Relative Validity and Reproducibility of a Short FoodFrequency Questionnaire to Assess Nutrient Intakesof New Zealand Adults

Validity and Reproducibility of an Electronic Food Frequency Questionnaire in Argentinian Adults

This study aimed to validate a semiquantitative electronic food frequency questionnaire (eFFQ) in estimating the intake of a comprehensive list of nutrients and bioactive compounds among adults from six regions of Argentina using multiple 24 h dietary recall (24HR) as a reference. A total of 163 adults completed two administrations of the eFFQ and four 24HRs. The paired t-test/Wilcoxon signed-rank test, Spearman/Pearson correlations, cross-classification, weighted kappa statistics, and Bland-Altman plots were employed to determine relative validity. To determine reproducibility, intraclass correlations (ICC), cross-classification, and weighted kappa statistics were calculated. For relative validity, crude correlations ranged from 0.15 to 0.57; energy adjustment and de-attenuation slightly improved most of these correlations. In cross-classification analysis, agreements within one quintile adjacent to exact agreement (EA ± 1) ranged from 52.2% to ~74%; extreme misclassifications were < 7%. For reproducibility, the crude ICC ranged from 0.29 to 0.85, showing moderate to good correlations for most nutrients. Cross-classification analysis showed agreement levels for the EA ± 1 quintile of 70.6% to 87.7%. Weighted kappa values ranged from 0.21 to 0.62. The results show that this eFFQ is relatively valid in ranking adults according to their nutrient intake and has an acceptable reproducibility, yet it slightly overestimates the intake of most nutrients.

Development and validation of the MY-VEG-FFQ: A modular web-based food-frequency questionnaire for vegetarians and vegans

BACKGROUND AND OBJECTIVE

The adoption of plant-based diets in recent years has increased the need for accurate assessments of dietary intake among vegans, vegetarians, semi-vegetarians, and omnivores. This study aimed at developing and validating a modular web-based food-frequency questionnaire (FFQ), the MY-VEG-FFQ. This FFQ was based on the original FFQ (O-FFQ) designed for the Israeli population and incorporates a skip algorithm tailored for different dietary patterns.

METHODS

A convenience sample of 101 participants, recruited via social media, completed the MY-VEG FFQ, as well as a three-day food records, which served as the gold standard for this research. Relative validity of the new FFQ was evaluated by comparing nutrients with those in the three-day food records, using Pearson correlation coefficients, Bland-Altman plots, and cross-classification. The results were compared with 90 O-FFQs that previously had been completed by vegans.

RESULTS

The validation analysis showed that nutrient-intake estimates were generally higher for the MY-VEG-FFQ than those of the three-day food records. Pearson correlation coefficients ranged between 0.25-0.63, indicating an acceptable agreement between the two tools. The proportion of participants with exact or adjacent quartile agreement was between 73%-82%. The Bland-Altman analysis revealed overestimation of nutrient intake via the MY-VEG-FFQ. Compared to the O-FFQ, vegans who completed the MY-VEG-FFQ reported consumption of more food items. Additionally, the MY-VEG-FFQ showed a significantly higher intake of most macro- and micronutrients.

CONCLUSIONS

The My-VEG-FFQ demonstrated reasonable validity in assessing dietary intake among people who followed a plant-based diet. However, it tended to overestimate nutrient intake compared to the three-day food records. The development of a modular web-based FFQ with a skip algorithm tailored for specific dietary patterns, fills a crucial gap in accurately assessing the dietary intake of these populations. The MY-VEG-FFQ offers a practical and cost-effective tool for evaluating long-term dietary consumption among people who follow different dietary patterns.

He Rourou Whai Painga, an Aotearoa New Zealand dietary pattern for metabolic health and whānau wellbeing: protocol for a randomized controlled trial

Background

Cardiometabolic diseases are highly prevalent in Aotearoa New Zealand. Dietary intake is a modifiable risk factor for such diseases and certain dietary patterns, specifically the Mediterranean diet (MedDiet), are associated with improved metabolic health. This study aims to test whether an intervention including a Mediterranean dietary pattern incorporating high quality New Zealand foods (NZMedDiet pattern) and behavior change science can improve the metabolic health of participants and their household/whānau.

Methods and analysis

This is a multi-center, three-stage trial with two parallel group superiority randomized controlled trials (RCTs), and a longitudinal cohort study embedded within the trial design. The first RCT (RCT 1) is a comparison of the NZMedDiet pattern compared to usual diet for 12 weeks. The Behavior Change Wheel was used to select and implement strategies to support participant adherence to the NZMedDiet, such as web-based nutrition education on healthy shopping and cooking. The second (RCT 2) compares online social support to no online social support for 12 weeks, administered to participants immediately following RCT 1. The third stage is a longitudinal cohort study where all participants are followed from the beginning of their start of the active intervention for 12 months in total. The primary outcome measure for each stage is the metabolic syndrome severity score (MetSSS). The duration of enrolment is 12-15 months. The total recruitment target is 200 index participants and their household/whānau members who participate with them, and the primary analyses will be intention to treat on index participants.

Discussion

The trial will test whether the NZMedDiet pattern and behavior change support improves the cardiometabolic health of people in Aotearoa New Zealand.

Clinical trial registration

https://www.anzctr.org.au/Default.aspx, identifier ACTRN12622000906752 and https://www.isrctn.com/, identifier ISRCTN89011056 (Spirit 2).

Healthy grocery delivery in the usual care for adults recovering from an acute coronary event: protocol for a three-arm randomised controlled trial

INTRODUCTION

Coronary heart disease is a major contributor to the global burden of disease. Appropriate nutrition is a cornerstone of the prevention and treatment of coronary heart disease; however, barriers including cost and access to recommended foods limits long-term adherence for many. We are conducting, in adults with coronary heart disease, a randomised controlled trial comparing usual care with two dietary interventions in which usual care is augmented by 12 weeks free delivered groceries.

METHODS AND ANALYSIS

Three hundred adults recovering from an acute coronary event will be recruited from outpatient cardiovascular services in three regions of Aotearoa New Zealand. Participants will be randomly allocated to three arms: usual care (control group), usual care and the free delivery of foods high in dietary fibre or usual care and the free delivery of foods high in unsaturated fats. Interventions duration is 12 weeks, with a further 12 months follow-up. The primary outcome measures are change in low-density lipoprotein (LDL) cholesterol concentration following the intervention, and a cost-effectiveness analysis of healthcare access and social costs in the year after the intervention. A broad range of secondary outcome measures include other blood lipids, anthropometry, glycaemia, inflammatory markers, gut microbiome, dietary biomarkers, food acceptability, dietary change and the facilitators and barriers to dietary change. The trial will determine whether the free provision of groceries known to reduce cardiovascular risk within usual care will be clinically beneficial and justify the cost of doing so. Results may also provide an indication of the relative benefit of foods rich in dietary fibre or unsaturated fats in coronary heart disease management.

ETHICS AND DISSEMINATION

This trial, The Healthy Heart Study, has Health and Disability Ethics Committee approval (20/NTB/121), underwent Māori consultation, and has locality authority to be conducted in Canterbury, Otago and Southland.

TRIAL REGISTRATION NUMBER

ACTRN12620000689976, U1111-1250-1499.

Implementing multicomponent, eHealth-based behaviour change support within a dietary intervention trial improves adherence to study-related behaviours in healthy young adults

BACKGROUND

Behaviour change science is proposed to improve participant retention and enhance the validity of trials. However, researchers seldom systematically consider and implement behaviour change strategies within trials for this purpose. The objective of this article is to evaluate how an eHealth behaviour change support (BCS) program enhances young adults' adherence to behaviours required within a dietary intervention.

METHODS

The Nine Principles framework was used to develop BCS to implement across both arms of a 10-week randomised parallel-group intervention to enhance adherence to (i) eating healthily and (ii) reporting dietary intake. Key components of the BCS included access to a dietitian-led Facebook group, text reminders, and food delivery. Effectiveness was measured using the following analyses of the 78 participants who completed the study; pre-post change in targeted dietary habits over time using a subscore of the Healthy Diet Habits Index, questionnaire to assess change in perception of barriers to eating healthily over time, Facebook group engagement, and impact evaluation of the BCS. Participants received a dietary reporting score out of 100 to assess adherence across the 10 weeks.

RESULTS

The total Healthy Diet Habits Index subscore out of 16 significantly increased from baseline to week 10 (10.6 ± 2.6 to 11.2 ± 2.6, p value < 0.05), driven primarily by an increase in vegetable consumption. Overall adherence to reporting was high across the 10 weeks, with the total population mean reporting score 90.4 ± 14.6 out of 100. Relatively low Facebook engagement was observed. Adding objects to the environment, prompts/cues and removing reward appeared to be effective components of the BCS for enhancing adherence to the target behaviours.

CONCLUSION

Using a behaviour change framework to support the design of randomised trials is a promising way to enhance participant adherence to study requirements that are typically considered burdensome, such as dietary reporting. It also enables researchers to identify and replicate effective components of BCS, including behaviour change techniques and modes of delivery. Further research into the use of different behaviour change frameworks for this purpose is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04869163; https://clinicaltrials.gov/ct2/show/NCT04869163 . (03/05/2021).

Adherence and eating experiences differ between participants following a flexitarian diet including red meat or a vegetarian diet including plant-based meat alternatives: findings from a 10-week randomised dietary intervention trial

Background

Flexitarian, vegetarian and exclusively plant-based diets are increasingly popular, particularly amongst young adults. This is the first randomised dietary intervention to investigate the health, wellbeing, and behavioural implications of consuming a basal vegetarian diet that additionally includes low-to-moderate amounts of red meat (flexitarian) compared to one containing plant-based meat alternatives (PBMAs, vegetarian) in young adults (ClinicalTrials.gov NCT04869163). The objective for the current analysis is to measure adherence to the intervention, nutrition behaviours, and participants' experience with their allocated dietary group.

Methods

Eighty healthy young adults participated in this 10-week dietary intervention as household pairs. Household pairs were randomised to receive either approximately three serves of red meat (average of 390 g cooked weight per individual, flexitarian group) or PBMAs (350-400 g per individual, vegetarian group) per week on top of a basal vegetarian diet. Participants were supported to adopt healthy eating behaviours, and this intervention was developed and implemented using a behaviour change framework. Adherence (eating allocated red meat or PBMA, abstaining from animal-based foods not provided by researchers) was continuously monitored, with total scores calculated at the end of the 10-week intervention period. Eating experiences were measured by the Positive Eating Scale and a purpose-designed exit survey, and a food frequency questionnaire measured dietary intake. Analyses used mixed effects modeling taking household clustering into account.

Results

The total average adherence score was 91.5 (SD = 9.0) out of a possible 100, with participants in the flexitarian group scoring higher (96.1, SD = 4.6, compared to 86.7, SD = 10.0; p < 0.001). Those receiving red meat were generally more satisfied with this allocation compared to those receiving the PBMAs, even though a leading motivation for participants joining the study was an opportunity to try plant-based eating (35% expressed that their interest in taking part was related to trying plant-based eating). Participants in both intervention groups had increased vegetable intake (p < 0.001), and reported more positive eating experiences (p = 0.020) and satisfaction with eating (p = 0.021) at the end of the 10-week intervention relative to baseline values.

Conclusion

Methods to encourage engagement with the trial were successful, as participants demonstrated excellent adherence to the intervention. Observed differences in participants' adherence and experiences between flexitarian and vegetarian groups holds implications for the adoption of healthy, sustainable dietary patterns beyond this study alone.

Habitual Dietary Patterns, Nutrient Intakes, and Adherence to the Mediterranean Diet among New Zealand Adults: The NZ MED Cross-Sectional Study

There is increasing evidence that adherence to a Mediterranean dietary pattern reduces the incidence of diet-related diseases. To date, the habitual dietary intake of New Zealand (NZ) adults has not been examined in relation to its alignment with a Mediterranean-style dietary pattern. This study aimed to define the habitual dietary patterns, nutrient intakes, and adherence to the Mediterranean Diet in a sample of 1012 NZ adults (86% female, mean age 48 ± 16 years) who had their diabetes risk defined by the Australian Type 2 Diabetes Risk Assessment Tool (AUSDRISK). Dietary intakes were collected using a validated semi-quantitative NZ food frequency questionnaire, and dietary patterns were identified using principal component analysis. Reported intakes from the FFQ were used in conjunction with the Mediterranean-Style Dietary Pattern Score (MSDPS) to determine adherence to a Mediterranean dietary pattern. Mixed linear models were used to analyze the association between dietary patterns and MSDPS with demographics, health factors, and nutrient intakes. Two distinct dietary patterns were identified: Discretionary (positive loadings on processed meat, meat/poultry, fast food, sweet drinks, and sugar, sweets, and baked good) and Guideline (positive loadings on vegetables, eggs/beans, and fruits). Adherence to dietary patterns and diet quality was associated with age and ethnicity. Dietary patterns were also associated with sex. Adherence to a Mediterranean dietary pattern defined by the MSDPS was low, indicating that a significant shift in food choices will be required if the Mediterranean Diet is to be adopted in the NZ population.

Development of eHealth-Based Behavior Change Support for Young Adults Using the Nine Principles Framework

Implementing behavior strategies into nutrition research requires consideration. The Nine Principles framework was used to develop an eHealth behavior change support (BCS) program to enhance young adults' adherence to (1) eating healthily and (2) recording dietary intake when participating in a randomized control trial. The Theory of Planned Behavior and qualitative focus group data informed a 10-week pilot of the BCS delivered on Facebook and texts. The BCS appeared to support optimal dietary recording and maintained dietary behaviors, suggesting using a framework underpinned by theory and user-centered design may be a promising avenue to enhance adherence in randomized control trials.

Evaluation of Preconception Dietary Patterns in Women Enrolled in a Multisite Study

Background

Diet indices are widely used in nutritional research across communities but do not "capture" the full extent of diet variability across multiple countries. Empirically derived dietary patterns can provide additional information because they reflect combinations of foods potentially associated with health outcomes. Limited studies have evaluated preconception dietary patterns in heterogeneous populations.

Objectives

In the multisite Nutritional Intervention Preconception and During Pregnancy to Maintain Healthy Glucose Metabolism and Offspring Health (NiPPeR) study, the secondary aims included: 1) derive pooled and site-specific preconception dietary patterns, and 2) evaluate these patterns using anthropometric measures and metabolic biomarkers.

Methods

Women planning pregnancy (n = 1720) in the United Kingdom, Singapore, and New Zealand completed interviewer-administered harmonized FFQs and lifestyle questionnaires at recruitment. Across-cohort ("pooled") and site-specific dietary patterns were derived, and associations between dietary pattern scores and BMI, waist-to-hip ratio, plasma lipids, and glycemia assessed using multivariable linear regression, expressing results as SD change in outcome per SD change in dietary pattern score.

Results

The pooled analysis identified 3 dietary patterns: "Vegetables/Fruits/Nuts" ("Healthy"), "Fried potatoes/Processed meat/Sweetened beverages" ("Less Healthy"), and "Fish/Poultry/Noodles/Rice" ("Mixed"). The "Healthy" and "Less Healthy" pooled pattern scores were highly correlated with their corresponding site-specific dietary pattern scores ("Healthy": ρ = 0.87-0.93; "Less Healthy": ρ = 0.65-0.88). Women with higher scores for the "Healthy" pooled pattern had a lower waist-to-hip ratio (standardized β: -0.10; 95% CI: -0.18, -0.01); those with higher scores for the "Less Healthy" pooled pattern had a higher BMI (standardized β: 0.17; 95% CI: 0.09, 0.24), higher LDL cholesterol (standardized β: 0.10; 95% CI: 0.01, 0.19), and less optimal glucose profiles. However, we noted higher adherence to the "Healthy" pooled pattern with higher BMI.

Conclusions

The "Healthy" and "Less Healthy" pooled patterns were comparable to the corresponding site-specific patterns. Although the associations between these patterns and objective anthropometric/metabolic measures were largely in the expected directions, future studies are required to confirm these findings.This trial is registered at clinicaltrials.gov (NCT02509988).

Relative Validity and Reproducibility of a Semi-Quantitative Food Frequency Questionnaire for Determining Nutrient Intake in Older Adults in New Zealand: The REACH Study

Dietary intake is an important predictor of health and disease outcomes. This cross-sectional study evaluated the relative validity and reproducibility of a semi-quantitative food frequency questionnaire (FFQ) for assessing energy and nutrient intake in older adults. Dietary data were collected 2018–2019 in Auckland, New Zealand from a convenience sample of community-dwelling adults (65–74 years, n = 294, 37% male) using a 109-item self-administered FFQ at baseline (FFQ1) and four weeks later to assess reproducibility. FFQ1 was compared to a four-day food record to determine relative validity. Agreement between dietary assessment tools was assessed for both raw and energy-adjusted nutrient intakes using paired t-tests, correlation coefficients, weighted kappa statistic, Bland–Altman plots, and linear regression analysis. Energy adjustments moderately improved the relative validity and reproducibility for most nutrients. For energy and energy-adjusted nutrient intakes, the mean correlation coefficients were 0.38 (validity) and 0.65 (reproducibility); the mean weighted kappa statistics were 0.27 (validity) and 0.51 (reproducibility). A significant slope of bias was present in 54% (validity) and 25% (reproducibility) of Bland–Altman plots. The Researching Eating, Activity, and Cognitive Health (REACH) FFQ has acceptable relative validity and good reproducibility for ranking nutrient intakes in older New Zealand adults, but is less suitable for assessing absolute nutrient intakes.

A Modern Flexitarian Dietary Intervention Incorporating Web-Based Nutrition Education in Healthy Young Adults: Protocol for a Randomized Controlled Trial

BACKGROUND

The trend of flexitarian eating patterns is on the rise, with young adults among the biggest adopters claiming health and environmental reasons to reduce red meat intake. Nutrient-dense meat and animal products are often the lynchpin of these diets, even when consumed only occasionally and in moderate amounts. Red meat provides forms and concentrations of essential proteins, lipids, and micronutrients that are scarce in exclusively vegetarian regimens.

OBJECTIVE

The aim of this study is to consider the effects of moderate consumption of lean red meat as part of an otherwise vegetarian balanced diet and its impact on biomarkers of sustained health and well-being.

METHODS

A cohort of healthy, young (20-34 years old, n=80) male and female participants will take part in a 2-arm, parallel randomized controlled trial (RCT) for a duration of 12 weeks, with a 3-month posttrial follow-up. The trial will commence with a 2-week assessment period followed by allocation to the intervention arms. The intervention will include the consumption of red meat or meat alternatives 3 times per week for 10 weeks. Blood samples of the participants will be collected to measure changes in erythrocyte fatty acid distribution, circulating amino acids, neurotransmitters, markers of mineral status, and inflammatory markers. Questionnaires to assess well-being and mental health will be undertaken every 2 weeks. Body composition, physical function, and blood parameters will be assessed at allocation (t₀), week 5 into the intervention (t₅), and post intervention (t₁₀).

RESULTS

The protocol has been developed using the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) checklist and the outcomes will be reported in accordance with the CONSORT (Consolidated Standards of Reporting Trials) guidelines. The trial was approved by the New Zealand Ministry of Health's Health and Disability Ethics Committees (protocol 20/STH/157). The results of this study will be communicated via publication.

CONCLUSIONS

To our knowledge, this is the first RCT investigating the overarching health consequences of consuming pasture-fed red meat or no meat as part of a healthy diet.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04869163; https://clinicaltrials.gov/ct2/show/NCT04869163.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/30909.

A Food Frequency Questionnaire for Hemodialysis Patients in Bangladesh (BDHD-FFQ): Development and Validation

Diet is a recognized risk factor and cornerstone for chronic kidney disease (CKD) management; however, a tool to assess dietary intake among Bangladeshi dialysis patients is scarce. This study aims to validate a prototype Bangladeshi Hemodialysis Food Frequency Questionnaire (BDHD-FFQ) against 3-day dietary recall (3DDR) and corresponding serum biomarkers. Nutrients of interest were energy, macronutrients, potassium, phosphate, iron, sodium and calcium. The BDHD-FFQ, comprising 132 food items, was developed from 606 24-h recalls and had undergone face and content validation. Comprehensive facets of relative validity were ascertained using six statistical tests (correlation coefficient, percent difference, paired t-test, cross-quartiles classification, weighted kappa, and Bland-Altman analysis). Overall, the BDHD-FFQ showed acceptable to good correlations (p < 0.05) with 3DDR for the concerned nutrients in unadjusted and energy-adjusted models, but this correlation was diminished when adjusted for other covariates (age, gender, and BMI). Phosphate and potassium intake, estimated by the BDHD-FFQ, also correlated well with the corresponding serum biomarkers (p < 0.01) when compared to 3DDR (p > 0.05). Cross-quartile classification indicated that <10% of patients were incorrectly classified. Weighted kappa statistics showed agreement with all but iron. Bland-Altman analysis showed positive mean differences were observed for all nutrients when compared to 3DDR, whilst energy, carbohydrates, fat, iron, sodium, and potassium had percentage data points within the limit of agreement (mean ± 1.96 SD), above 95%. In summary, the BDHD-FFQ demonstrated an acceptable relative validity for most of the nutrients as four out of the six statistical tests fulfilled the cut-off standard in assessing dietary intake of CKD patients in Bangladesh.

Validity of the food frequency questionnaire for adults in nutritional epidemiological studies: A systematic review and meta-analysis

As the most widely used tool for assessing dietary intake, the validity of food frequency questionnaires (FFQs) should be evaluated before application. A comprehensive search of the PubMed and Web of Science databases was conducted for publications from January 2000 to April 1, 2020. Pooled estimates were calculated for correlation coefficients and mean differences for energy and 61 nutrients between FFQs and standard methods. The literature search identified 130 articles that included 21,494 participants. Subgroup analyses according to the number of administrations of the reference method, sample size, administration methods, FFQ items, reference periods, quality of the studies, gender, and regions were also performed. We conducted a meta-analysis by summarizing the available evidence to comprehensively assess the validity of FFQs stratified by the reference method type (24-hour recall (24HRs) and food records (FRs). We also performed subgroup analyses to examine the impact on the final summary estimates. After a meta-analysis of the FFQs' validity correlation coefficients of the included studies, this study showed that the range (median) of the validity coefficients of the 24HRs as reference methods was 0.220-0.770 (0.416), and for the FRs, it was 0.173-0.735 (0.373), which indicated that FFQs were suitable to assess the overall dietary intake in nutritional epidemiological studies. The results of the subgroup analysis showed that the number of administrations of the reference method, administration mode, number of items, reference periods, sample size, and gender mainly affected the validity correlation of FFQs.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1966737 .

Stepwise tailoring and test-retest of reproducibility of an ethnic-specific FFQ to estimate nutrient intakes for South Asians in New Zealand

OBJECTIVE

To develop and test-retest the reproducibility of an ethnic-specific FFQ to estimate nutrient intakes for South Asians (SA) in New Zealand (NZ).

DESIGN

Using culturally appropriate methods, the NZFFQ, a validated dietary assessment tool for NZ adults, was modified to include SA food items by analysing foods consumed by SA participants of the Adult Nutrition Survey, in-person audit of ethnic food stores and a web scan of ethnic food store websites in NZ. This was further refined via three focus group discussions, and the resulting New Zealand South Asian Food Frequency Questionnaire (NZSAFFQ) was tested for reproducibility.

SETTING

Auckland and Dunedin, NZ.

PARTICIPANTS

Twenty-nine and 110 males and females aged 25-59 years of SA ethnicity participated in the focus group discussions and the test-retest, respectively.

RESULTS

The development phase resulted in a SA-specific FFQ comprising of 11 food groups and 180 food items. Test-retest of the NZSAFFQ showed good reproducibility between the two FFQ administrations, 6 months apart. Most reproducibility coefficients were within or higher than the acceptable range of 0·5-0·7. The lowest intraclass correlation coefficients (ICC) were observed for β-carotene (0·47), vitamin B12 (0·50), fructose (0·55), vitamin C (0·57) and selenium (0·58), and the highest ICC were observed for alcohol (0·81), iodine (0·79) and folate (0·77). The ICC for fat ranged from 0·70 for saturated fats to 0·77 for polyunsaturated fats. The ICC for protein and energy were 0·68 and 0·72, respectively.

CONCLUSIONS

The developed FFQ showed good reproducibility to estimate nutrient intakes and warrants the need for validation of the instrument.

A meta-analysis of the reproducibility of food frequency questionnaires in nutritional epidemiological studies

BACKGROUND

Reproducibility of FFQs measures the consistency of the same subject at different time points. We performed a meta-analysis to explore the reproducibility of FFQs and factors related to reproducibility of FFQs.

METHODS AND FINDINGS

A systematic literature review was performed before July 2020 using PubMed and Web of Science databases. Pooled intraclass and Spearman correlation coefficients (95% confidence interval) were calculated to assess the reproducibility of FFQs. Subgroup analyses based on characteristics of study populations, FFQs, or study design were performed to investigate factors related to the reproducibility of FFQs. A total of 123 studies comprising 20,542 participants were eligible for the meta-analysis. The pooled crude intraclass correlation coefficients ranged from 0.499 to 0.803 and 0.499 to 0.723 for macronutrients and micronutrients, respectively. Energy-adjusted intraclass correlation coefficients ranged from 0.420 to 0.803 and 0.507 to 0.712 for macronutrients and micronutrients, respectively. The pooled crude and energy-adjusted Spearman correlation coefficients ranged from 0.548 to 0.851 and 0.441 to 0.793, respectively, for macronutrients; and from 0.573 to 0.828 and 0.510 to 0.744, respectively, for micronutrients. FFQs with more food items, 12 months as dietary recall interval (compared to less than 12 months), and a shorter time period between repeated FFQs resulted in superior FFQ reproducibility.

CONCLUSIONS

In conclusion, FFQs with correlation coefficients greater than 0.5 for most nutrients may be considered a reliable tool to measure dietary intake. To develop FFQs with higher reproducibility, the number of food items and dietary recall interval should be taken into consideration.

Validity and reproducibility of a Food Frequency Questionnaire for German descendants living in Brazil

ABSTRACT Objective This study evaluated reproducibility, relative validity, using a 24-hour recall questionnaire as a reference standard, and estimated calibration factors for a food frequency questionnaire adapted for use with German descendants living in Brazil. Methods The target population consisted of 50 volunteers, of both genders, aged over 20 years, living in a German colonization city in southern Brazil. The food frequency questionnaire was applied twice, in the first and third months of the investigation. During this period, three 24-hour recalls were applied, with an interval of one month between them. Reproducibility was estimated by the intraclass correlation coefficient. Validity was tested by the intraclass correlation coefficient, weighted kappa test and Bland-Altman method. Calibration factors were estimated using linear regression. Results Among the food frequency questionnaires, there was a strong correlation for energy and most of the nutrients corrected for energy. There was a weak correlation between a food frequency questionnaire and a 24-hour dietary recall. However, the exact concordance in the categorization in tertiles among the instruments ranged from 28% (vitamin A) to 52% (fiber and potassium). Gross values of the food frequency questionnaire were reduced with the calibration and approached the consumption data estimated by the 24-hour dietary recall. Conclusions The food frequency questionnaire showed good reproducibility, however, weak correlation with the 24-hour dietary recall. The calibration of the data obtained by the food frequency questionnaire brought them closer to the reference method.

The relationship between maternal dietary patterns during pregnancy in women with gestational diabetes mellitus and infant appetitive feeding behaviour at 6 months

Early dietary exposure may influence infant appetitive feeding behaviour, and therefore their later health. Maternal diabetes in pregnancy is associated with an increased risk of obesity in the offspring. We, therefore, examined third-trimester dietary patterns of women with gestational diabetes, their offspring's appetitive feeding behaviour at 6 months of age, and relationships between these. We used data from a prospective cohort of women with gestational diabetes and assessed maternal dietary patterns at 36 weeks' gestation using principal component analysis; infant appetitive feeding behaviour at 6 months of age using the Baby Eating Behaviour Questionnaire; and relationships between these using general linear modelling and chi-square tests. In 325 mother-infant dyads, we identified three distinct maternal dietary patterns: 'Junk,' 'Mixed,' and 'Health-conscious.' The maternal 'Health-conscious' pattern was inversely associated with 'enjoyment of food' in their sons (β - 0.24, 95% CI - 0.36 to - 0.11, p = 0.0003), but not daughters (β - 0.02, 95% CI - 0.12 to 0.08, p = 0.70), and was positively associated with 'slowness in eating,' (β 0.13, 95% CI 0.02 to 0.24, p = 0.01). Third-trimester dietary patterns in women with gestational diabetes may have sex-specific effects on infant appetitive feeding behaviour at 6 months of age.