalls (24DR) and FFQ) and UM (24UCol and spot urine collection using common equations) were applied. To improve the existing: (i) 24DR, discretionary Na was quantified using salt-related questions or adding extra 15 % in total Na intake and (ii) FFQ, food items rich in Na and salt-related questions were added in the standard questionnaire (NaFFQ). National and Kapodistrian University of Athens, Greece. Totally, 122 high cardiovascular risk subjects (56·0 ± 12·6 years; 55·7 % males). Mean 24 h Na excretion (24UNa) was 2810 ± 1304 mg/d. Spot urine methods overestimated the 24UNa (bias range: -1781 to -492 mg) and were moderately correlated to 24UCol (r = 0·469-0·596, P ≤ 0·01). DM underestimated the 24UNa (bias range: 877 to 1212 mg) and were weakly correlated with 24UCol. The improved DM underestimated the 24UNa (bias range: 877 to 923 mg). The NaFFQ presented the smallest bias (-290 ± 1336 mg) and the strongest correlation with 24UCol (r = 0·497, P ≤ 0·01), but wide limits of agreement in Bland-Altman plots (-2909 mg; 2329 mg), like all the other methods did. The existing methods exhibit poor accuracy. Further improvement of the newly developed NaFFQ could be promising for more accurate estimation of mean dietary Na intake in epidemiological studies. Additional validation studies are needed.

Counting Bites and Recognizing Consumed Food from Videos for Passive Dietary Monitoring.

Assessing dietary intake in epidemiological studies are predominantly based on self-reports, which are subjective, inefficient, and also prone to error. Technological approaches are therefore emerging to provide objective dietary assessments. Using only egocentric dietary intake videos, this work aims to provide accurate estimation on individual dietary intake through recognizing consumed food items and counting the number of bites taken. This is different from previous studies that rely on inertial sensing to count bites, and also previous studies that only recognize visible food items but not consumed ones. As a subject may not consume all food items visible in a meal, recognizing those consumed food items is more valuable. A new dataset that has 1,022 dietary intake video clips was constructed to validate our concept of bite counting and consumed food item recognition from egocentric videos. 12 subjects participated and 52 meals were captured. A total of 66 unique food items, including food ingredients and drinks, were labelled in the dataset along with a total of 2,039 labelled bites. Deep neural networks were used to perform bite counting and food item recognition in an end-to-end manner. Experiments have shown that counting bites directly from video clips can reach 74.15% top-1 accuracy (classifying between 0-4 bites in 20-second clips), and a MSE value of 0.312 (when using regression). Our experiments on video-based food recognition also show that recognizing consumed food items is indeed harder than recognizing visible ones, with a drop of 25% in F1 score.

Development and validation of a quantitative food frequency questionnaire to assess dietary intake among Lebanese adults

BackgroundThe food frequency questionnaire (FFQ) is the most frequently used method to assess dietary intake in epidemiological studies evaluating diet-disease association. The objective of this study was to validate a FFQ for use among Lebanese adults by evaluating various facets of validity and reproducibility.MethodsThe quantitative 164-items FFQ was validated against the average of six 24-h dietary recalls (DRs) in a sample of 238 Lebanese adults. Reproducibility of the FFQ was assessed by administering it twice within 1 month’ time interval.ResultsPositive statistically significant Pearson correlations were observed in most macro and micronutrients between the FFQ and the six 24-h DRs, ranging from 0.16 to 0.65, with two thirds of the correlation coefficients exceeding 0.3. Energy, gender, and age-adjusted statistically significant Pearson correlation coefficients ranged from 0.14 to 0.64, with two thirds of the coefficients exceeding 0.2. Intakes from the FFQ were mostly higher than those of the 24-h DRs. Mean percent difference between nutrient intakes from both dietary methods decreased remarkably after using energy-adjusted mean intakes. Values were acceptable to good for all macronutrients and several micronutrients. Cross-classification analysis revealed that around 64.3 to 83.9% of participants were classified into the same and adjacent quartile whereas grossly misclassified proportions ranged from 3.7 to 12.2%. Weighted kappa values ranged from 0.02 to 0.36 with most of them exceeding 0.2. In indirect validity analysis, key nutrient mean intakes estimated from the six 24-h DRs were significantly positively associated with tertiles of food groups derived from the FFQ. Bland Altman plots showed that the majority of data points fell within the limits of agreement (LOA) for all nutrients. As for reproducibility analysis, ICC values were all statistically significant ranging from 0.645 to 0.959 and Bland Altman plots confirmed these results.ConclusionsBased on various aspects of validity and reproducibility, and an extensive range of statistical tests, the present FFQ developed for a Lebanese community is an acceptable tool for dietary assessment and is useful for evaluating diet-disease associations in future studies.

Sugar intake among German adolescents: trends from 1990 to 2016 based on biomarker excretion in 24-h urine samples.

Trend analyses based on dietary records suggest decreases in the intakes of total sugar (TS), added and free sugar since 2005 among children and adolescents in Germany. In terms of age trends, TS intake decreased with increasing age. However, self-reported sugar intake in epidemiological studies is criticised, as it may be prone to bias due to selective underreporting. Furthermore, adolescents are more susceptible to underreporting than children. We thus analysed time and age trends in urinary fructose excretion (FE), sucrose excretion (SE) and the sum of both (FE + SE) as biomarkers for sugar intake among 8·5-16·5-year-old adolescents. Urinary sugar excretion was measured by UPLC-MS/MS in 997 24-h urine samples collected from 239 boys and 253 girls participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study cohort between 1990 and 2016. Time and age trends of log-transformed FE, SE and FE + SE were analysed using polynomial mixed-effects regression models. Between 1990 and 2016, FE as well as FE + SE decreased (linear time trend: P = 0·0272 and P < 0·0001, respectively). A minor increase in excretion during adolescence was confined to FE (linear age trend: P = 0·0017). The present 24-h excretion measurements support a previously reported dietary record-based decline in sugar intake since 2005. However, the previously seen dietary record-based decrease in TS from childhood to late adolescence was not confirmed by our biomarker analysis, suggesting a constant sugar intake for the period of adolescence.

Evaluating the Validity of a Food Frequency Questionnaire in Comparison with a 7-Day Dietary Record for Measuring Dietary Intake in a Population of Survivors of Colorectal Cancer

BackgroundFood frequency questionnaires (FFQs) are a commonly used method to assess dietary intake in epidemiological studies. It is important to evaluate the validity of FFQs in the population of interest. ObjectiveTo evaluate the validity of an FFQ for measuring dietary intake in survivors of colorectal cancer (CRC), relative to a 7-day dietary record. DesignDietary intake was assessed 1 year after the end of CRC treatment. Participants first completed a 7-day dietary record and 2 weeks later a 253-item FFQ that measured intake in the preceding month. Participants/settingData were used from a subsample of participants (n=100) enrolled in an ongoing prospective study (EnCoRe study) in the Netherlands, from 2015 to 2018. Main outcome measuresEstimated intakes of total energy, 19 nutrients, and 20 food groups as well as scoring adherence to the dietary recommendations of the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) were compared between both dietary assessment methods. Statistical analyses performedMeans and standard deviations, Spearman rank correlations corrected for within-person variation and total energy, and κ agreement between quintiles were assessed. ResultsThe median Spearman correlation corrected for within-person variation for nutrients and total energy was 0.60. Correlations >0.50 were found for 15 of 19 nutrients, with highest agreement for vitamin B-12 (0.74), polysaccharides (0.75), and alcohol (0.91). On average, 73% (range=60% to 84%) of participants were classified into the exact same or adjacent nutrient quintile. The median Spearman correlation corrected for within-person variation for food groups was 0.62. Correlations >0.50 were found for 17 of 20 food groups, with highest agreement for cereals and cereal products (0.96), fish (0.96), and potatoes (0.99). The Spearman correlation between total scores of the WCRF/AICR dietary recommendations was 0.53. ConclusionsRelative to a 7-day dietary record, the validity of an FFQ for measuring dietary intake among survivors of CRC appeared moderate to good for most nutrients and food groups.

Syringol metabolites as new biomarkers for smoked meat intake

Processed meat intake is associated with a higher risk of colorectal and stomach cancers, coronary artery disease, and type 2 diabetes and with higher mortality, but the estimation of intake of different processed meat products in this heterogeneous food group in epidemiological studies remains challenging. This work aimed at identifying novel biomarkers for processed meat intake using metabolomics. An untargeted, multi-tiered metabolomics approach based on LC-MS was applied to 33 meat products digested in vitro and secondly to urine and plasma samples from a randomized crossover dietary intervention in which 12 volunteers consumed successively 3 processed meat products (bacon, salami, and hot dog) and 2 other foods used as controls, over 3 consecutive days. The putative biomarkers were then measured in urine from 474 subjects from the European Prospective Investigation into Cancer and Nutrition (EPIC) cross-sectional study for which detailed 24-h dietary recalls and FFQs were available. Syringol and 4 derivatives of syringol were found to be characteristic of in vitro digests of smoked meat products. The same compounds present as sulfate esters in urine increased at 2 and 12 h after consumption of smoked meat products (hot dog, bacon) in the intervention study. The same syringol sulfates were also positively associated with recent or habitual consumption of smoked meat products in urine samples from participants of the EPIC cross-sectional study. These compounds showed good discriminative ability for smoked meat intake with receiver operator characteristic areas under the curve ranging from 0.78 to 0.86 and 0.74 to 0.79 for short-term and habitual intake, respectively. Four novel syringol sulfates were identified as potential biomarkers of smoked meat intake and may be used to improve assessment of smoked meat intake in epidemiological studies. This trial was registered at clinicaltrials.gov as NCT03354130.

A Systematic Review of Ecological Momentary Assessment of Diet: Implications and Perspectives for Nutritional Epidemiology

The ecological momentary assessment (EMA) of eating behaviors represents an innovative, detailed and valid approach to capture the complexity of food intake and to overcome limitations of traditional dietary assessment methods. Moreover, EMA studies might generate a large variety of data (e.g., dietary, behavioral, physical, sociopsychological, and contextual information), thereby enabling to examine concurrent exposures and events. Due to the increasing number of studies in this field of research, here we systematically reviewed EMA methods for the assessment of dietary intake in epidemiological studies, and discussed implications and perspectives for future research. Our study summarized several protocols and platforms that may be applied to assess diet in terms of eating frequency, choices, and habits. Nearly 38% of studies used an event-contingent strategy by asking participants to report foods and beverages consumed in real-time at each eating occasion. Instead, approximately 55% of studies used a signal-contingent prompting approach that notified the participants to record their dietary consumption. The remaining studies used a combination of event- and signal-contingent protocols to compare their accuracy or to improve the assessment of dietary data. Although both approaches might improve the accuracy and ecological validity of dietary assessment—also reducing the burden for participants—some limitations should nevertheless be considered. Despite these limitations, our systematic review pointed out that EMA can be applied in various fields of nutritional epidemiology, from the identification of determinants of dietary habits in healthy people to the management of patients with eating or metabolic disorders. However, more efforts should be encouraged to improve the validity and the reliability of EMA and to provide further technological innovations for public health research and interventions.

Comparison of the Utility of Total Plasma Fatty Acids Versus those in Cholesteryl Ester, Phospholipid, and Triglyceride as Biomarkers of Fatty Acid Intake.

Total plasma fatty acids or those in cholesteryl ester and phospholipids are often used to reflect fatty acid intake in epidemiological studies, but their relative performance as biomarkers of intake has not been clearly evaluated within a single population. The assessment of fatty acids in plasma fractions is more labor intensive. Thus, their use as biomarkers of dietary intake needs to be justified. Dietary intake was assessed in 200 population-based controls from a case-control study of diet and heart disease in Costa Rica by a validated food frequency questionnaire (FFQ). Fatty acids in fasting whole plasma and plasma fractions (cholesteryl ester, phospholipid, and triglyceride + free fatty acid) were measured in the 200 controls by the same laboratory using gas chromatography with flame ionization detection (GC-FID). We compared the plasma and plasma fractions data with the FFQ and adipose fatty acid profile using partial Spearman correlations to assess utility as biomarkers of intake and exposure. We found that whole plasma was equally or more strongly correlated with the FFQ and adipose fatty acid profile than either cholesteryl ester or phospholipid in most of the established markers of dietary intake, including dairy (15:0 and 17:0) and seafood (eicosapentaenoic acid and docosahexaenoic acid). Of the three plasma fractions, only fatty acids in the plasma triglyceride + free fatty acid fraction had stronger correlations with dietary intake than whole plasma. In our study population, fatty acids measured in fasting whole plasma perform as good as or better than those measured in plasma fractions as biomarkers for dietary fatty acid intake. Thus, the fractionation of plasma to evaluate long-term fatty acid intake may not be warranted.

Methodology for the assessment of added/free sugar intake in epidemiological studies.

High-sugar intake has been linked to increased risk of diseases but an accurate assessment of added/free sugar intake has always been a challenge in research. This review summarizes the methodologies for assessing added/free sugar intake reported in recent literature. Four different methods for added/free sugar-intake assessment are discussed, including the carbon isotope ratio (δC) method, Food Patterns Equivalent Database, disaggregation method and the 10-step systematic method. These methods have different strengths and limitations in terms of requirement for background knowledge, flexibility to sugar definition, level of subjectivity, accuracy and needs for recalculation/modification when used in different countries or food products. Although advances have been made in the methodologies for assessing added/free sugar intake, accurate assessment continues to be difficult. Of the methods reviewed, the 10-step systematic method could be a simpler method to provide relatively accurate estimation of added/free sugar intake. Further improvements or combining with other methods may allow more accurate and flexible estimation. Development of a completely objective biomarker for added/free sugar intake is unlikely to be achievable, therefore future research may need to focus on developing correction equations for use with biomarkers such as δC to improve their specificity to added/free sugar intake.

Evaluation at scale of microbiome-derived metabolites as biomarker of flavan-3-ol intake in epidemiological studies

The accurate assessment of dietary intake is crucial to investigate the effect of diet on health. Currently used methods, relying on self-reporting and food composition data, are known to have limitations and might not be suitable to estimate the intake of many bioactive food components. An alternative are nutritional biomarkers, which can allow an unbiased assessment of intake. They require a careful evaluation of their suitability, including: (a) the availability of a precise, accurate and robust analytical method, (b) their specificity (c) a consistent relationship with actual intake. We have evaluated human metabolites of a microbiome-derived flavan-3-ol catabolite, 5-(3′,4′-dihydroxyphenyl)-[gamma]-valerolactone (gVL), as biomarker of flavan-3-ol intake in large epidemiological studies. Flavan-3-ols are widely consumed plant bioactives, which have received considerable interest due to their potential ability to reduce CVD risk. The availability of authentic standards allowed the development of a validated high-throughput method suitable for large-scale studies. In dietary intervention studies, we could show that gVL metabolites are specific for flavan-3-ols present in tea, fruits, wine and cocoa-derived products, with a strong correlation between intake and biomarker (Spearman’s r = 0.90). This biomarker will allow for the first time to estimate flavan-3-ol intake and further investigation of associations between intake and disease risk.

Use of LC-MS for the quantitative analysis of (poly)phenol metabolites does not necessarily yield accurate results: Implications for assessing existing data and conducting future research

Plant-derived, dietary (poly)phenols have potential effects on disease-risk reduction and primary disease prevention. The characterization of (poly)phenol absorption, distribution, metabolism and excretion (ADME) is recognized as crucial step to further advance nutritional and biomedical research of these compounds; and given that (poly)phenols are extensively metabolized after ingestion, accurate assessments of their in vivo metabolites is required. It has become common practice to use unmetabolized parent compounds as reference standards when quantifying (poly)phenol metabolites by LC-MS, although little is known about the accuracy of this approach. To investigate this situation with routinely used LC-MS conditions, the signal yielded by the flavan-3-ol (−)-epicatechin was compared to those of authentic standards of its phase II and microbiota-derived metabolites. The results obtained revealed underestimations up to 94% and overestimations up to 113% of individual epicatechin metabolites. Inaccurate quantitative estimates were also obtained when phase II metabolites of other (poly)phenols were quantified by reference to their unmetabolized parent compounds. This demonstrates the importance of using structurally-identical authentic metabolites as reference compounds when quantifying (poly)phenol metabolites by LC-MS. This is of importance, not just to the accuracy of ADME studies, but for the identification and validation of (poly)phenol metabolites as biomarkers of intake in epidemiological studies.

Abstract P227: Circulating and Dietary Linoleic Acid and Prevalent Diabetes in Post-Myocardial Infarction Patients

Background: Circulating linoleic acid 18:2n-6 (LA) has been considered to reflect LA intake, but its utility as a dietary biomarker could be affected by metabolism. Objective: To study the associations of plasma and dietary LA with T2D prevalence in drug-treated patients with a history of myocardial infarction (MI). Methods: Cross-sectional analysis of baseline data in 4,072 Dutch post-MI patients of the Alpha Omega Cohort. Circulating LA (as % of total fatty acids) was assessed in plasma cholesterol esters (CE) in the total cohort and in plasma phospholipids (PL) in a random subset of 833 patients. LA intake was assessed by a 203-item validated food frequency questionnaire. Prevalence ratios of T2D and associations with metabolic parameters were estimated in plasma and dietary LA quintiles using multivariable generalized linear models adjusted for demographic, lifestyle and dietary factors. Results: Patients were on average 69 years old, 79% was male and 77% were overweight or obese. Most patients used statins (86%), antihypertensive drugs (90%) and antiplatelet drugs (84%). A total of 813 patients (20%) had T2D. Mean LA intake (±SD) was 5.7±2.2 energy%, and circulating LA was 49.9±5.0% in CE and 18.7±3.0% in PL. Spearman’s correlations of dietary LA with circulating LA in CE and PL were 0.16 and 0.10, respectively. Higher plasma LA, but not dietary LA, was significantly associated with a lower diabetes prevalence (Table 1). BMI (β= -0.07, p&lt;0.001), log non-fasting triglycerides (β= -0.01, p&lt;0.001), log non-fasting glucose (β= -0.01, p&lt;0.001), and log alcohol intake (β= -0.03, p&lt;0.001) were significantly associated with circulating LA in plasma CE. Similar associations were found for LA in plasma PL. Dietary LA was not significantly associated with T2D prevalence and metabolic parameters (all p&gt;0.05). Conclusions: Circulating LA may reflect both LA intake and metabolic state in drug-treated post-MI patients. This bears restrictions for its use as a biomarker of dietary LA intake in epidemiological studies.

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.

Use of the Method of Triads in the Validation of Sodium and Potassium Intake in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

IntroductionBiomarkers are a good choice to be used in the validation of food frequency questionnaire due to the independence of their random errors.ObjectiveTo assess the validity of the potassium and sodium intake estimated using the Food Frequency Questionnaire ELSA-Brasil.Subjects/MethodsA subsample of participants in the ELSA-Brasil cohort was included in this study in 2009. Sodium and potassium intake were estimated using three methods: Semi-quantitative food frequency questionnaire, 12-hour nocturnal urinary excretion and three 24-hour food records. Correlation coefficients were calculated between the methods, and the validity coefficient was calculated using the method of triads. The 95% confidence intervals for the validity coefficient were estimated using bootstrap sampling. Exact and adjacent agreement and disagreement of the estimated sodium and potassium intake quintiles were compared among three methods.ResultsThe sample consisted of 246 participants, aged 53±8 years, 52% of women. Validity coefficient for sodium were considered weak (рfood frequency questionnaire actual intake = 0.37 and рbiomarker actual intake = 0.21) and moderate (рfood records actual intake 0.56). The validity coefficient were higher for potassium (рfood frequency questionnaire actual intake = 0.60; рbiomarker actual intake = 0.42; рfood records actual intake = 0.79). Conclusions: The Food Frequency Questionnaire ELSA-Brasil showed good validity in estimating potassium intake in epidemiological studies. For sodium validity was weak, likely due to the non-quantification of the added salt to prepared food.

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

Next to the information on frequency of food consumption, information on consumption-day amounts is important to estimate usual dietary intake in epidemiological studies. Our objective was to identify determinants of consumption-day amounts to derive person-specific standard consumption-day amounts applicable for the estimation of usual dietary intake using separate sources to assesss information on consumption probability and amount consumed. 24-h Dietary recall data from the German National Nutrition Survey II (n=8522; aged 20-80 years) conducted between 2005 and 2007 were analysed for determinants of consumption-day amounts of thirty-eight food and beverage groups using LASSO variable selection for linear mixed-effects models. Determinants included sex, age, BMI, smoking status, years of education, household net income, living status and employment status. Most often, sex, age and smoking status were selected as predictors for consumption-day amounts across thirty-eight food groups. In contrast, living with a partner, employment status and household net income were less frequently chosen. Overall, different determinants were of relevance for different food groups. The number of selected determinants ranged from eight for coffee and juice to zero for cabbage, tea, root vegetables, leafy vegetables, fruit vegetables, legumes, offal, vegetable oils, and other fats. For the estimation of usual dietary intake in a combined approach with a 24-h food list, person-specific standard consumption-day amounts could be used. Sex, age and smoking status were shown to be the most relevant predictors in our analysis. Their impact on the estimation of usual dietary intake needs to be evaluated in future studies.

Measurement of the total choline content in 48 commercial dairy products or dairy alternatives

In this work, the total choline and choline-containing moieties (free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine, lysophosphatidylcholine and sphingomyelin) of 48 dairy products or dairy alternatives available in Canada were determined by hydrophilic interaction liquid chromatography-tandem mass spectrometry (LC–MS/MS). The average total choline content for one serving of fluid milk and alternative (i.e. 250mL as defined by Canada's Food Guide) was 32.9±2.4mg for cow's milk, 24.9±0.1mg for goat's milk and 31.2±4.2mg for soy beverage. The average total choline content for one serving of yogurt (175g) was 25.6±3.2mg. One serving of cheese (50g) provided 7.1±1.1mg of total choline on average. Our data show that for dairy products there is a negative correlation between the total choline content on a dry weight basis and the fat content (r=−0.734, P<0.001). Overall, we determined the choline content of a variety of dairy products which can supplement the data in the existing United States Department of Agriculture (USDA) choline database and be used in accurately estimating dietary choline intake in epidemiological studies. Hence, dairy products are a good source of choline with low fat products generally being a better source of choline than high fat dairy products.

Relative Validity of Micronutrient and Fiber Intake Assessed With Two New Interactive Meal- and Web-Based Food Frequency Questionnaires

BackgroundThe meal- and Web-based food frequency questionnaires, Meal-Q and MiniMeal-Q, were developed for cost-efficient assessment of dietary intake in epidemiological studies.ObjectiveThe objective of this study was to evaluate the relative validity of micronutrient and fiber intake assessed with Meal-Q and MiniMeal-Q. The reproducibility of Meal-Q was also evaluated.MethodsA total of 163 volunteer men and women aged between 20 and 63 years were recruited from Stockholm County, Sweden. Assessment of micronutrient and fiber intake with the 174-item Meal-Q was compared to a Web-based 7-day weighed food record (WFR). Two administered Meal-Q questionnaires were compared for reproducibility. The 126-item MiniMeal-Q, developed after the validation study, was evaluated in a simulated validation by using truncated Meal-Q data.ResultsThe study population consisted of approximately 80% women (129/163) with a mean age of 33 years (SD 12) who were highly educated (130/163, 80% with >12 years of education) on average. Cross-classification of quartiles with the WFR placed 69% to 90% in the same/adjacent quartile for Meal-Q and 67% to 89% for MiniMeal-Q. Bland-Altman plots with the WFR and the questionnaires showed large variances and a trend of increasing underestimation with increasing intakes. Deattenuated and energy-adjusted Spearman rank correlations between the questionnaires and the WFR were in the range ρ=.25-.69, excluding sodium that was not statistically significant. Cross-classifications of quartiles of the 2 Meal-Q administrations placed 86% to 97% in the same/adjacent quartile. Intraclass correlation coefficients for energy-adjusted intakes were in the range of .50-.76.ConclusionsWith the exception of sodium, this validation study demonstrates Meal-Q and MiniMeal-Q to be useful methods for ranking micronutrient and fiber intake in epidemiological studies with Web-based data collection.

Relative validity and reproducibility of a quantitative food frequency questionnaire for adolescents with type 1 diabetes: validity of a food frequency questionnaire.

Background. Food frequency questionnaires are used to assess dietary intake in epidemiological studies. Objective. The aim of the study was to assess the relative validity and reproducibility of a quantitative food frequency questionnaire (QFFQ) for adolescents with type 1 diabetes. Methods: Validity was evaluated by comparing the data generated by QFFQs to those of 24-hour recalls (24 hrs). QFFQs were applied twice per patient to assess reproducibility. Statistical analysis included performing t-tests, obtaining Pearson correlation coefficients when necessary, correcting measurements for randomness by the weighted kappa method, calculating intraclass correlation coefficients, and generating Bland-Altman plots (P < 0,05). Results. The total energy and nutrient intake as estimated by the QFFQs were significantly higher than those from 24 hrs. Pearson correlation coefficients for energy-adjusted, deattenuated data ranged from 0.32 (protein) to 0.75 (lipid, unsaturated fat and calcium). Weighted kappa values ranged from 0.15 (vitamin C) to 0.45 (calcium). Bland-Altman plots indicated acceptable validity. As for reproducibility, intraclass correlation coefficients ranged from 0.24 (calcium) to 0.65 (lipid), and the Bland-Altman plots showed good agreement between the two questionnaires. Conclusion: The QFFQ presented an acceptable ability to classify correctly and with good reproducibility, adolescents with type 1 diabetes according to their levels of dietary intake.